MDI Interface

7/30/2019 MDI Interface

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EXAMPLE 1:

The end result of Example 1 will be a form containing a menu with two top-level items, File and Help.

The File menu, shown below, will have the following level-two items below it: New, Open, Save, SaveAs, Print, and Exit. Note that separator bars appear above the Save, Print, and Exit items.

The Help menu contains just one level-two item below it, About.


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To build a menu for use with your VB program, you use the Menu Editor, which appears as an icon in thetoolbar of the VB IDE. It is the circled item in the screen shot below:

Alternatively, you can invoke the Menu Editor from the Tools menu item as shown below:

To build the menu described above, perform the following steps.

1. Start a new VB project and invoke the Menu Editor using either method shown above (click the MenuEditor toolbar icon or select the Menu Editor option from the Tools menu). The Menu Editorscreen appears, as shown below:


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2. For "Caption", type &File (by placing the ampersand to the left of the "F", we establish "F" as anaccess key for the File item it enables the user to drop down the File menu by keying "Alt+F" onthe keyboard in addition to clicking the "File" item with the mouse).

For "Name", type mnuFile.

Your Menu Editor screen should look like this:


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Click the Next button.

3. Click the "right-arrow" button (shown circled below). A ellipsis (...) will appear as the next item in the

menu list, indicating that this item is a level-two item (below "File").


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For "Caption", type &New; for "Name", type mnuNew, and for "Shortcut", select Ctrl+N. Byspecifying a shortcut, you allow the user to access the associated menu item by pressing that keycombination. So here, you are providing the user three ways of invoking the "New" function: (1)clicking File, then clicking New on the menu; (2) keying Alt+F,N (because we set up an accesskey for "N" by placing an ampersand to left of "N" in "New"); or (3) keying Ctrl+N. At this point,your Menu Editor screen should look like this:


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4. For "Caption", type &Open; for "Name", type mnuOpen, and for "Shortcut", select Ctrl+O. Your Menu

Editor screen should look like this:


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5. For "Caption", type - (a hyphen), and for "Name", type mnuFileBar1. A single hyphen as the Caption

for a menu item tells VB to create a separator bar at that location. Your Menu Editor screenshould look like this:


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6. For "Caption", type &Save; for "Name", type mnuSave, and for "Shortcut", select Ctrl+S. Your Menu



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7. For "Caption", type Save &As ..., and for "Name", type mnuSaveAs. Your Menu Editor screen should

look like this:


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8. For "Caption", type -, and for "Name", type mnuFileBar2. Your Menu Editor screen should look like

this:


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9. For "Caption", type &Print;for "Name", type mnuPrint; and for "Shortcut", select Ctrl+P. Your Menu



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10. For "Caption", type -; and for "Name", type mnuFileBar3. Your Menu Editor screen should look like

this:


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11. For "Caption", type E&xit, and for "Name", type mnuExit. Your Menu Editor screen should look like

this:


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12. Click the "left-arrow" button (shown circled below). The ellipsis (...) no longer appears, meaning we

are back to the top-level items.


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For "Caption", type &Help; and for "Name", type mnuHelp. Your Menu Editor screen should look like this:


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13. Click the "right-arrow" button to create a level-two item below "Help". For "Caption", type &About; andfor "Name", type mnuAbout. Your Menu Editor screen should look like this:

14. At this point, we are done creating our menu entries, so click the OK button. That will dismiss themenu editor and return focus to the VB IDE.

15. Back in the VB IDE, your form will now have a menu, based on what you have set up in the MenuEditor. If you click on a top-level menu item (File for example), the level-two menu will drop down:


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16. Click on the New menu item. The code window for the mnuFileNew_Click event opens, as shownbelow. Note: Click is the only event that a menu item can respond to.

In thePlace mnuFileNew_Click event, place the code you want to execute when the user clicks the Newmenu item. Since this is just a demo, we will place a simple MsgBox statement in the eventprocedure:

MsgBox "Code for 'New' goes here.", vbInformation, "Menu Demo"


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17. Code similar MsgBox statements for the Open, Save, Save As, and Print menu items:

Private Sub mnuFileOpen_Click()

MsgBox "Code for 'Open' goes here.", vbInformation, "Menu Demo"

End Sub

Private Sub mnuFileSave_Click()

MsgBox "Code for 'Save' goes here.", vbInformation, "Menu Demo"

End Sub

Private Sub mnuFileSaveAs_Click()

MsgBox "Code for 'Save As' goes here.", vbInformation, "Menu Demo"

End Sub

Private Sub mnuFilePrint_Click()

MsgBox "Code for 'Print' goes here.", vbInformation, "Menu Demo"


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End Sub

18. For the Exit menu item Click event, code the statement Unload Me.

Private Sub mnuFileExit_Click()

Unload Me

End Sub

19. For the About menu item Click event, code as shown below:

Private Sub mnuHelpAbout_Click()

MsgBox "Menu Demo" & vbCrLf _

& "Copyright " & Chr$(169) & " 2004 thevbprogrammer.com", , _

"About"

End Sub

20. Run the program. Note how the code executes when you click on the various menu items. Also testthe use of the access keys (e.g., Alt+F, N) and shortcut keys (e.g., Ctrl-O).


