Article: Q149276
Product(s): Microsoft Visual Basic for Windows
Version(s): 4.0,5.0,6.0
Operating System(s):
Keyword(s): kbAPI kbVBp kbVBp400 kbGrpDSVB kbDSupport
Last Modified: 28-JAN-2001
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The information in this article applies to:
- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0
- Microsoft Visual Basic Learning Edition for Windows, versions 5.0, 6.0
- Microsoft Visual Basic Professional Edition for Windows, versions 5.0, 6.0
- Microsoft Visual Basic Enterprise Edition for Windows, versions 5.0, 6.0
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SUMMARY
=======
The Windows API provides the ability to add, modify, and remove icons from the
System Tray, or Taskbar Notification Area, available in the Windows 95, Windows
98, Windows Me, Windows NT 4.0, and Windows 2000 shell. This functionality can
be provided using only the Shell_NotifyIcon function that is exported by
Shell32.dll. This API function also provides the ability to specify a text
string for the ToolTip that is displayed when a user pauses with the mouse
pointer over the icon. The step-by-step example in this article creates a Visual
Basic program which demonstrates how to use this API function.
The ability to take some action if the icon in the Taskbar Notification Area is
clicked depends on a callback function. Because Visual Basic 4.0 does not
support callback functions directly, there is no way to show a form or execute
some code using solely Visual Basic 4.0. This functionality was added in Visual
Basic 5.0 (and later) with the addition of the AddressOf operator. A number of
options are available to Visual Basic 4.0 developers that can provide callback
functionality, including the Message Blaster OCX, the OCX mentioned in the
Microsoft Systems Journal article noted in the "References" section of this
article, or the Callback OLE server that is detailed in Bruce McKinney's book,
Hardcore Visual Basic. For more information on any of these options, see the
"References" section. Because these products do not include Visual Basic,
Microsoft Product Support Services does not support their use.
MORE INFORMATION
================
The following example creates a one-form Visual Basic project that shows how to
use the Shell_NotifyIcon API function.
Step-by-Step Example
--------------------
1. Start Visual Basic. Form1 is created by default.
2. Change the form's icon property to the icon that should be shown in the
Taskbar Notification Area.
3. Draw three CommandButtons onto the form.
4. Select Module from the Insert menu to add a single code module to the
project.
5. Add the following code, consisting of function, type, and constant
declarations, to Module1:
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
Global Const NIM_ADD = 0
Global Const NIM_MODIFY = 1
Global Const NIM_DELETE = 2
Global Const NIF_MESSAGE = 1
Global Const NIF_ICON = 2
Global Const NIF_TIP = 4
Declare Function Shell_NotifyIconA Lib "SHELL32" _
(ByVal dwMessage As Long, lpData As NOTIFYICONDATA) As Integer
6. The following code is a function that takes the parameters that need to be
set for the NOTIFYICONDATA type and returns a variable of this type. Add to
Form1:
Private Function setNOTIFYICONDATA(hWnd As Long, ID As Long, _
Flags As Long, CallbackMessage As Long, Icon As Long, _
Tip As String) As NOTIFYICONDATA
Dim nidTemp As NOTIFYICONDATA
nidTemp.cbSize = Len(nidTemp)
nidTemp.hWnd = hWnd
nidTemp.uID = ID
nidTemp.uFlags = Flags
nidTemp.uCallbackMessage = CallbackMessage
nidTemp.hIcon = Icon
nidTemp.szTip = Tip & Chr$(0)
setNOTIFYICONDATA = nidTemp
End Function
7. The three procedures in this block of code call the function created in step
5 to add, modify, and remove Taskbar Notification Area icons. Add this code
to Form1 also:
Private Sub Command1_Click()
'Add an icon. This procedure uses the icon specified in
'the Icon property of Form1. This can be modified as desired.
Dim i As Integer
Dim s As String
Dim nid As NOTIFYICONDATA
s = InputBox("Enter string:")
nid = setNOTIFYICONDATA(hWnd:=Form1.hWnd, _
ID:=vbNull, _
Flags:=NIF_MESSAGE Or NIF_ICON _
Or NIF_TIP, _
CallbackMessage:=vbNull, _
Icon:=Form1.Icon, _
Tip:=s)
i = Shell_NotifyIconA(NIM_ADD, nid)
End Sub
Private Sub Command2_Click()
'Modify an existing icon. This procedure uses the icon
'specified in the Icon property of Form1. This can be modified
'as desired.
Dim i As Integer
Dim s As String
Dim nid As NOTIFYICONDATA
s = InputBox("Enter string:")
nid = setNOTIFYICONDATA(hWnd:=Form1.hWnd, _
ID:=vbNull, _
Flags:=NIF_MESSAGE Or NIF_ICON _
Or NIF_TIP, _
CallbackMessage:=vbNull, _
Icon:=Form1.Icon, _
Tip:=s)
i = Shell_NotifyIconA(NIM_MODIFY, nid)
End Sub
Private Sub Command3_Click()
'Delete an existing icon.
Dim i As Integer
Dim nid As NOTIFYICONDATA
nid = setNOTIFYICONDATA(hWnd:=Form1.hWnd, _
ID:=vbNull, _
Flags:=NIF_MESSAGE Or NIF_ICON _
Or NIF_TIP, _
CallbackMessage:=vbNull, _
Icon:=Form1.Icon, _
Tip:="")
i = Shell_NotifyIconA(NIM_DELETE, nid)
End Sub
8. Press the F5 key or select Start from the Run menu to run the application.
Click the first button and enter a text string to add an icon. Click the
second button to modify an existing icon, and the third to delete the icon.
REFERENCES
==========
Hardcore Visual Basic, Bruce McKinney, Microsoft Press 1995.
Microsoft Win32 SDK, Shell_NotifyIcon and NOTIFYICONDATA.
Microsoft Systems Journal, February 1996, The Visual Programmer, page 93.
Visual Basic Programmer's Journal, March 1996, Q&A, page 136.
For additional information, click the article number below to view the article in
the Microsoft Knowledge Base:
Q162613 HOWTO: Manipulate Icons in the System Tray with Visual Basic
Additional query words: system tray
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Keywords : kbAPI kbVBp kbVBp400 kbGrpDSVB kbDSupport
Technology : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVB600Search kbVBA500 kbVBA600 kbVB500 kbVB600 kbVB400Search kbVB400
Version : :4.0,5.0,6.0
Issue type : kbhowto
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