sendmsgtimeoutsendu.pas

DelphiWin32核心API参考光盘内容.是学习书籍中的源码,便于学习.

unit SendMsgTimeoutSendU;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  UserMessage: UINT;  // holds our user defined message identifier

implementation

{$R *.DFM}

procedure TForm1.FormCreate(Sender: TObject);
begin
  {register the user defined Windows messsage}
  UserMessage := RegisterWindowMessage('SendMessageTimout Test Message');
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  MsgResult: DWORD;
begin
  {send the message, and time out after 300 milliseconds}
  SendMessageTimeout(HWND_TOPMOST, UserMessage, 0, 0,
                     SMTO_NORMAL, 300, MsgResult);

  {indicate that the SendMessageTimeout function has returned}
  ShowMessage('Returned');
end;

end.