Here I am again with a new eVB example project.
This module is similar in purpose to the
Taskbar Icon example, but it adds an icon to the taskbar status area
(or systray
). You can respond to taps and double-taps, currently right 'click' doesn't seem to work.
While eVB does not have the ability to subclass forms and inspect or modify window messages, the way this works is by
(ab
)using the
MouseDown event of the form. The
Shell_NotifyIcon API function lets you specify which window message to send when the user interacts with your icon. eVB is already handling the mouse related event messages so this message will appear as a regular
MouseDown message to your form. The example project includes code to differentiate between regular
MouseDown messages and ones triggered from the notify icon, so you'll be able to handle both appropriately.
This method is similar to the approach Microsoft used in
Q176085, which I used as a reference for this module. However, unlike the article, I had to use the
MouseDown event instead of
MouseMove, because Windows CE seems to handle these messages differently and sending
WM_MOUSEMOVE does not trigger the corresponding event in eVB.
An interesting side note is that the Microsoft article claims that this functionality is possible due to the new abilities of VB5/VB6 (most notably the AddressOf operator). However, the given example does not make use of these functionalities at all, and in theory would work just as well in VB4 (or indeed, eVB).
To use this module, add an ImageList to your form, add the image
(s
) as per normal, then call the
NotifyIcon_Add function whenever you want to show the icon. You can use
NotifyIcon_Modify to change the currently displayed icon, and
NotifyIcon_Remove to remove it from the tray. The example project demonstrates all of these functions.
Make sure to always call
NotifyIcon_Remove when your application ends, or the icon will remain until the user taps on it to make it go away, in addition, memory may be leaked because icon handles will not be properly cleaned up.
Currently, only one icon is supported per application.
A complete application could look like this:
Option Explicit
Private Sub Form_Load()
ImageList.Add "icon_small.bmp"
End Sub
Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
'This procedure receives the callbacks from the System Tray icon.
Dim lngResult As Long
Dim lngMessage As Long
'The value of X will vary depending upon the scalemode setting.
If ScaleMode = vbPixels Then
lngMessage = X
Else
lngMessage = X / Screen.TwipsPerPixelX
End If
Select Case lngMessage
Case WM_LBUTTONUP 'The user has tapped on the icon once.
Show
NotifyIcon_Remove
Case WM_LBUTTONDBLCLK 'The user has double-tapped on the icon.
Show
NotifyIcon_Remove
Case WM_RBUTTONUP 'The user has tapped on the icon while holding Ctrl, does not seem to work for now.
Show
NotifyIcon_Remove
End Select
End Sub
Private Sub Form_Unload(Cancel As Integer)
Hide
NotifyIcon_Add hWnd, ImageList.hImageList, 0
Cancel = 1
End Sub
I am still looking into the ability of displaying popup menus.
I have attached a screenshot of the example application when visible
(no tray icon
) and minimized to the tray.
Just like the taskbar icon example, this is bound to the same limitations as other icons represented by the eVB ImageList. Most notably, transparency is not allowed.
Links:
GitHub RepoEdited by WinCEDev 2023-02-12 2:20 AM
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