delphi 通得进程ID获取主窗口句柄

代码如下：

function GetHwndFromProcess(const hPID: THandle): THandle;

  type

    PEnumInfo = ^TEnumInfo;

    TEnumInfo = record

    ProcessID: DWORD;

    HWND: THandle;

  end;

  function EnumWindowsProc(Wnd: DWORD; var EI: TEnumInfo): Bool; stdcall;

  var

    PID: DWORD;

    h: THandle;

  begin

    Result := True;

    GetWindowThreadProcessID(Wnd, @PID);

    if PID = EI.ProcessID then

    begin

      h := GetWindowLong(Wnd, GWL_HWNDPARENT);

      if h = 0 then

      begin

        EI.HWND := Wnd;

        Result := False;

      end;

    end;

    if not Result then

      EI.HWND := WND;

  end;

  function FindMainWindow(PID: DWORD): DWORD;

  var

    EI: TEnumInfo;

  begin

    EI.ProcessID := PID;

    EI.HWND := 0;

    EnumWindows(@EnumWindowsProc, Integer(@EI));

    Result := EI.HWND;

  end;

begin

  if hPID <> 0 then

    Result := FindMainWindow(hPID)

  else

    Result:=0;

end;