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21. Save the program and exit VB.

Download the project files for this examplehere.

EXAMPLE 2:

This example shows you how to create a popup menu (sometimes called a context menu or a right-click menu).

1. Start a new VB project and place a label on the form. Name the label lblTestText. Set the Caption toTest Text.
http://www.vb6.us/files/VBPrograms/Menus/MenuDemo.ziphttp://www.vb6.us/files/VBPrograms/Menus/MenuDemo.ziphttp://www.vb6.us/files/VBPrograms/Menus/MenuDemo.ziphttp://www.vb6.us/files/VBPrograms/Menus/MenuDemo.zip


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2. Open the Menu Editor, and create a top-level item with a Caption value ofPopUpFormat and theName mnuPopuUpFormat. Also importantly uncheck the Visible checkbox (see the circled itembelow). In order for a menu to be a pop-up menu, it must be invisible.

3. Create the following level-two menu items below the PopUpFormat top-level menu. (When creatingthese level-two items, keep the Visible box checked.)

Caption Name

Bold mnuBoldItalic mnuItalicUnderline mnuUnderline- (hyphen) mnuFormatSepCancel mnuCancel

When done, your Menu Editor should look like this:


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4. Click OK to save your changes. Note: When you return to the IDE, you will NOT see this menu on theform (remember it's a pop-up menu, and it will only be visible when invoked through code).

5. Code the lblTestText_MouseDown event as shown below. Note that the Button parameter is testedforvbRightButton as is conventional, we only want to pop up the menu if the user right-clicks onthe label. If the user clicks the right mouse button, the PopupMenu statement is executed. It isthis statement that makes the pop-up menu appear.

Private Sub lblTestText_MouseDown(Button As Integer, _

Shift As Integer, _

X As Single, _

Y As Single)


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If Button = vbRightButton Then

PopupMenu mnuPopUpFormat, vbPopupMenuRightButton

End If

End Sub

The full syntax for the PopupMenu method, from MSDN, is:

object.PopupMenumenuname, flags,x, y, boldcommand

The PopupMenu method syntax has these parts:

Part Descriptionobject Optional. An object expression that evaluates to an object in the Applies To

list. Ifobjectis omitted, the form with the focus is assumed to be object.Menuname Required. The name of the pop-up menu to be displayed. The specified

menu must have at least one submenu.Flags Optional. A value or constant that specifies the location and behavior of a

pop-up menu, described as follows:

Constant (location) Value DescriptionvbPopupMenuLeftAlign 0 (Default) The left side of the

pop-up menu is located atx.vbPopupMenuCenterAlign 4 The pop-up menu is

centered atx.vbPopupMenuRightAlign 8 The right side of the pop-up

menu is located atx.

Constant (behavior) Value DescriptionvbPopupMenuLeftButton 0 (Default) An item on the pop-

up menu reacts to a mouseclick only when you use theleft mouse button.

vbPopupMenuRightButton 2 An item on the pop-up menureacts to a mouse click whenyou use either the right orthe left mouse button.


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Note: To specify both a "location" constant and a "behavior" constant, addthe two values together. For example:

PopupMenu MyMenu, vbPopupMenuRightAlign +vbPopupMenuRightButton

X Optional. Specifies the x-coordinate where the pop-up menu is displayed. Ifomitted, the mouse coordinate is used.

Y Optional. Specifies the y-coordinate where the pop-up menu is displayed. Ifomitted, the mouse coordinate is used.

boldcommand Optional. Specifies the name of a menu control in the pop-up menu todisplay its caption in bold text. If omitted, no controls in the pop-up menuappear in bold.

5. Code the mnuBold_Click event as shown below. Note that the Checked property of the menu item isused. When set to True, this causes a checkmark to appear to the left of the menu item. TheChecked property is typically used as a toggle.

Private Sub mnuBold_Click()

If mnuBold.Checked Then

lblTestText.FontBold = False

mnuBold.Checked = False

Else

lblTestText.FontBold = True

mnuBold.Checked = True

End If

End Sub

6. Code the mnuItalic_Click and mnuUnderline_Click events in a similar fashion as shown below.


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Private Sub mnuItalic_Click()

If mnuItalic.Checked Then

lblTestText.FontItalic = False

mnuItalic.Checked = False

Else

lblTestText.FontItalic = True

mnuItalic.Checked = True

End If

End Sub

Private Sub mnuUnderline_Click()

If mnuUnderline.Checked Then

lblTestText.FontUnderline = False

mnuUnderline.Checked = False

Else

lblTestText.FontUnderline = True

mnuUnderline.Checked = True

End If

End Sub

7. Run the program and check out the various options you have coded.


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8. Save the program and exit VB.

Download the project files for this examplehere.

