Unity设置窗口置顶以及无边框窗口

using System;
using System.Collections;
using System.Runtime.InteropServices;
using System.Diagnostics;
using UnityEngine;
public class WindowMod: MonoBehaviour
{
public Rect screenPosition;
[DllImport("user32.dll")]
static extern IntPtr SetWindowLong (IntPtr hwnd,int _nIndex ,int dwNewLong);
[DllImport("user32.dll")]
static extern bool SetWindowPos (IntPtr hWnd, int hWndInsertAfter, int X, int Y, int cx, int cy, uint uFlags);
[DllImport("user32.dll")]
static extern IntPtr GetForegroundWindow ();
// not used rigth now
//const uint SWP_NOMOVE = 0x2;
//const uint SWP_NOSIZE = 1;
//const uint SWP_NOZORDER = 0x4;
//const uint SWP_HIDEWINDOW = 0x0080;
const uint SWP_SHOWWINDOW = 0x0040;
const int GWL_STYLE = -16;
const int WS_BORDER = 1;
void Start ()
{

     /*  screenPosition.x = (int)((Screen.currentResolution.width - screenPosition.width) / 2);
        screenPosition.y = (int)((Screen.currentResolution.height - screenPosition.height) / 2);
        if(Screen.currentResolution.height<=768){
            screenPosition.y = 0;
        }*/
SetWindowLong(GetForegroundWindow (), GWL_STYLE, WS_BORDER);
bool result = SetWindowPos (GetForegroundWindow (), 0,(int)screenPosition.x,(int)screenPosition.y, (int)screenPosition.width,(int) screenPosition.height, SWP_SHOWWINDOW);
}
}