WINDOWHANDLE

The _WINDOWHANDLE function returns the window handle assigned to the current program by the OS. Windows-only.

Syntax

hwnd&& = _WINDOWHANDLE

Description

• The result is an _INTEGER64 number assigned by Windows to your running program.
• Use it to make API calls that require a window handle to be passed.
• Keyword not supported in Linux or macOS versions

Availability

• Build 20170924/68.

Examples

Example: Showing the system-default message box in Windows.

'Message Box Constant values as defined by Microsoft (MBType) CONST MB_OK& = 0 'OK button only CONST MB_OKCANCEL& = 1 'OK & Cancel CONST MB_ABORTRETRYIGNORE& = 2 'Abort, Retry & Ignore CONST MB_YESNOCANCEL& = 3 'Yes, No & Cancel CONST MB_YESNO& = 4 'Yes & No CONST MB_RETRYCANCEL& = 5 'Retry & Cancel CONST MB_CANCELTRYCONTINUE& = 6 'Cancel, Try Again & Continue CONST MB_ICONSTOP& = 16 'Error stop sign icon CONST MB_ICONQUESTION& = 32 'Question-mark icon CONST MB_ICONEXCLAMATION& = 48 'Exclamation-point icon CONST MB_ICONINFORMATION& = 64 'Letter i in a circle icon CONST MB_DEFBUTTON1& = 0 '1st button default(left) CONST MB_DEFBUTTON2& = 256 '2nd button default CONST MB_DEFBUTTON3& = 512 '3rd button default(right) CONST MB_APPLMODAL& = 0 'Message box applies to application only CONST MB_SYSTEMMODAL& = 4096 'Message box on top of all other windows CONST MB_SETFOCUS& = 65536 'Set message box as focus CONST IDOK& = 1 'OK button pressed CONST IDCANCEL& = 2 'Cancel button pressed CONST IDABORT& = 3 'Abort button pressed CONST IDRETRY& = 4 'Retry button pressed CONST IDIGNORE& = 5 'Ignore button pressed CONST IDYES& = 6 'Yes button pressed CONST IDNO& = 7 'No button pressed CONST IDTRYAGAIN& = 10 'Try again button pressed CONST IDCONTINUE& = 1 'Continue button pressed '---------------------------------------------------------------------------------------- DECLARE DYNAMIC LIBRARY "user32" FUNCTION MessageBoxA& (BYVAL hwnd AS LONG, Message AS STRING, Title AS STRING, BYVAL MBType AS _UNSIGNED LONG) END DECLARE DO msg& = 0: icon& = 0: DB& = 0 INPUT "Enter Message Box type(0 to 6 other Quits): ", BOX& IF BOX& < 0 OR BOX& > 6 THEN EXIT DO INPUT "Enter Icon&(0=none, 1=stop, 2=?, 3=!, 4=info): ", Icon& IF BOX& THEN INPUT "Enter Default Button(1st, 2nd or 3rd): ", DB& IF DB& THEN DB& = DB& - 1 'adjust value to 0, 1, or 2 msg& = MsgBox&("Box Title", "Box text message", BOX&, Icon&, DB&, 4096) 'on top of all windows PRINT "Button ="; msg& LOOP END FUNCTION MsgBox& (Title$, Message$, BoxType&, Icon&, DBtn&, Mode&) SELECT CASE Icon& CASE 1: Icon& = MB_ICONSTOP& 'warning X-sign icon CASE 2: Icon& = MB_ICONQUESTION& 'question-mark icon CASE 3: Icon& = MB_ICONEXCLAMATION& 'exclamation-point icon CASE 4: Icon& = MB_ICONINFORMATION& 'lowercase letter i in circle CASE ELSE: Icon& = 0 'no icon END SELECT IF BoxType& > 0 AND DBtn& > 0 THEN 'set default button as 2nd(256) or 3rd(512) SELECT CASE BoxType& CASE 2, 3, 6 IF DBtn& = 2 THEN Icon& = Icon& + MB_DEFBUTTON3& ELSE Icon& = Icon& + MB_DEFBUTTON2& '3 button CASE ELSE: Icon& = Icon& + MB_DEFBUTTON2& '2nd button default END SELECT END IF Focus& = MB_SetFocus& MsgBox& = MessageBoxA&(_WINDOWHANDLE, Message$, Title$, BoxType& + Icon& + Mode& + Focus&) 'focus on button END FUNCTION

Explanation: Notice how the call to the external dynamic library function MessageBoxA& passes _WINDOWHANDLE to the API and how the message box shown is created as a child of your program's window, not allowing the main window to be manipulated while the message box is open.

See also

• _WINDOWHASFOCUS
• Windows Libraries

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