Unity打包PC端各种屏幕适配，无边框，最小化，显示可拖拽部分

using UnityEngine;
using System.Collections;
using UnityEngine.EventSystems;
//using UnityEngine.SceneManagement;
using System;
using UnityEngine.UI;
using System.Runtime.InteropServices;

public class DrawWindow : MonoBehaviour
{

    //private GameObject go;
    private 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();

    [DllImport("user32.dll")]
    public static extern bool ReleaseCapture();
    [DllImport("user32.dll")]
    public static extern bool SendMessage(IntPtr hwnd, int wMsg, int wParam, int lParam);

    [DllImport("user32.dll")]
    public static extern bool ShowWindow(IntPtr hwnd, int nCmdShow);

    /// <summary>  
    /// 窗口宽度  
    /// </summary>  
    public int winWidth;
    /// <summary>  
    /// 窗口高度  
    /// </summary>  
    public int winHeight;
    /// <summary>  
    /// 窗口左上角x  
    /// </summary>  
    public int winPosX;
    /// <summary>  
    /// 窗口左上角y  
    /// </summary>  
    public int winPosY;

    const uint SWP_SHOWWINDOW = 0x0040;
    const int GWL_STYLE = -16;
    const int WS_BORDER = 1;
    const int WS_POPUP = 0x800000;
    const int SW_SHOWMINIMIZED = 2; //{最小化, 激活}
    const int SW_SHOWMAXIMIZED = 3; //{最大化, 激活} 

    public void btn_onclick()
    { //最小化 
        ShowWindow(GetForegroundWindow(), SW_SHOWMINIMIZED);
    }
    public void btn_onclickxx()
    { //最大化
        ShowWindow(GetForegroundWindow(), SW_SHOWMAXIMIZED);

    }
    public void btn_onclickxxx()
    {//窗口化
        Screen.fullScreen = false;
        Screen.SetResolution(900, 540, false);
    }

    public void btn_onclickxxxx()
    {//默认分辨率无边框显示(可以自由根据winWidth和winHeight的值调整无边框的分辨率)
        
        winWidth = 900;
        winHeight = 540;
        //显示器支持的所有分辨率  
        int i = Screen.resolutions.Length;

        int resWidth = Screen.resolutions[i - 1].width;
        int resHeight = Screen.resolutions[i - 1].height;

        winPosX = resWidth / 2 - winWidth / 2;
        winPosY = resHeight / 2 - winHeight / 2;

        SetWindowLong(GetForegroundWindow(), GWL_STYLE, WS_POPUP);
        bool result = SetWindowPos(GetForegroundWindow(), 0, winPosX, winPosY, winWidth, winHeight, SWP_SHOWWINDOW);
    }

    public void btn_onclickxxxxx()
    {//第二分辨率显示
        Resolution[] resolutions = Screen.resolutions;
        int i = resolutions.Length;
        winWidth = resolutions[i - 2].width;
        winHeight = resolutions[i-2].height;

        //
        

        int resWidth = Screen.resolutions[i - 1].width;
        int resHeight = Screen.resolutions[i - 1].height;

        winPosX = resWidth / 2 - winWidth / 2;
        winPosY = resHeight / 2 - winHeight / 2;

        SetWindowLong(GetForegroundWindow(), GWL_STYLE, WS_POPUP);
        bool result = SetWindowPos(GetForegroundWindow(), 0, winPosX, winPosY, winWidth, winHeight, SWP_SHOWWINDOW);
    }

    IntPtr Handle;
    bool bx;

    bool isMainScene = false;

    void Awake()
    {
        bx = false;
#if UNITY_STANDALONE_WIN
        Resolution[] r = Screen.resolutions;
        screenPosition = new Rect((r[r.Length - 1].width - Screen.width) / 2, (r[r.Length - 1].height - Screen.height) / 2, Screen.width, Screen.height);

        SetWindowLong(GetForegroundWindow(), GWL_STYLE, WS_POPUP);//将网上的WS_BORDER替换成WS_POPUP  
        Handle = GetForegroundWindow();   //FindWindow ((string)null, "popu_windows");
        SetWindowPos(GetForegroundWindow(), 0, (int)screenPosition.x, (int)screenPosition.y, (int)screenPosition.width, (int)screenPosition.height, SWP_SHOWWINDOW);
#endif
        btn_onclickxxxxx();

        //go = transform.Find("go").gameObject;
        //DontDestroyOnLoad(go);
    }

    void Update()
    {

        MyDrag();
//测试各个分辨率的按键。
        if (Input.GetKey(KeyCode.A))
        {
            btn_onclickxxxxx();
        }
        if (Input.GetKey(KeyCode.Escape))
        {
            btn_onclick();
        }
        if (Input.GetKey(KeyCode.W))
        {
            btn_onclickxx();
        }
        if (Input.GetKey(KeyCode.Q))
        {
            btn_onclickxxxx();
        }
    }

    /// <summary>
    /// 自定义的只能在某些区域内点击有效的拖拽
    /// </summary>
    private void MyDrag()
    {
        if (bx)
        { //这样做为了区分界面上面其它需要滑动的操作
            ReleaseCapture();
            SendMessage(Handle, 0xA1, 0x02, 0);
            SendMessage(Handle, 0x0202, 0, 0);
        }
    }

    public void OnPointerEnter(PointerEventData eventData)
    {
        bx = true;
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        bx = false;
    }
    void Start()
    {
    }

}