（一）C# Windows Mobile 半透明窗体

Windows Mobile，个人心中臻至完美的系统。

不忍自己对WM的钻研成果消逝，故留作纪念。

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系列开篇，便是一个曾令自己困扰很久的问题：如何实现半透明窗体。

如果了解Win32编程，其实很简单。

主要用到了三个方法：

SetLayeredWindowAttributes

GetWindowLong

SetWindowLong

核心代码：

 private void SetWindowTransparent(byte bAlpha)
 {
     SetWindowLong(this.Handle, (int)WindowStyle.GWL_EXSTYLE,
         GetWindowLong(this.Handle, (int)WindowStyle.GWL_EXSTYLE) | (uint)ExWindowStyle.WS_EX_LAYERED);

     SetLayeredWindowAttributes(this.Handle, , bAlpha, LWA_ALPHA);
 }

效果：

完整代码：

 using System;

 using System.Collections.Generic;
 using System.ComponentModel;
 using System.Data;
 using System.Drawing;
 using System.Text;
 using System.Windows.Forms;
 using System.Runtime.InteropServices;

 namespace Demo01
 {
     public partial class Form1 : Form
     {
         public Form1()
         {
             InitializeComponent();
         }

         [DllImport("coredll.dll")]
         public extern static IntPtr GetDesktopWindow();

         [DllImport("coredll.dll")]
         public extern static bool SetLayeredWindowAttributes(IntPtr hwnd, uint crKey, byte bAlpha, uint dwFlags);
         public static uint LWA_COLORKEY = 0x00000001;
         public static uint LWA_ALPHA = 0x00000002;

         [DllImport("coredll.dll")]
         public extern static uint SetWindowLong(IntPtr hwnd, int nIndex, uint dwNewLong);
         [DllImport("coredll.dll")]
         public extern static uint GetWindowLong(IntPtr hwnd, int nIndex);

         public enum WindowStyle : int
         {
             GWL_EXSTYLE = -
         }

         public enum ExWindowStyle : uint
         {
             WS_EX_LAYERED = 0x00080000
         }

         private void SetWindowTransparent(byte bAlpha)
         {
             try
             {
                 SetWindowLong(this.Handle, (int)WindowStyle.GWL_EXSTYLE,
                     GetWindowLong(this.Handle, (int)WindowStyle.GWL_EXSTYLE) | (uint)ExWindowStyle.WS_EX_LAYERED);

                 SetLayeredWindowAttributes(this.Handle, , bAlpha, LWA_ALPHA);

             }
             catch
             {
             }
         }

         private void button1_Click(object sender, EventArgs e)
         {
             this.Close();
         }

         private void trackBar1_ValueChanged(object sender, EventArgs e)
         {
             label1.Text = "透明度(0~255): " + trackBar1.Value.ToString();
             SetWindowTransparent(Convert.ToByte(trackBar1.Value));
         }

         private void Form1_Load(object sender, EventArgs e)
         {
             Rectangle rf = Screen.PrimaryScreen.WorkingArea;

             this.Location = new Point((rf.Width - this.Width) / , (rf.Height - this.Height) / );

             //SetWindowTransparent(136);
         }
     }
 }

全部代码

工程文件：

https://files.cnblogs.com/files/lesliexin/01.%E5%8D%8A%E9%80%8F%E6%98%8E%E7%AA%97%E4%BD%93.7z

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