NOTES:

If desired, you can have both a "regular" menu and as many pop-up menus as you want on the sameform. Any top-level menu that has its Visible box checked in the Menu Editor will appear at the top of theform in the menu bar you create. Any top-level menu that has its Visible box unchecked in the MenuEditor will NOT appear at the top of the form in the menu bar, but can be used as a pop-up menu invokedwith the PopupMenu method.

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Comments

Fri, 09/10/2010 - 06:57Anonymous (not verified)

How to change font size of menu

How to change font size of menu

reply

Sat, 08/14/2010 - 09:29 murtaza (not verified)

vb 6.0 problem
http://www.vb6.us/files/VBPrograms/Menus/PopupDemo.ziphttp://www.vb6.us/files/VBPrograms/Menus/PopupDemo.ziphttp://www.vb6.us/files/VBPrograms/Menus/PopupDemo.ziphttp://www.vb6.us/printable/node/296http://www.vb6.us/tutorials/working-menus-vb6#comment-4697http://www.vb6.us/comment/reply/296/4697http://www.vb6.us/tutorials/working-menus-vb6#comment-4509http://www.vb6.us/tutorials/working-menus-vb6#comment-4509http://www.vb6.us/comment/reply/296/4697http://www.vb6.us/tutorials/working-menus-vb6#comment-4697http://www.vb6.us/printable/node/296http://www.vb6.us/files/VBPrograms/Menus/PopupDemo.zip


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hey guys out there. i am preparing an application where i need to make menus. i know i can

display menus through menu editor, and also i can open 'open dialogue box' through

commondialoguebox. but i don't no how to open a file. plz guide me..

reply

Fri, 08/20/2010 - 10:08fifth (not verified)

Resolve the problem of murtaza

go here this link:

http://www.vb6.us/tutorials/common-dialogs-vb-tutorial

there's a Open File tutorial using a common dailogs!

reply

Thu, 07/29/2010 - 05:43 shanavas (not verified)

Effective Tutorial

This is very much helpful for beginners

reply

Wed, 07/21/2010 - 10:27vaishnavi kulkarni (not verified)

query

gdf i have a query about this chapter is that if i want to create the menu in other indian language

like Marathi,Kannada then what are the steps to craete this or how i will get this type of menues.

reply

Sun, 07/11/2010 - 01:50 Anonymous (not verified)

thanks for nice tutorial...

thanks for nice tutorial...

reply

Sat, 06/19/2010 - 10:15 HaroldMcFaggiton (not verified)

yeah
http://www.vb6.us/comment/reply/296/4509http://www.vb6.us/tutorials/working-menus-vb6#comment-4571http://www.vb6.us/comment/reply/296/4571http://www.vb6.us/tutorials/working-menus-vb6#comment-4414http://www.vb6.us/comment/reply/296/4414http://www.vb6.us/tutorials/working-menus-vb6#comment-4375http://www.vb6.us/comment/reply/296/4375http://www.vb6.us/tutorials/working-menus-vb6#comment-4318http://www.vb6.us/comment/reply/296/4318http://www.vb6.us/tutorials/working-menus-vb6#comment-4209http://www.vb6.us/tutorials/working-menus-vb6#comment-4209http://www.vb6.us/comment/reply/296/4318http://www.vb6.us/tutorials/working-menus-vb6#comment-4318http://www.vb6.us/comment/reply/296/4375http://www.vb6.us/tutorials/working-menus-vb6#comment-4375http://www.vb6.us/comment/reply/296/4414http://www.vb6.us/tutorials/working-menus-vb6#comment-4414http://www.vb6.us/comment/reply/296/4571http://www.vb6.us/tutorials/working-menus-vb6#comment-4571http://www.vb6.us/comment/reply/296/4509


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Thanks for theh tut!

Is there an way to add it to an textbox wihout you'll get the standard context box with :

paste,check spelling and so...

thx

reply

Wed, 06/02/2010 - 23:44KittyA (not verified)

Popup Menu with MSHFlexGrid?

Hello All,

Is it possible to use this same code to bind the popup menu with a MSHFlexGrid?? It does not

seem to work!!! Is there anything else that i need to specify when trying to invoke the popupmenu with a MSHFlexGrid??

Please help me with this

Many thanks for an early reply
http://www.vb6.us/comment/reply/296/4209http://www.vb6.us/tutorials/working-menus-vb6#comment-4132http://www.vb6.us/tutorials/working-menus-vb6#comment-4132http://www.vb6.us/comment/reply/296/4209


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MDI Overview

This document introduces you to the concept of Multiple Document Interface (MDI) and how to create menus

within an MDI application. You will learn to create an MDI application in Microsoft Visual Studio .NET and learn

why you might want to use this type of interface. You will learn about child forms that are contained within the

MDI application, and learn to create shortcut, or context-sensitive, menus.

MDI is a popular interface because it allows you to have multiple documents (or forms) open in one application.

Examples of MDI applications include Microsoft Word, Microsoft Excel, Microsoft PowerPoint, and even the

Visual Studio integrated development environment itself. Each application consists of one (or more) parent

windows, each containing an MDI client areathe area where the child forms (or documents) will be displayed.

