利用SendMessage模拟鼠标左键双击打开文件，但是文件没打开，请熟悉Windows编程的大神指点

Question

利用SendMessage模拟鼠标左键双击打开文件，但是文件没打开。打印4次结果0。请熟悉Windows编程的大神指点

// SendMessage.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include "windows.h"
#include "stdlib.h"
#include "Winuser.h"

int main(int argc, char* argv[])
{
    HWND desktop = GetDesktopWindow();//屏幕窗口句柄
    desktop=GetWindow(desktop,GW_CHILD);
    /*8DWORD ProcessId;//要打开窗口的进程标识符
    ::GetWindowThreadProcessId(desktop, &ProcessId);
    HANDLE processH = ::OpenProcess(PROCESS_ALL_ACCESS, FALSE, ProcessId);*/
    int x = 30;
    int y = 24;
    ::SetCursorPos(x,y);
    //Sleep(1000);
    LRESULT result1 = ::SendMessage(desktop, WM_LBUTTONDOWN,VK_LBUTTON,MAKELPARAM(x,y));
    LRESULT result2 = ::SendMessage(desktop, WM_LBUTTONUP,0,MAKELPARAM(x,y));
    LRESULT result3 = ::SendMessage(desktop, WM_LBUTTONDOWN,VK_LBUTTON,MAKELPARAM(x,y));
    LRESULT result4 = ::SendMessage(desktop, WM_LBUTTONUP,0,MAKELPARAM(x,y));
    printf("%d %d %d %d\n",result1,result2,result3,result4);
    //::SendMessage(NULL, WM_LBUTTONDOWN, 0,(y<<16)|x);
    //::SendMessage(NULL, WM_LBUTTONUP, 0,(y<<16)|x);

    return 0;
}

Answer 1

1.把SendMessage 改成PostMessage
2.在两次点击中间插入sleep
3.以上两个方法不行，就用单击然后发送回车按键