HOWTO: Use the System Tray Directly from Visual Basic

ID: Q176085


The information in this article applies to:
  • Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, version 6.0
  • Microsoft Visual Basic Control Creation, Learning, Professional, and Enterprise Editions for Windows, version 5.0


SUMMARY

This article demonstrates how to take full advantage of the Windows System Tray using Visual Basic. It places an icon of your choice into the System Tray that will display a ToolTip of your choice when the mouse is rested over it, will restore the application when clicked, and will display a popup menu when right-clicked. This is all possible because of Visual Basic's ability to directly handle callbacks, therefore taking full advantage of the Shell_NotifyIcon function that is exported by Shell32.dll.


MORE INFORMATION

The following example can be added to any Visual Basic Project that has at least one form and a standard module.

Step-by-Step Example:

  1. Add the following code to the declarations section of a standard module in your project:
    
          'user defined type required by Shell_NotifyIcon API call
          Public Type NOTIFYICONDATA
           cbSize As Long
           hwnd As Long
           uId As Long
           uFlags As Long
           uCallBackMessage As Long
           hIcon As Long
           szTip As String * 64
          End Type
    
          'constants required by Shell_NotifyIcon API call:
          Public Const NIM_ADD = &H0
          Public Const NIM_MODIFY = &H1
          Public Const NIM_DELETE = &H2
          Public Const NIF_MESSAGE = &H1
          Public Const NIF_ICON = &H2
          Public Const NIF_TIP = &H4
          Public Const WM_MOUSEMOVE = &H200
          Public Const WM_LBUTTONDOWN = &H201     'Button down
          Public Const WM_LBUTTONUP = &H202       'Button up
          Public Const WM_LBUTTONDBLCLK = &H203   'Double-click
          Public Const WM_RBUTTONDOWN = &H204     'Button down
          Public Const WM_RBUTTONUP = &H205       'Button up
          Public Const WM_RBUTTONDBLCLK = &H206   'Double-click
    
          Public Declare Function SetForegroundWindow Lib "user32" _
          (ByVal hwnd As Long) As Long
          Public Declare Function Shell_NotifyIcon Lib "shell32" _
          Alias "Shell_NotifyIconA" _
          (ByVal dwMessage As Long, pnid As NOTIFYICONDATA) As Boolean
    
          Public nid As NOTIFYICONDATA 


  2. Add the following code to any form in your project that you want to respond to the System Tray Icon for your application:
    
          Private Sub Form_Load()
           'the form must be fully visible before calling Shell_NotifyIcon
           Me.Show
           Me.Refresh
           With nid
            .cbSize = Len(nid)
            .hwnd = Me.hwnd
            .uId = vbNull
            .uFlags = NIF_ICON Or NIF_TIP Or NIF_MESSAGE
            .uCallBackMessage = WM_MOUSEMOVE
            .hIcon = Me.Icon
            .szTip = "Your ToolTip" & vbNullChar
           End With
           Shell_NotifyIcon NIM_ADD, nid
          End Sub
    
          Private Sub Form_MouseMove(Button As Integer, Shift As Integer, X As
       _
             Single, Y As Single)
          'this procedure receives the callbacks from the System Tray icon.
          Dim Result As Long
          Dim msg As Long
           'the value of X will vary depending upon the scalemode setting
           If Me.ScaleMode = vbPixels Then
            msg = X
           Else
            msg = X / Screen.TwipsPerPixelX
           End If
           Select Case msg
            Case WM_LBUTTONUP        '514 restore form window
             Me.WindowState = vbNormal
             Result = SetForegroundWindow(Me.hwnd)
             Me.Show
            Case WM_LBUTTONDBLCLK    '515 restore form window
             Me.WindowState = vbNormal
             Result = SetForegroundWindow(Me.hwnd)
             Me.Show
            Case WM_RBUTTONUP        '517 display popup menu
             Result = SetForegroundWindow(Me.hwnd)
             Me.PopupMenu Me.mPopupSys
           End Select
          End Sub
    
          Private Sub Form_Resize()
           'this is necessary to assure that the minimized window is hidden
           If Me.WindowState = vbMinimized Then Me.Hide
          End Sub
    
          Private Sub Form_Unload(Cancel As Integer)
           'this removes the icon from the system tray
           Shell_NotifyIcon NIM_DELETE, nid
          End Sub
    
          Private Sub mPopExit_Click()
           'called when user clicks the popup menu Exit command
           Unload Me
          End Sub
    
          Private Sub mPopRestore_Click()
           'called when the user clicks the popup menu Restore command
           Me.WindowState = vbNormal
           Result = SetForegroundWindow(Me.hwnd)
           Me.Show
          End Sub 


  3. Make the following Property Settings on the same form to which you added the above code:
    
       Property         Required Setting for System Tray example
       ---------------------------------------------------------------
       Icon           = The icon you want to appear in the system tray.
       Minbutton      = True
       ShownInTaskbar = False 


  4. Add the following Menu items to the same form using the Menu Editor:
    
       Caption      Name          Enabled   Visible   Position
       ---------------------------------------------------------
       &SysTray     mPopupSys      True      False    Main Level
       &Restore     mPopRestore    True      True     Inset one
       &Exit        mPopExit       True      True     Inset one 


You can add additional menu items as needed.

System Tray Flexibility

You can modify the ToolTip that appears over the System Tray icon by changing the following line in the Form_Load procedure:

   .szTip = "Your ToolTip" & vbNullChar 
Replace "Your ToolTip" with the text that you want to appear.

You can modify the Icon that appears in the System Tray by changing the following line in the Form_Load procedure:

   .hIcon = Me.Icon 
Replace Me.Icon with any Icon in your project.

You can change any of the System Trays settings at any time after the use of the NIM_ADD constant by reassigning the values in the nid variable and then using the following variation of the Shell_NotifyIcon API call:

   Shell_NotifyIcon NIM_MODIFY, nid. 
However, if you want a different form to receive the callback, then you will need to delete the current icon first using "Shell_NotifyIcon NIM_Delete, nid" as the NIM_Modify function will not accept a new Hwnd, or you will need to add another Icon to the systray for the new form using "Shell_NotifyIcon NIM_ADD, nid" after refilling the nid type with the new forms Hwnd. You can also declare separate copies of the nid type for each form that you want to display an icon for in the Windows System Tray and change them in each form's activate event using the NIM_DELETE and NIM_ADD sequence.


REFERENCES

For information regarding using the System Tray from Visual Basic 4.0 or earlier, please see the following article in the Microsoft Knowledge Base:

Q149276 HOWTO: Use Icons with the Windows 95 System Tray

Additional query words: Taskbar kbVBp500 kbVBp600 kbdse kbDSupport kbVBp kbVBp400

Keywords : kbGrpVBDB
Version :
Platform : WINDOWS
Issue type : kbhowto


Last Reviewed: January 5, 2000
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