Code you write displays as many instances of each of the child forms that you want displayed, and each child

form can only be displayed within the confines of the parent windowthis means you can't drag the child

forms outside the MDI container. Figure 1 shows a basic MDI application in use.

Figure 1. Use MDI to open multiple windows and have them all contained within the parent area

Single Document Interface

Don't be misled: MDI is only one of several possible paradigms for creating a user interface. You can also create

applications that display just a single form. They're easier to create, in fact. Those applications are called Single

Document Interface (SDI) applications. Microsoft Windows Notepad is an SDI application, and you can only

open a single document at a time. (If you want multiple documents open, you simply run Notepad multipletimes.) You are under no obligation to create your applications using the MDI paradigm. Even if you have

multiple forms in your project, you can simply have each one as a stand-alone form, not contained by any

parent form.

Uses of MDI

You'll use MDI most often in applications where the user might like to have multiple forms or documents open

concurrently. Word processing applications (like Microsoft Word), spreadsheet applications (like Microsoft


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Excel), and project manager applications (like Microsoft Project) are all good candidates for MDI applications.

MDI is also handy when you have a large application, and you want to provide a simple mechanism for closing

all the child forms when the user exits the application.

Creating an MDI Parent Form

To create an MDI parent form, you can simply take one of your existing forms and set its IsMDIContainer

property to True. This form will now be able to contain other forms as child forms. You may have one or many

container forms within your application.

Tip Note the difference here between Visual Studio .NET and Microsoft Visual Basic 6.0 behavior. In Visual

Basic 6.0, you could only have a single MDI parent form per application, and you had to use the Project menu

to add that one special form. In Visual Studio .NET, you can turn any form into an MDI parent form by simply

modifying a property, and you can have as many MDI parent forms as you require within the same project.

You may have as many different child forms (the forms that remain contained within the parent form) as you

want in your project. A child form is nothing more than a regular form for which you dynamically set the

MdiParent property to refer to the MDI container form.

Note The user interface objects you've designed within the Visual Studio environment are really templates for

forms. That is, they don't actually become real Form objects until you instantiate them at run time. Therefore,

your project can contain as many different templates for MDI child forms as you like. You can instantiate and

then show as many instances of as many different templates as you need, while your applications are running.

Run-time Features of MDI Child Forms

At run time, the MDI parent form and the MDI child forms take on special features:

All child forms are displayed within the MDI parent's clientarea. The client area is the area below the

MDI parent's title bar, any menus, and any tool bars. Child forms can be moved and sized only within the MDI parent's client area.

Child forms can be minimized and their icon will be displayed within the parent's client area.

Child forms can be maximized within the parent's client area and the caption of the child form is

appended to the caption of the MDI form.

Windows automatically gives child forms that have their FormBorderStyle property set to a sizable

border a default size. This size is based on the size of the MDI parent's client area. You can override this

by setting the FormBorderStyle property of the child form to any of the fixed type of borders.

Child forms cannot be displayed modally.

The MDI form can be minimized and only one icon will be displayed on the desktop representing the

MDI form and all of its children.

If the MDI form is unloaded, all of the loaded children will also be unloaded.

Note The client area includes any usable area on the MDI form minus any toolbars or status bars that you may

have added to the MDI form.

Create an MDI Project


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In this section, you will walk through the steps of creating a simple MDI application using Visual Studio .NET. To

do this, you will create a new form that will be the MDI parent form. You will add some menus to this new form,

and then you will load the product form from a menu as a child form.

Create the MDI Parent Form

To create the MDI parent form

1. Open Visual Studio .NET

2. Create a new Windows application project.

3. Set the name of the project to MDI.sln.

4. Rename the form that is created automatically to frmMain.vb.

5. With the frmMain selected, set the form's IsMdiContainer property to True.

6. Set the WindowState property to Maximized.

That's all there is to it: you've created an MDI parent form.

Creating MenusYour main form will require menus so that you can perform actions such as opening child forms, copying and

pasting data, and arranging windows. Visual Studio .NET includes a new menu designer that makes creating

and modifying menus a snap.

To add menus to your MDI parent form

1. Double-click the MainMenu tool in the Toolbox window to add a new object named MainMenu1 to the

form tray.

Note Unlike the form designer in Visual Basic 6.0, the Visual Studio .NET form designer places

controls that don't have a user interface at run time into a special area on the form designer: the form"tray". They're out of the way, and don't get buried underneath other controls. This is a real

improvement!

2. At the top of the MDI parent form, click the box with Type Here in it and type &File.

Tip Just as in Visual Basic 6.0, inserting an ampersand (&) into a menu caption displays the caption

with an underscore under the following letter. Pressing Alt+ acts as a hotkey, activating

the menu item. One thing to note: if you're using Windows 2000 or later, it's possible that the hotkeys

won't show up underlined until you press the Alt key. This setting is buried in the Display applet within

Control Panel. In the Display Properties dialog box, check the Effects page: the Hide keyboard

navigation indicators until I use the Alt key option controls this behavior.

