Unity 设置窗体透明

设置窗口透明、窗口置顶、鼠标穿透

   

方法一、

缺点：边缘不平滑，有毛边

参考博客：

1、https://alastaira.wordpress.com/2015/06/15/creating-windowless-unity-applications/

2、http://www.manew.com/thread-43230-1-1.html

3、https://blog.youkuaiyun.com/dark00800/article/details/70314432

关键代码

Shader "Custom/ChromakeyTransparent" {
    Properties {
        _MainTex ("Base (RGB)", 2D) = "white" {}
        _TransparentColourKey ("Transparent Colour Key", Color) = (0,0,0,1)
        _TransparencyTolerance ("Transparency Tolerance", Float) = 0.01 
    }
    SubShader {
        Pass {
            Tags { "RenderType" = "Opaque" }
            LOD 200
         
            CGPROGRAM
 
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"
 
            struct a2v
            {
                float4 pos : POSITION;
                float2 uv : TEXCOORD0;
            };
 
            struct v2f
            {
                float4 pos : SV_POSITION;
                float2 uv : TEXCOORD0;
            };
 
            v2f vert(a2v input)
            {
                v2f output;
                output.pos = mul (UNITY_MATRIX_MVP, input.pos);
                output.uv = input.uv;
                return output;
            }
         
            sampler2D _MainTex;
            float3 _TransparentColourKey;
            float _TransparencyTolerance;
 
            float4 frag(v2f input) : SV_Target
            {
                // What is the colour that *would* be rendered here?
                float4 colour = tex2D(_MainTex, input.uv);
             
                // Calculate the different in each component from the chosen transparency colour
                float deltaR = abs(colour.r - _TransparentColourKey.r);
                float deltaG = abs(colour.g - _TransparentColourKey.g);
                float deltaB = abs(colour.b - _TransparentColourKey.b);
 
                // If colour is within tolerance, write a transparent pixel
                if (deltaR < _TransparencyTolerance && deltaG < _TransparencyTolerance && deltaB < _TransparencyTolerance)
                {
                    return float4(0.0f, 0.0f, 0.0f, 0.0f);
                }
 
                // Otherwise, return the regular colour
                return colour;
            }
            ENDCG
        }
    }
}

using System;
using System.Runtime.InteropServices;
using UnityEngine;
 
public class TransparentWindow : MonoBehaviour
{
    [SerializeField]
    private Material m_Material;
 
    private struct MARGINS
    {
        public int cxLeftWidth;
        public int cxRightWidth;
        public int cyTopHeight;
        public int cyBottomHeight;
    }
 
    // Define function signatures to import from Windows APIs
 
    [DllImport("user32.dll")]
    private static extern IntPtr GetActiveWindow();
 
    [DllImport("user32.dll")]
    private static extern int SetWindowLong(IntPtr hWnd, int nIndex, uint dwNewLong);
     
    [DllImport("Dwmapi.dll")]
    private static extern uint DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS margins);
 
 
    // Definitions of window styles
    const int GWL_STYLE = -16;
    const uint WS_POPUP = 0x80000000;
    const uint WS_VISIBLE = 0x10000000;
 
    void Start()
    {
        #if !UNITY_EDITOR
        var margins = new MARGINS() { cxLeftWidth = -1 };
 
        // Get a handle to the window
        var hwnd = GetActiveWindow();
 
        // Set properties of the window
        // See: https://msdn.microsoft.com/en-us/library/windows/desktop/ms633591%28v=vs.85%29.aspx
        SetWindowLong(hwnd, GWL_STYLE, WS_POPUP | WS_VISIBLE);
         
        // Extend the window into the client area
        See: https://msdn.microsoft.com/en-us/library/windows/desktop/aa969512%28v=vs.85%29.aspx 
        DwmExtendFrameIntoClientArea(hwnd, ref margins);
        #endif
    }
 
    // Pass the output of the camera to the custom material
    // for chroma replacement
    void OnRenderImage(RenderTexture from, RenderTexture to)
    {
        Graphics.Blit(from, to, m_Material);
    }
}

下面是改进版，添加窗口置顶和鼠标穿透，不过依然存在毛边现象，shader还是用上面的

using System;
using System.Runtime.InteropServices;
using UnityEngine;

 
public class TransparentWindow :MonoBehaviour
{

    [SerializeField]
    public Material m_Material;

    private struct MARGINS
    {
        public int cxLeftWidth;
        public int cxRightWidth;
        public int cyTopHeight;
        public int cyBottomHeight;
    }

    // Define function signatures to import from Windows APIs

    [DllImport("user32.dll")]
    private static extern IntPtr GetActiveWindow();

    [DllImport("user32.dll")]
    private static extern uint SetWindowLong(IntPtr hWnd, int nIndex, uint dwNewLong);

    [DllImport("Dwmapi.dll")]
    private static extern uint DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS margins);

    [DllImport("user32.dll")]
    private static extern uint GetWindowLong(IntPtr hwnd,int nIndex);
    [DllImport("user32.dll")]
    private static extern int SetLayeredWindowAttributes(IntPtr hwnd,int crKey,int bAlpha,int dwFlags);

    /// <summary>   
    /// 窗口置顶
    /// </summary>   
    /// <returns></returns>
    [DllImport("user32.dll")]
    private static extern int SetWindowPos(IntPtr hWnd, int hWndInsertAfter, int x, int y, int Width, int Height, int flags);
    /// <summary>   
    /// 得到当前活动的窗口   
    /// </summary>   
    /// <returns></returns>   
    [DllImport("user32.dll")]
    private static extern IntPtr GetForegroundWindow();


   

const uint LWA_COLORKEY = 0x1;
    // Definitions of window styles
    const int GWL_STYLE = -16;
    const uint WS_POPUP = 0x80000000;
    const uint WS_VISIBLE = 0x10000000;

   

    private const uint WS_EX_LAYERED = 0x80000;
    private const int WS_EX_TRANSPARENT = 0x20;
 
    private const int GWL_EXSTYLE = (-20);
    private const int LWA_ALPHA = 0x2;
    IntPtr hwnd;
    void Start()
    {
        Application.runInBackground=true;
       var margins = new MARGINS() { cxLeftWidth = -1