How To Use the System Tray Directly from Visual Basic

 

This article was previously published under Q176085

SUMMARY

This article demonstrates how to take full advantage of the Windows System Tray, or Taskbar Notification Area, using Visual Basic. It places an icon of your choice into the Taskbar Notification Area 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.

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MORE INFORMATION

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

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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, or Notification 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 Dim Result As Long 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 Taskbar Notification Area 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.

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Taskbar Notification Area Flexibility

You can modify the ToolTip that appears over the Notification 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 Taskbar Notification Area 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 Taskbar Notification Area 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.

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REFERENCES

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

149276 (http://support.microsoft.com/kb/149276/EN-US/) How To Use Icons with the Windows 95 System Tray

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