test.dpr

当调用另一个程序并传递参数的时候

program Test;

uses
  Forms,
  Windows,
  Messages,
  Unit1 in 'Unit1.pas' {Form1};

{$R *.res}
var
  wHandle: THandle;

  paraData: COPYDATASTRUCT;
  sMsg: string;
  I: Word;
begin
  Application.Initialize;

  CreateMutex(nil, true, 'PowerCTI');
  if GetLastError = ERROR_ALREADY_EXISTS then
  begin
    //激活已经存在的程序窗口
    wHandle := FindWindow(nil, 'Form1');
    if wHandle <> 0 then
    begin

      ShowWindow(wHandle, SW_RESTORE);//恢复已执行程序窗口
      SetForegroundWindow(wHandle); //提到最前面

      sMsg:='';
      if ParamCount > 0 then //如果参数大于0
      begin
        for I := 1 to ParamCount do
          sMsg :=sMsg+paramstr(I)+';'; //可以任意制定格式,便于解析
        paraData.dwData := 0;  //这个不用改动,可作为格式参数使用
        paraData.cbData := length(sMsg) + 1; //数据长度
        paraData.lpData := Pchar(sMsg); //数据地址
        SendMessage(wHandle, WM_COPYDATA, wHandle, integer(@paraData));
      end;
    end;
  end
  else
  begin
    Application.CreateForm(TForm1, Form1);
    Application.Run;
  end;
end.