Delphi 通得进程ID获取主窗口句柄

只知道进程ID，获取主窗口句柄的方法如下：

1. 通过EnumWindows枚举所有窗口
2. 使用GetWindowThreadProcessID，通过窗口句柄获取进程ID
3. 比便获取的进程ID与当前已知的进程ID，判断是否为需要的窗口

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 =  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 := ;

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

    Result := EI.HWND;

  end;

begin

  if hPID <>  then

    Result := FindMainWindow(hPID)

  else

    Result:=;

end;

by lin 2016-11-13