3. Press Enter to move to the next menu item and type &Products.

4. Press Enter to move to the next menu item and type a hyphen (-).

Tip Rather than using the "-" to indicate a divider in the menu, you can insert the next menu item

(Exit, in this case), and then right-click the new item. Select "Insert Separator" from the context menu,

and Visual Studio .NET will insert a separator above the current item for you.


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5. Press Enter and type E&xit.

You have now created the first drop-down menu on your main form. You should have something that looks like

Figure 2.

Figure 2. The menu designer allows you to type your menu structure in a WYSIWYG fashion

To the right of the File menu and at the same level, you'll see another small box with the text, Type Here. Clickit and type the following menu items by pressing Enter after each one.

&Edit

Cu&t

&Copy

&Paste

Once more to the right of the Edit menu and at the same level, add the following menu items in the same

manner.

&Window

&Cascade Tile &Horizontal

Tile &Vertical

&Arrange Icons

Creating Names for Each Menu

After creating all the menu items, you'll need to set the Name property for each. (Because you'll refer to the

name of each menu item from any code you write concerning that menu item, it's important to choose a name

you can understand from within your code.) Instead of clicking each menu item one at a time and then moving

over to the Properties window to set the Name property, Visual Studio provides a shortcut: Right-click an item

in the menu, then select Edit Names from the context menu. Now you can simply click each menu item and set

the name property directly on each menu. This is certainly quicker than using the Properties window toaccomplish the same task.

Use the following names for your menu items:

mnuFile

mnuFProducts

mnuFExit


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mnuEdit

mnuECut

mnuECopy

mnuEPaste

mnuWindow

mnuWCasade

mnuWHorizontal mnuWVertical

mnuWArrange

Test out your application: Press F5 and you should see your main MDI window appear with your menu system

in place.

Display a Child Form

To add the code that displays the child form, frmProducts, make sure the main form is open in Design view, and

on the File menu, double-click Products. Visual Studio .NET will create the stub of the menu item's Click event

handler for you. Modify the procedure so that it looks like the following:

CopyPrivate Sub mnuFProducts_Click( _

ByVal sender As System.Object, _ByVal e As System.EventArgs) Handles mnuFProducts.Click

Dim frm As New frmProducts()

frm.MdiParent = Me

frm.Show()

End Sub

This code declares a variable, frm, which refers to a new instance of the frmProducts form in the sample project.Then, you set the MdiParent property of the new form, indicating that its parent should be the current form

(using the Me keyword). Finally, the code calls the Show method of the child form, making it appear on the

screen.

Some interesting things to note:

Me is a built-in keyword in Visual Basic .NETjust as in Visual Basic 6.0, this keyword refers to the class

whose code is currently running. In this case, that's the MDI parent form, whose menu item you just

clicked.

You don't have to set the MdiParent property of the new child form. If you don't, the form will simply

load as a new normal form, outside the MDI parent. As a matter of fact, you can set the MDI parent to

be a different MDI container if you like. If you don't call the Show method, the child form won't ever display.

Differentiating Between Child Windows

You'll note that each instance of the Products form looks identical. You'll most likely need some way to

differentiate the windows. One alternative is to modify the caption of the window as you load each instance. In

the sample, you can create a static variable to contain a counter, increment that variable each time you open a

form, and then assign that value into the Text property of the form.


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To uniquely identify each child form

1. Modify the mnuFProducts_Click procedure so that it looks like this:

Copy

Private Sub mnuFProducts_Click( _

ByVal sender As System.Object, _

ByVal e As System.EventArgs) _Handles mnuFProducts.Click

Dim frm As frmProductsStatic intCount As Integer

frm = New frmProducts()

' Increment the caption counter.intCount += 1

' Set the caption to be unique.

frm.Text = frm.Text & " " & intCount.ToString()

frm.MdiParent = Me

frm.Show()End Sub

2. Run the project, create a few Products forms, and note that the caption of each form includes a

different number.

Note What's that Statickeyword? Using Static, rather than Dim, to declare a variable inside a

procedure creates a variable that maintains its value from one invocation of the procedure to the next.

When you declare a variable using Dim, that variable gets reinitialized each time the procedure is

called. When you use Static, the variable maintains its value. That's what you want, in this case

you

want intCount to maintain its value, so that it continues to increment each time you create a new

instance of frmProducts.

Child Menus in MDI Applications

What if a child form has its own set of menus? How do those menus interact with the menus of the parent

form? In previous versions of Visual Basic you really didn't have much control over the behaviorthe menus of

the currently active child simply replaced the menus of its parent. In Visual Studio .NET, however, you can

control how the menus interact, using the MergeOrder and MergeType properties of the individual menu

items.

The MergeOrder propertycontrols the relative position of the menu item when its menu structure gets merged

with the parent form's menus. The default value for this property is 0, indicating that this menu item will be

added at the end of the existing menu items. The MergeType property controls how the menu item behaves

when it has the same merge order as another menu item being merged. Table 1 shows a list of the possible

values you can assign to the MergeType property.

