VB6 鼠标穿透窗体

Option Explicit

Private Declare Funсtion GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long) As Long
Private Declare Funсtion SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hWnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare Funсtion SetLayeredWindowAttributes Lib "user32" (ByVal hWnd As Long, ByVal crKey As Long, ByVal bAlpha As Byte, ByVal dwFlags As Long) As Long

Const LWA_COLORKEY = &H1
Const LWA_ALPHA = &H2
Const GWL_EXSTYLE = (-20)
Const WS_EX_LAYERED = &H80000
Const WS_EX_TRANSPARENT As Long = &H20&

Private Sub Form_Load()
Dim Ret As Long

Ret = GetWindowLong(Me.hWnd, GWL_EXSTYLE) 
Ret = Ret Or WS_EX_LAYERED Or WS_EX_TRANSPARENT 
SetWindowLong Me.hWnd, GWL_EXSTYLE, Ret 
SetLayeredWindowAttributes Me.hWnd, 0, 200, LWA_ALPHA'第三个参数200是设置透明度 

End Sub

C# 版本：

同样该功能需要加载命名空间

using System.Runtime.InteropServices;

代码如下:

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> 
    public void SetPenetrate()
    {
        GetWindowLong(this.Handle, GWL_EXSTYLE);
        SetWindowLong(this.Handle, GWL_EXSTYLE, WS_EX_TRANSPARENT | WS_EX_LAYERED);
        SetLayeredWindowAttributes(this.Handle, 0, 100, LWA_ALPHA);
    }