C# 鼠标穿透窗体功能

通过以下代码，在窗体启动后调用方法SetPenetrate() 即可实现窗体的穿透功能。

同样该功能需要加载命名空间

using System.Runtime.InteropServices;

　　　　 private const uint WS_EX_LAYERED = 0x80000;
        private const int WS_EX_TRANSPARENT = 0x20;
        private const int GWL_STYLE = (-16);
        private const int GWL_EXSTYLE = (-20);
        private const int LWA_ALPHA = 0;
 
        [DllImport("user32", EntryPoint = "SetWindowLong")]
        private static extern uint SetWindowLong(
        IntPtr hwnd,
        int nIndex,
        uint dwNewLong
        );
 
        [DllImport("user32", EntryPoint = "GetWindowLong")]
        private static extern uint GetWindowLong(
        IntPtr hwnd,
        int nIndex
        );
 
        [DllImport("user32", EntryPoint = "SetLayeredWindowAttributes")]
        private static extern int SetLayeredWindowAttributes(
        IntPtr hwnd,
        int crKey,
        int bAlpha,
        int dwFlags
        );
　　/// <summary>
　　/// 设置窗体具有鼠标穿透效果
　　/// </summary>
　　/// <param name="flag">true穿透，false不穿透</param>
　　public void SetPenetrate(bool flag = true)
　　{
　　　　uint style = GetWindowLong(this.Handle, GWL_EXSTYLE);
　　　　if (flag)
　　　　　　SetWindowLong(this.Handle, GWL_EXSTYLE, style | WS_EX_TRANSPARENT | WS_EX_LAYERED);
　　　　else
　　　　　　SetWindowLong(this.Handle, GWL_EXSTYLE, style & ~(WS_EX_TRANSPARENT | WS_EX_LAYERED));
　　　　SetLayeredWindowAttributes(this.Handle, 0, 100, LWA_ALPHA);
　　}