c# 鼠标穿透窗体 张宇轩

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
);
private void MaskForm_Load(object sender, EventArgs e)
{

//要时窗体恢复正常，只要执行以下语句：
// this.FormBorderStyle = FormBorderStyle.None;
CanPenetrate();
}

/// <summary>
/// 使窗口有鼠标穿透功能
/// </summary>
public void CanPenetrate()
{
uint intExTemp = GetWindowLong(this.Handle, GWL_EXSTYLE);
uint oldGWLEx = SetWindowLong(this.Handle, GWL_EXSTYLE, WS_EX_TRANSPARENT | WS_EX_LAYERED);
SetLayeredWindowAttributes(this.Handle, 0, 200, LWA_ALPHA);
}