Removing NotifyIcon from the notification area - windows

Question

Is it possible to remove NotifyIcon from the notification area (system tray) when an app terminates abruptly?
if no, how can I remove it when the app runs for the next time?

Answer 1

Abruptly? No. Your program has ceased to exist, so there's no opportunity to run any code to tell the shell that it should remove the icon.
To remove the icon, move your mouse over it. The shell will try to notify your program, realize there's nothing there anymore, and remove the icon by itself.

Answer 2

On Windows 7 and later, notify icons can be identified by a user-defined GUID. On earlier versions, they are identified by a combination of HWND and ID number instead. Since your app is not guaranteed to get the same HWND value the next time it runs, the only way you can do anything to an old icon that is identified by HWND is if you remembered the previous HWND value so you can use it to remove the old icon, before then using a new HWND to add a new icon. But with a GUID-identified icon, the GUID needs to be persistent (as it is stored in the Registry to store app settings associated with the icon), so you should be able to simply keep updating the existing icon as needed, or remove it if desired.

Answer 3

FWIW, since code doesn't exist so far, I thought I'd throw this in. I don't know if it will help or not for the OP, but it should be good guidance in the right direction.
unit csystray;
{ removes dead system tray icons, by Glenn1234 # stackoverflow.com
since this uses "less than supported by Microsoft" means, it may
not work on all operating system. It was tested on Windows XP }
interface
uses commCtrl, shellapi, windows;
type
TTrayInfo = packed record
hWnd: HWnd;
uID: UINT;
uCallBackMessage: UINT;
Reserved1: array[0..1] of longint;
Reserved2: array[0..2] of longint;
hIcon: HICON;
end;
PTBButton = ^TTBButton;
_TBBUTTON = packed record
iBitmap: Integer;
idCommand: Integer;
fsState: Byte;
fsStyle: Byte;
bReserved: array[1..2] of Byte;
dwData: Longint;
iString: Integer;
end;
TTBButton = _TBBUTTON;
procedure RemoveStaleTrayIcons;
implementation
procedure RemoveStaleTrayIcons;
const
VMFLAGS = PROCESS_VM_OPERATION or PROCESS_VM_READ OR PROCESS_VM_WRITE;
var
ProcessID: THandle;
ProcessHandle: THandle;
trayhandle: HWnd;
ExplorerButtonInfo: Pointer;
i: integer;
ButtonCount: Longint;
BytesRead: Longint;
ButtonInfo: TTBButton;
TrayInfo: TTrayInfo;
ClassNameA: Array[0..255] of char;
outlen: integer;
TrayIconData: TNotifyIconData;
begin
// walk down the window hierarchy to find the notification area window
trayhandle := FindWindow('Shell_TrayWnd', '');
trayhandle := FindWindowEx(trayhandle, 0, 'TrayNotifyWnd', nil);
trayhandle := FindWindowEx(trayhandle, 0, 'SysPager', nil);
trayhandle := FindWindowEx(trayhandle, 0, 'ToolbarWindow32', nil);
if trayhandle = 0 then exit;
// find the notification area process and open it up for reading.
GetWindowThreadProcessId(trayhandle, #ProcessID);
ProcessHandle := OpenProcess(VMFLAGS, false, ProcessID);
ExplorerButtonInfo := VirtualAllocEx(ProcessHandle, nil, Sizeof(TTBButton),
MEM_RESERVE or MEM_COMMIT, PAGE_READWRITE);
// the notification area is a tool bar. Get the number of buttons.
ButtonCount := SendMessage(trayhandle, TB_BUTTONCOUNT, 0, 0);
if ExplorerButtonInfo <> nil then
try
// iterate the buttons & check.
for i := (ButtonCount - 1) downto 0 do
begin
// get button information.
SendMessage(trayhandle, TB_GETBUTTON, i, LParam(ExplorerButtonInfo));
ReadProcessMemory(ProcessHandle, ExplorerButtonInfo, #ButtonInfo,
Sizeof(TTBButton), BytesRead);
// if there's tray data, read and process
if Buttoninfo.dwData <> 0 then
begin
ReadProcessMemory(ProcessHandle, PChar(ButtonInfo.dwData),
#TrayInfo, Sizeof(TTrayInfo), BytesRead);
// here's the validation test, this fails if the master window is invalid
outlen := GetClassName(TrayInfo.hWnd, ClassNameA, 256);
if outlen < 1 then
begin
// duplicate the shell icon removal, i.e. my component's DeleteTray
TrayIconData.cbSize := sizeof(TrayIconData);
TrayIconData.Wnd := TrayInfo.hWnd;
TrayiconData.uID := TrayInfo.uID;
TrayIconData.uCallbackMessage := TrayInfo.uCallBackMessage;
Shell_NotifyIcon(NIM_DELETE, #TrayIconData);
end;
end;
end;
finally
VirtualFreeEx(ProcessID, ExplorerButtonInfo, Sizeof(TTBButton), MEM_RELEASE);
end;
end;
end.