Table 1. The MergeType property allows you to specify what happens when menu items merge


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Value Description

Add The MenuItem is added to the collection of existing MenuItem objects in a merged menu.

(Default)

MergeItems All submenu items of this MenuItem are merged with those of existing MenuItem objects

at the same position in a merged menu.

Remove The MenuItem is not included in a merged menu.

Replace The MenuItem replaces an existing MenuItem at the same position in a merged menu.

By default, a menu item's MergeOrder property is set to 0. The MergeType property is set to Add by default.

This means that if you create a child form with a menu on it, the menu will be added at the end of the main

menu. Consider Figure 3, which shows a child form called from the parent form's main menu. This form has a

Maintenance menu on it (and the parent form does not). All of the items on the parent's main menu have their

MergeOrder properties set to 0 and this menu's MergeOrder property is set to 0, so this menu will be added

at the end of the main menu on the MDI parent form.

Figure 3. A child form that has menus will by default be added to the end of the main menu

To create the form in Figure 3

1. On the Project menu, click Add Windows Form.

2. Set the new form's name to frmChildWithMenus.vb.

3. Add a MainMenu control to this form.

4. Set the Name property for the MainMenu control to mnuMainMaint.

5. Add the following menus as shown in Table 2.

Table 2. Windows Form menus

Menu Name

&Maintenance mnuMaint

&Suppliers mnuMSuppliers

&Categories mnuMCategories

If you were to call this form exactly like you did the Products form in the previous section you will see that your

main form looks like Figure 4. You can see that by default, the menu is added to the end of this form.


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Figure 4. Menus are added to the end of the main menu by default

Call this form by adding a new menu item under the File menu:

1. Open frmMain.vb in Design view.

2. Click on the separator after the Products menu item and press the Insert key to add a new menu item.

3. Type Child form with Menus as the text of this new menu item.

4. Set the Name property of this new menu item to mnuFChild.

5. Double click this new menu item and modify its Click event handler so that it looks like this:

Copy

Private Sub mnuFChildMenus_Click( _ByVal sender As System.Object, _ByVal e As System.EventArgs) _Handles mnuFChildMenus.Click

Dim frm As New frmChildWithMenus()frm.MdiParent = Mefrm.Show()

End Sub

Note If you wish to merge the Maintenance menu in between the Edit and Window menus, you

could set the MergeOrder property on the Edit menu item to 1, and the MergeOrder property on the

Window menu to a 2. Then on the Maintenance menu item on frmChildWithMenus, set the

MergeOrder property to 1 and leave the MergeType with its default value, Add. Taking these steps

will add the Maintenance menu after the menu on the main form with the same MergeOrder numberas it has (that is, after the Edit menu, but before the Window menu).

Working with MDI Child Forms

If you have multiple child forms open, you may want to have them arrange themselves, much as you can do in

Word or Excel, choosing options under the Window menu. Table 3 lists the available options when arranging

child windows.


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Table 3. Choose one of these values when arranging child windows

Menu Item Enumerated Value

Tile Horizontal MdlLayout.TileHorizontal

Tile Vertical MdiLayout.TileVertical

Cascade MdiLayout.Cascade

Arrange Icons MdiLayout.ArrangeIcons

Add some menus to your main form for each of these options:


2. On the Window menu, double-click Cascade.

3. For the Cascade menu item, modify the Click event handler so that it looks like the following:

Copy

Private Sub mnuWCascade_Click( _ByVal sender As System.Object, _

ByVal e As System.EventArgs) _Handles mnuWCascade.Click

Me.LayoutMdi(MdiLayout.Cascade)End Sub

On the Window menu, double-click each menu item and add the appropriate code.

Tip The LayoutMDI method replaces the Arrange method you may have used in Visual Basic 6.0.

What If There's No Active Child Form?

If there's no active child form, attempting to work with the ActiveMdiChild property of the parent form will

trigger a run-time error. To avoid this situation, you can check the value of the property in the Click event

handler for the Window menu item, and enable or disable the Center Child Form menu item accordingly. To

add this feature, follow these steps:

1. With frmMain open in Design view, press F7 to edit the form's code module.

2. Select mnuWindow from the Class Name combo box (the list on the top left of the editor window),

and then select Select from the Method Name combo box (the list on the right).

3. Modify the Select event handler, so that it looks like this:

Copy

Private Sub mnuWindow_Popup( _

ByVal sender As Object, _ByVal e As System.EventArgs) _

Handles mnuWindow.PopupmnuWCenterChild.Enabled = _

Not (Me.ActiveMdiChild Is Nothing)


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End Sub

4. 4.Run the project, and verify that if you have child windows displayed, the Center Child Form menu

item is enabled. If there isn't a child form open, verify that the menu item is disabled.

How does this work? Here are some things to consider:

The Popup event occurs when you select a menu item that includes sub-items. (You can't use the Click

event, since that event doesn't occur for menu items that contain sub-items.)

