How to Implement a Bitmap Within a Visual Basic Menu

ID Number: Q71281

1.00

WINDOWS

Summary:

No command provided by the Visual Basic language can add a bitmap to

the menu system. However, you can call several Windows API functions

to place a bitmap within the menu system of a Visual Basic program. You

may also change the default check mark displayed.

This information applies to Microsoft Visual Basic programming system

version 1.0 for Windows.

More Information:

There are several Windows API functions you can call that will display

a bitmap instead of text in the menu system.

Below is a list of the required Windows API functions:

- GetMenu% (hwnd%)

hwnd% - Identifies the window whose menu is to be examined

Returns: Handle to the menu

- GetSubMenu% (hMenu%, nPos%)

hMenu% - Identifies the menu

nPos% - Specifies the position (zero-based) in the

given menu of the pop-up menu

Returns: Handle to the given pop-up menu

- GetMenuItemID% (hMenu%, nPos%)

hMenu% - Identifies the handle to the pop-up menu that

contains the item whose ID is being retrieved

nPos% - Specifies the position (zero-based) of the menu

whose ID is being retrieved

Returns: The item ID for the specified item in the pop-

up menu

- ModifyMenu% (hMenu%, nPos%, wFlags%, wIDNewItem%, lpNewItem&)

hMenu% - Identifies the handle to the pop-up menu that

contains the item whose ID is being retrieved

nPos% - Specifies the menu item to be changed. The

interpretation of the nPos parameter depends

on the wFlags parameter.

wFlags% - BF_BITMAP = &H4

wIDNewItem% - Specifies the command ID of the modified menu item

lpNewItem& - 32-bit handle to the bitmap

Returns: TRUE (-1) if successful, FALSE (0) if unsuccessful

- SetMenuItemBitmaps% (hMenu%, nPos%, Flags%, hBitmapUnchecked%,

hBitmapChecked%)

hMenu% - Identifies menu to be changed

nPos% - Command ID of the menu item

wFlags% - &H0

hBitmapUnchecked% - Handle to "unchecked" bitmap.

hBitmapChecked%) - Handle to the "check" bitmap.

Returns: TRUE (-1) if successful, FALSE (0) if unsuccessful.

There are two different ways to implement bitmaps within Visual Basic:

the first method is to use static bitmaps; the other method is to use

dynamic bitmaps.

A static bitmap is fixed and does not change during the execution of

the program (such as when it is taken from an unchanging .BMP file). A

dynamic bitmap changes during execution of your program. You may

change dynamic bitmap attributes such as color, size, and text. The

sample code below describes how to create both types of menus.

Define a menu system using the Menu Design window. Create a menu

system such as the following:

Caption CtlName Indented Index

------- ------- -------- -----

BitMenu TopMenu No

Sub Menu0 SubMenu Once 0

Sub Menu1 SubMenu Once 1

Sub Menu2 SubMenu Once 2

Create a picture control array with three bitmaps by creating three

picture controls with the same CtlName using the Properties list box.

CtlName Caption Index FontSize

------- ------- ----- --------

Picture1 0 N/A

Picture1 1 N/A

Picture1 2 N/A

Picture2 N/A N/A 'check BMP

Picture3 0 'set Picture3's FontSize all

different

Picture3 1 9.75

Picture3 2 18

Command1 Static

Command2 Dynamic

For each control index of Picture1, add a valid bitmap to the Picture

property. Because these bitmaps will be displayed in the menu, you

should use smaller bitmaps. Add a bitmap to the Picture2 Picture

property that you want to be your check mark when you select a menu

option.

Both types of bitmap implementations will need to have the following

declarations in the declaration or global section of your code:

Declare Function GetMenu% Lib "user" (ByVal hwnd%)

Declare Function GetSubMenu% Lib "user" (ByVal hMenu%, ByVal nPos%)

Declare Function GetMenuItemID% Lib "user" (ByVal hMenu%, ByVal nPos%)

Declare Function ModifyMenu% Lib "user"

(ByVal hMenu%,

ByVal nPosition%,

ByVal wFlags%,

ByVal wIDNewItem%,

ByVal lpNewItem&)

Declare Function SetMenuItemBitmaps% Lib "user"

(ByVal hMenu%,

ByVal nPosition%,

ByVal wFlags%,

ByVal hBitmapUnchecked%,

ByVal BitmapChecked%)

' NOTE: Each Declare statement above must be on just one line.

