Timeout MessageBox

转载

mb5fdb0f93c5ca2 2009-04-27 19:48:00

文章标签 sed ide ico 文章分类 代码人生

Here's how to call a Message Box with a timeout, the message box closes itself after the timeout period was reached.

The trick is to call an undocumented MessageBoxTimeout API located in user32.dll.

Thefunction returns an integer value of either a MB_TIMEDOUT value (indicating the timeout period was reached and the Message Box auto closed), or a value representing the button the user clicked.

Notice that the return value is always 1, when a message box with only an OK button (MB_OK Flag) is used.

//interface declaration
const
  MB_TIMEDOUT = 32000;
function MessageBoxTimeOut(hWnd: HWND; lpText: PChar; lpCaption: PChar; uType: UINT; wLanguageId: WORD; dwMilliseconds: DWORD): Integer; stdcall; external user32 name 'MessageBoxTimeoutA';
function MessageBoxTimeOutA(hWnd: HWND; lpText: PChar; lpCaption: PChar; uType: UINT; wLanguageId: WORD; dwMilliseconds: DWORD): Integer; stdcall; external user32 name 'MessageBoxTimeoutA';
function MessageBoxTimeOutW(hWnd: HWND; lpText: PWideChar; lpCaption: PWideChar; uType: UINT; wLanguageId: WORD; dwMilliseconds: DWORD): Integer; stdcall; external user32 name 'MessageBoxTimeoutW';

//implementation (Button1's OnClick event handler on Form1)
procedure TForm1.Button1Click(Sender: TObject);
var
  iRet: Integer;
  iFlags: Integer;
begin
  iFlags := MB_OK or MB_SETFOREGROUND or MB_SYSTEMMODAL or MB_ICONINFORMATION;
  MessageBoxTimeout(Application.Handle, ''Test a timeout of 2 seconds. ', 'MessageBoxTimeout Test', iFlags, 0, 2000) ;
  iFlags := MB_YESNO or MB_SETFOREGROUND or MB_SYSTEMMODAL or MB_ICONINFORMATION;
  iRet := MessageBoxTimeout(Application.Handle, 'Test a timeout of 5 seconds.', 'MessageBoxTimeout Test', iFlags, 0, 5000) ;
  case iRet of
    IDYES:
      ShowMessage('Yes');
    IDNO:
      ShowMessage('No');
    MB_TIMEDOUT:
      ShowMessage('TimedOut');
  end;
end;