The Is operator allows you to compare values to the built-in value Nothing. In this case, the

ActiveMdiChild property returns this special value if it doesn't refer to a form, and you must use the Is

operator to check for this. (The = operator checks values for equality: the Is operator checks references

to objects for equality.)

The syntax of the procedure may be confusing. The value in parentheses (Me, ActiveChild, Is,

Nothing) returns a Boolean value: it's either True or False. The Not operator toggles the returned

value to be the opposite Boolean value. The whole line of code assigns the return value from the

expression in parentheses to the Enabled property of the menu item. In this case, if it's not true that

the ActiveChild is Nothing, you'll enable the menu item. If it's True, you'll disable the menu item.

Tracking Child Windows

Visual Basic .NET will keep track of all child forms that you create, and it's easy to create a window list menu to

manage the child windows. If you wish to see a list of all of the child forms and be able to give a specific child

form focus, follow these steps:

1. Load frmMain in Design view.

2. Select frmMain's Window menu.

3. In the Properties window, set the MdiList to True.

4. Run the project, open a couple of Products forms, and then click the Window drop-down menu. You

should see each instance of the Product form that you opened displayed in the window list.

Creating Shortcut Menus

In most modern Windows applications, you can click the right mouse button and see a context-sensitive, or

shortcut (pop-up), menu. These menus give you the ability to perform actions based on the current context

that is, changing depending on the current situation.

Visual Studio provides the ContextMenu control, making it just as easy to create context menus as it was to

create main menus. Once you've dropped one of these controls on your form (it will appear in the tray area, just

like the MainMenu control did), you can edit the menu items to be displayed by this context menu.

Note The design of your context menu won't display on the form until you've clicked the ContextMenucontrol. This makes it possible for one form to contain both MainMenu and ContextMenu controls.

Tip You can place as many ContextMenu controls as you need on your forms.

To add a context menu to the Products form:

1. Open frmProducts in Design view.

2. In the Toolbox, find the ContextMenu control.


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3. Double-click this control to add it to the tray area of the form.

4. Click the ContextMenu control to give it focus.

5. Change the Name property to cmnuProdID.

6. Add the menu items (shown in Table 4) to this control, and set the Name properties as shown. When

you add to a context menu, you start with the first menu item under the top-level menu. Figure 5

shows the finished context menu.

Table 4. Context menu items

Menu Name

&Lookup mnuPLookUp

&Copy mnuPCopy

&Paste mnuPPaste

Figure 5. When adding items to the ContextMenu control, create a top-level item that won't

ever be displayed as the parent for your items

7. Click the Product ID text box.

8. In the Properties window, set the ContextMenu property to the ContextMenu control you just

created, cmnuProdID.

9. Run the project. On the File menu, click Products to create a child form, and righ-click on the Product

ID text box to see the context menu appear.

If you were completing this form, you could now add code to respond to the Click events on each of these

menus.

Manipulating Menus at Run Time

You may need to modify the behavior of menu items while your application is running. In this section, you'll see

how to check and uncheck, and add and remove menu items programmatically.

To set up for the following sections, you will need to add three new menu items under the File menu on your

MDI form.


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2. Click the File menu to display its sub-items.

3. Add three menu items, as described in Table 5.

Table 5. File menu items

Menu Name

&Add Menus mnuFAddMenus

&Remove Menus mnuFRemoveMenus

&Add &New Menu mnuFAddNew

Checking and Unchecking Menu Items

Visually selecting a menu item programmatically is easy: simply set the menu item's Checked property to True

or False, as necessary. For example, you might want to indicate that you've added new menu items by adding a

check to the Add Menus item, and remove it once you've removed the items. You'll add and remove the menu

items in the next section, but for now, add and remove the check by following these steps:

1. On the File menu, double-click Add Menus to view the Click event procedure.

2. Modify the event procedure, so that it looks like this:

Copy

Private Sub mnuFAddMenus_Click( _

ByVal sender As System.Object, _ByVal e As System.EventArgs) _

Handles mnuFAddMenus.Click

If Not mnuFAddMenus.Checked ThenmnuFAddMenus.Checked = True

End If

End Sub

3. To repeat the previous two steps, on the File menu, double-click Remove Menus and modify its Click

event procedure so that it looks like this:

Copy

Private Sub mnuFRemoveMenus_Click( _


ByVal e As System.EventArgs) _Handles mnuFRemoveMenus.Click

If mnuFAddMenus.Checked Then

mnuFAddMenus.Checked = FalseEnd If

End Sub

4. Run the project, and on the File menu, double-click Add Menus. Verify that you see a check next to

the item. To repeat, on the File menu, click Remove Menus to verify that the check has been removed.


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Adding and Removing Menus

Windows Forms allows you to add and remove menus programmatically at run time. Using the Add and

Remove (or RemoveAt) methods of the MenuItems collection, you can create new menus at run time, and

delete any menu items.

Note In Visual Basic 6.0, you could only delete menu items that you created dynamically, at run time. That is,

you couldn't delete static menu items. In Visual Studio .NET, you can delete any menu item.

