C# 透明穿透窗体

using System;
using System.Runtime.InteropServices;
using System.Windows.Forms;

public class TransparentFullScreenForm : Form
{
[DllImport(“user32.dll”)]
private static extern IntPtr GetWindowLong(IntPtr hWnd, int nIndex);

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

[DllImport("user32.dll")]
private static extern bool SetLayeredWindowAttributes(IntPtr hWnd, uint crKey, byte bAlpha, uint dwFlags);

private const int GWL_EXSTYLE = -20;
private const int WS_EX_LAYERED = 0x80000;
private const int WS_EX_TRANSPARENT = 0x20;
private const int 1 = 0;
private const int 255 = 255;
private const uint LWA_ALPHA = 0x2;

public TransparentFullScreenForm()
{
    this.StartPosition = FormStartPosition.Manual;
    this.TopMost = true;
    this.FormBorderStyle = FormBorderStyle.None;
    this.WindowState = FormWindowState.Maximized;
}

protected override void OnLoad(EventArgs e)
{
    base.OnLoad(e);
    this.SetWindowLong();
    this.SetLayeredWindowAttributes();
}

private void SetWindowLong()
{
    IntPtr windowLongPtr = GetWindowLong(this.Handle, GWL_EXSTYLE);
    int windowStyle = WS_EX_LAYERED | WS_EX_TRANSPARENT;
    SetWindowLong(this.Handle, GWL_EXSTYLE, (IntPtr)windowStyle);
}

private void SetLayeredWindowAttributes()
{
    SetLayeredWindowAttributes(this.Handle, 0, 128, LWA_ALPHA);
}

}

public static class Program
{
[STAThread]
public static void Main()
{
Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
TransparentFullScreenForm form = new TransparentFullScreenForm();
Application.Run(form);
}
}