* VB-CODE (3)
Tip 117: Changing a Menu's Shortcut Key at Run Time

July 1, 1995

Abstract
When you use the Menu Editor in Microsoft® Visual Basic®, you can assign a
shortcut or accelerator key to each individual menu entry. This article shows
how you can change this shortcut key at run time within your Visual Basic
application.

Setting Shortcut Keys in Visual Basic Menus
The Microsoft® Visual Basic® Menu Editor lets you easily design a menu system
for your application. When your program is run, the user can click a menu entry
to perform some kind of operation. As an alternative to using the mouse to select
a menu entry, the user can type a keystroke combination such as ALT-S to invoke
the menu selection. These keystroke combinations are called access or accelerator
keys.

After you have designed your menu structure in the Visual Basic Menu Editor, you
may decide to change the access key for a specific menu entry at run time. The
example program below changes the ALT-F access key for the File menu to ALT-E.
To change a menu entry's access key at run time, you need to process the
keystrokes at the form-level. That is, the KeyDown event for the underlying form
will need to be monitored.
The KeyDown event in Visual Basic is triggered each time a user presses a key on
the keyboard. The event is triggered for the control that has the focus. In this
case, the control is the form that the menu is attached to.

The KeyDown event tells you which key or combination of keys was just pressed on
the keyboard. The KeyCode argument gives you a unique number that identifies each
individual key on the keyboard. For example, if the KeyCode value returned is 9,
you know that the TAB key was just pressed.
In the example program below, you use the KeyDown event to determine if the user
pressed the CTRL-E keystroke combination. If CTRL-E was pressed, the program
displays a message box telling you that the File menu item was selected. In all
other cases, the KeyDown event simply ignores the incoming keystrokes.

Example Program
This program shows how to change a menu item's shortcut key from within a Visual
Basic application.

 1. Create a new project in Visual Basic. Form1 is created by default.
 2. Add the following code to the General Declarations section of Form1:

Option Explicit
Dim ShortCut As String * 1

 3. From the Visual Basic Tools menu, click Menu Editor to create a single menu
    item. In the Caption field, type "&File", and in the Name field, type
    "mnuFile". Click OK to create the menu structure and to return to the design
    mode in Visual Basic.
 4. Add the following code to the Form_Load event for Form1:

Private Sub Form_Load()
    Command1.Caption = "Change ShortCut"
    KeyPreview = True
End Sub

 5. Add the following code to the KeyDown event for Form1:

Private Sub Form_KeyDown(KeyCode As Integer, Shift As Integer)
    If Shift And 2 <> 2 Then Exit Sub
    If KeyCode = Asc(ShortCut) Then
        mnuFile_Click
    End If
End Sub

 6. Add the following code to the Click event for mnuFile:

Private Sub mnuFile_Click()
    MsgBox "Menu was selected"
End Sub

 7. Add a Command Button control to Form1. Command1 is created by default. Set
    its Caption property to "Change Item".
 8. Add the following code to the Click event for Command1:

Private Sub Command1_Click()
    ShortCut = "E"
    mnuFile.Caption = "Fil" & "&" & LCase$(ShortCut)
End Sub

Run the example program by pressing F5. Notice the menu at the top of the form.
The menu entry says "File" with the letter F underlined. The letter F is the menu
entry's access key. Click the command button. The menu changes to "File" with the
letter e designated as the access key. Press CTRL-E on the keyboard; a message
box pops up saying that that menu item was just clicked.

Additional References
"Assigning Access Keys and Shortcut Keys." (Development Library,
   Product Documentation, Languages, Visual Basic 4.0 Professional and
   Enterprise Editions, Programmer's Guide.)


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