WPF自定义窗体改变大小

前台代码：

后台代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Shapes;
using System.Runtime.InteropServices;
using System.Windows.Interop;

namespace SimpleZigBee
{
    /// <summary>
    /// 鼠标方向
    /// </summary>
    public enum ResizeDirection
    {
        /// <summary>
        /// 左
        /// </summary>
        Left = 1,
        /// <summary>
        /// 右
        /// </summary>
        Right = 2,
        /// <summary>
        /// 上
        /// </summary>
        Top = 3,
        /// <summary>
        /// 左上
        /// </summary>
        TopLeft = 4,
        /// <summary>
        /// 右上
        /// </summary>
        TopRight = 5,
        /// <summary>
        /// 下
        /// </summary>
        Bottom = 6,
        /// <summary>
        /// 左下
        /// </summary>
        BottomLeft = 7,
        /// <summary>
        /// 右下
        /// </summary>
        BottomRight = 8,
    }
    /// <summary>
    /// Window1.xaml 的交互逻辑
    /// </summary>
    public partial class Window1 : Window
    {
        private HwndSource _HwndSource;
        private const int WM_SYSCOMMAND = 0x112;
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);

        private Dictionary<ResizeDirection, Cursor> cursors = new Dictionary<ResizeDirection, Cursor>
        {
            {ResizeDirection.Top, Cursors.SizeNS},
            {ResizeDirection.Bottom, Cursors.SizeNS},
            {ResizeDirection.Left, Cursors.SizeWE},
            {ResizeDirection.Right, Cursors.SizeWE},
            {ResizeDirection.TopLeft, Cursors.SizeNWSE},
            {ResizeDirection.BottomRight, Cursors.SizeNWSE},
            {ResizeDirection.TopRight, Cursors.SizeNESW},
            {ResizeDirection.BottomLeft, Cursors.SizeNESW}
        };

        public Window1()
        {
            InitializeComponent();

            this.SourceInitialized += delegate(object sender, EventArgs e)
            {
                this._HwndSource = PresentationSource.FromVisual((Visual)sender) as HwndSource;
            };

            this.MouseMove += new MouseEventHandler(Window_MouseMove);
        }

        void Window_MouseMove(object sender, MouseEventArgs e)
        {
            if (Mouse.LeftButton != MouseButtonState.Pressed)
            {
                FrameworkElement element = e.OriginalSource as FrameworkElement;
                if (element != null && !element.Name.Contains("Resize")) this.Cursor = Cursors.Arrow;
            }
        }

        private void ResizePressed(object sender, MouseEventArgs e)
        {
            FrameworkElement element = sender as FrameworkElement;
            ResizeDirection direction = (ResizeDirection)Enum.Parse(typeof(ResizeDirection), element.Name.Replace("Resize", ""));

            this.Cursor = cursors[direction];
            if (e.LeftButton == MouseButtonState.Pressed) ResizeWindow(direction);
        }

        private void ResizeWindow(ResizeDirection direction)
        {
            SendMessage(_HwndSource.Handle, WM_SYSCOMMAND, (IntPtr)(61440 + direction), IntPtr.Zero);
        }
    }
}

另CodeProject中有已经封装好的类库（有相应源码下载）：http://www.codeproject.com/Articles/23138/WPF-Window-Resizing