C#创建鼠标能穿透的窗体

本功能应用广泛，出自一时的兴趣。编出如下代码进行记录，便于以后查阅。主要使用WinApi函数为：SetWindowLong，GetWindowLong，SetLayeredWindowAttributes。
[code lang=”csharp”]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 = 0x2;

[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
);

///

public void SetPenetrate()
{
this.TopMost = true;
GetWindowLong(this.Handle, GWL_EXSTYLE);
SetWindowLong(this.Handle, GWL_EXSTYLE, WS_EX_TRANSPARENT | WS_EX_LAYERED);
SetLayeredWindowAttributes(this.Handle, 0, 100, LWA_ALPHA);
}[/code]
把SetPenetrate()方法放到Load事件里面就可以把当前窗口设置成具有鼠标穿透效果的窗体。