设置窗体可以使用鼠标拖动大小 通过

private void Window_Loaded(object sender, RoutedEventArgs e)

        {

            // 获取窗体句柄 

            IntPtr hwnd = new System.Windows.Interop.WindowInteropHelper(this).Handle;



            // 获得窗体的 样式 

            int oldstyle = NativeMethods.GetWindowLong(hwnd, NativeMethods.GWL_STYLE);



            // 更改窗体的样式为无边框窗体 

            NativeMethods.SetWindowLong(hwnd, NativeMethods.GWL_STYLE, oldstyle & ~NativeMethods.WS_CAPTION);



            // SetWindowLong(hwnd, GWL_EXSTYLE, oldstyle & ~WS_EX_LAYERED); 

            // 1 | 2 << 8 | 3 << 16  r=1,g=2,b=3 详见winuse.h文件 

            // 设置窗体为透明窗体 

            NativeMethods.SetLayeredWindowAttributes(hwnd, 1 | 2 << 8 | 3 << 16, 0, NativeMethods.LWA_ALPHA);



            // 创建圆角窗体  12 这个值可以根据自身项目进行设置 

            NativeMethods.SetWindowRgn(hwnd, NativeMethods.CreateRoundRectRgn(0, 0, Convert.ToInt32(this.ActualWidth), Convert.ToInt32(this.ActualHeight), 12, 12), true); 

        }

　　

NativeMethods.cs的代码：

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;



namespace SEsoft

{

    public class NativeMethods

    {

        /// <summary> 

        /// 带有外边框和标题的windows的样式 

        /// </summary> 

        public const int WS_CAPTION = 0X00C0000;



        /// <summary> 

        /// window 扩展样式 分层显示 

        /// </summary> 

        public const int WS_EX_LAYERED = 0x00080000;



        /// <summary> 

        /// 带有alpha的样式 

        /// </summary> 

        public const int LWA_ALPHA = 0x00000002;



        /// <summary> 

        /// 颜色设置 

        /// </summary> 

        public const int LWA_COLORKEY = 0x00000001;



        /// <summary> 

        /// window的基本样式 

        /// </summary> 

        public const int GWL_STYLE = -16;



        /// <summary> 

        /// window的扩展样式 

        /// </summary> 

        public const int GWL_EXSTYLE = -20;



        /// <summary> 

        /// 设置窗体的样式 

        /// </summary> 

        /// <param name="handle">操作窗体的句柄</param> 

        /// <param name="oldStyle">进行设置窗体的样式类型.</param> 

        /// <param name="newStyle">新样式</param> 

        [System.Runtime.InteropServices.DllImport("User32.dll")]

        public static extern void SetWindowLong(IntPtr handle, int oldStyle, int newStyle);



        /// <summary> 

        /// 获取窗体指定的样式. 

        /// </summary> 

        /// <param name="handle">操作窗体的句柄</param> 

        /// <param name="style">要进行返回的样式</param> 

        /// <returns>当前window的样式</returns> 

        [System.Runtime.InteropServices.DllImport("User32.dll")]

        public static extern int GetWindowLong(IntPtr handle, int style);



        /// <summary> 

        /// 设置窗体的工作区域. 

        /// </summary> 

        /// <param name="handle">操作窗体的句柄.</param> 

        /// <param name="handleRegion">操作窗体区域的句柄.</param> 

        /// <param name="regraw">if set to <c>true</c> [regraw].</param> 

        /// <returns>返回值</returns> 

        [System.Runtime.InteropServices.DllImport("User32.dll")]

        public static extern int SetWindowRgn(IntPtr handle, IntPtr handleRegion, bool regraw);



        /// <summary> 

        /// 创建带有圆角的区域. 

        /// </summary> 

        /// <param name="x1">左上角坐标的X值.</param> 

        /// <param name="y1">左上角坐标的Y值.</param> 

        /// <param name="x2">右下角坐标的X值.</param> 

        /// <param name="y2">右下角坐标的Y值.</param> 

        /// <param name="width">圆角椭圆的width.</param> 

        /// <param name="height">圆角椭圆的height.</param> 

        /// <returns>hRgn的句柄</returns> 

        [System.Runtime.InteropServices.DllImport("gdi32.dll")]

        public static extern IntPtr CreateRoundRectRgn(int x1, int y1, int x2, int y2, int width, int height);



        /// <summary> 

        /// Sets the layered window attributes. 

        /// </summary> 

        /// <param name="handle">要进行操作的窗口句柄</param> 

        /// <param name="colorKey">RGB的值</param> 

        /// <param name="alpha">Alpha的值，透明度</param> 

        /// <param name="flags">附带参数</param> 

        /// <returns>true or false</returns> 

        [System.Runtime.InteropServices.DllImport("User32.dll")]

        public static extern bool SetLayeredWindowAttributes(IntPtr handle, uint colorKey, byte alpha, int flags);

    }

}