Adding Menus ProgrammaticallyTo add a menu item, call the Add method of a particular menu item. For example, you might want to add two

new menu items on the File menu. To do this, follow these steps:

1. On the on the File menu, double-click Add Menus to view its Click event handler.

2. Modify the event procedure so that it looks like this:

Copy

Private Sub mnuFAddMenus_Click( _

ByVal sender As System.Object, _ByVal e As System.EventArgs) _

Handles mnuFAddMenus.Click

If Not mnuFAddMenus.Checked ThenmnuFAddMenus.Checked = True

' Adds these menus to the end of the File menuWith mnuFile.MenuItems

.Add("New Menu 1")

.Add("New Menu 2")

End With

End IfEnd Sub

Each menu item contained within the MainMenu (or ContextMenu) control is itself a MenuItem object, and

just as with any other object, you refer to the menu items using the Name property you assigned to each. If a

menu item contains other menu items (as each top-level menu item does), you can use its MenuItems property

to refer to the collection of menu items it contains. In this case, you called the Add method of a MenuItem

object (mnuFile) to add menu items to the collection of items. (In this example, mnuFile was the name you

assigned to the File menu item.)

Removing Menus ProgrammaticallyTo remove menu items programmatically, you can either call the MenuItem collection's Remove or RemoveAt

method. Remove requires you to provide a MenuItem object; if you instead want to remove items by their

position within the menu, call the RemoveAt method.

In this example, the simplest way to remove the menu items you created in the previous steps is to specify their

position within the menu. You'll call the RemoveAt method to do the work. Because menu items are numbered

starting at 0 (as are all collections and arrays in Visual Basic .NET), you need to take that into account when

removing menu items.


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To handle removing the two menu items you've just added, modify the Click event procedure for the Remove

Menus items on the File menu, so that the procedure looks like this:

CopyPrivate Sub mnuFRemoveMenus_Click( _


ByVal e As System.EventArgs) _Handles mnuFRemoveMenus.Click

If mnuFAddMenus.Checked Then

With mnuFile.MenuItems

' Remove the last two items.RemoveAt(.Count - 1)

.RemoveAt(.Count - 1)End WithmnuFAddMenus.Checked = False

End If

End Sub

Run the project to verify that choosing the Add and Remove Menus menu items correctly adds and removes

the two extra items.

Using Menu Groups

When you add a check to a menu item, you're indicating the state of that menu itemit's either selected, or it's

not. Normal checked menus work individually, and are independent of other menu items.

You may have a need to treat a group of menu items as a dependent set. In this case, selecting one item from

the group forces all the other items in the group to be deselected. Although Visual Studio .NET doesn't provide

a way to make this happen for you, it does supply the RadioCheckproperty of menu items that at least

provides a visual indication. Rather than seeing a normal check, menu items with their RadioCheckproperty set

to True display a dot when they're selected. It's still up to your code to deselect all the other items in your

menu group, once the user selects a menu item.

To demonstrate this behavior, modify properties and add code so that the four window management menu

items (Cascade, Tile Horizontal, Tile Vertical, Arrange Icons) work as a group. To do that, follow these steps:

1. With frmMain open in Design view, select the Window>Center Child Form menu item.

2. Right-click, and on the shortcut menu, click Insert Separator, which inserts a separator item above the

selected item.

3. Click on the Window>Cascade menu item, then at the same time, press Ctrl and click the other four

window management items on the menu, selecting all four.

4. In the Properties window, set the RadioCheckproperty for the four selected menu items to True.

5. Add the following procedure to the frmMain class:

Copy

Private Sub RadioCheck_Click( _

ByVal sender As System.Object, _ByVal e As System.EventArgs) _Handles mnuWArrange.Click, mnuWCascade.Click, _mnuWHorizontal.Click, mnuWVertical.Click


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mnuWArrange.Checked = False

mnuWCascade.Checked = FalsemnuWHorizontal.Checked = FalsemnuWVertical.Checked = FalseCType(sender, MenuItem).Checked = True

End Sub

6. Run the project, create some Product forms, and use the Window menu items to arrange the children.

As you use the Cascade, Tile Horizontal, and other menu items, you should see a circle next to the

most recently selected item. Figure 6 shows the results of adding this new feature.

Figure 6. Setting a menu item's RadioCheck property to True shows a dot, rather than a check,

next to selected items

How Did the Code Work?

It may seem odd that you managed to add new functionality to four menu items without modifying their event

procedures at all. This example took advantage of a new feature in Visual Basic .NETyou can hook up as many

event handlers to a specific event as you need, using the Handles clause on a procedure. Here, you provided a

new procedure (RadioCheck_Click) that handles Click events for each of the four menu items you want to have

work together.

Here are the important issues:

The procedure you want to call must match the procedure signature of the standard Click event for

menu items. That is, it must receive two parameters (one as System.Object, the other as

System.EventArgs) and return nothing at all. (It must be a Sub, in other words.)


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