Const MF_BITMAP = &H4

Const CLR_MENUBAR = &H80000004 ' Defined for dynamic bitmaps only.

Const TRUE = -1, FALSE = 0

Const Number_of_Menu_Selections = 3

The following Sub will also need to be defined to handle the actual

redefinition of the "check" bitmap:

Sub SubMenu_Click (Index As Integer)

' Uncheck presently checked item, check new item, store

' index

Static LastSelection%

SubMenu(LastSelection%).Checked = FALSE

SubMenu(Index).Checked = TRUE

LastSelection% = Index

End Sub

Sub Command1_Click ()

'* example to create a static bitmap menu

hMenu% = GetMenu(hWnd)

hSubMenu% = GetSubMenu(hMenu%, 0)

For i% = 0 To Number_of_Menu_Selections - 1

menuId% = GetMenuItemID(hSubMenu%, i%)

x% = ModifyMenu(hMenu%, menuId%, MF_BITMAP, menuId%,

CLng(picture1(i%).Picture))

x% = SetMenuItemBitmaps(hMenu%, menuId%, 0, 0,

CLng(picture2.Picture))

Next i%

End Sub

'This code sample will change the actual menu bitmaps size,

'font size, color, and caption. Run the application and

'select the BitMenu and view the selections. Then click on

'the form and revisit the BitMenu.

'---------------------------------------------------------

Sub Command2_Click ()

'* Example to create a dynamic menu system

hMenu% = GetMenu(hWnd)

hSubMenu% = GetSubMenu(hMenu%, 0)

For i% = 0 To Number_of_Menu_Selections - 1

'* Place some text into the menu.

SubMenu(i%).Caption = Picture3(i%).FontName +

Str$(Picture3(i%).FontSize) + " Pnt"

'* 1. Must be AutoRedraw for Image().

'* 2. Set Backcolor of Picture control to that of the

'* current system Menu Bar color, so Dynamic bitmaps

'* will appear as normal menu items when menu bar

'* color is changed via the control panel

'* 3. See the bitmaps on screen, this could all be done

'* at design time.

Picture3(i%).AutoRedraw = TRUE

Picture3(i%).BackColor = CLR_MENUBAR

'* You can uncomment this

'* Picture3(i%).Visible = FALSE

'* Set the width and height of the Picture controls

'* based on their corresponding Menu items caption,

'* and the Picture controls Font and FontSize.

'* DoEvents() is necessary to make new dimension

'* values to take affect prior to exiting this Sub.

Picture3(i%).Width = Picture3(i%).TextWidth(SubMenu(i%).Caption)

Picture3(i%).Height = Picture3(i%).TextHeight(SubMenu(i%).Caption)

Picture3(i%).Print SubMenu(i%).Caption

'* - Set picture controls backgroup picture (Bitmap) to

'* its Image.

Picture3(i%).Picture = Picture3(i%).Image

x% = DoEvents()

Next i%

'* Get handle to forms menu.

hMenu% = GetMenu(Form1.hWnd)

'* Get handle to the specific menu in top level menu.

hSubMenu% = GetSubMenu(hMenu%, 0)

For i% = 0 To Number_of_Menu_Selections - 1

'* Get ID of sub menu

menuId% = GetMenuItemID(hSubMenu%, i%)

'* Replace menu text w/bitmap from corresponding picture

'* control

x% = ModifyMenu(hMenu%, menuId%, MF_BITMAP, menuId%,

CLng(Picture3(i%).Picture)) 'append this to previous line

'* Replace bitmap for menu check mark with custom check

'* bitmap

x% = SetMenuItemBitmaps(hMenu%, menuId%, 0, 0, CLng(picture2.Picture))

Next i%

End Sub

Reference(s):

"Programming Windows: the Microsoft Guide to Writing Applications for

Windows 3," Charles Petzold, Microsoft Press, 1990

"Microsoft Windows Software Development Kit: Reference Volume 1,"

version 3.0

WINSDK.HLP file shipped with Microsoft Windows 3.0 SDK

Additional reference words: 1.00