基本思路很简单：

先得到鼠标点击的位置并记录，鼠标移动时得到移动后的位置计算出差值，然后平移。

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.Navigation;  
    using System.Windows.Shapes;  
    namespace DragWindowTest  
    {  
        /// <summary>  
        /// MainWindow.xaml 的交互逻辑  
        /// </summary>  
        public partial class MainWindow : Window  
        {  
            public MainWindow()  
            {  
                InitializeComponent();  
            }  
            private static bool IsDrag = false;  
            private double enterX;  
            private double enterY;  
            private void Window_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)  
            {  
                IsDrag = true;  
                enterX = e.GetPosition(this).X;  
                enterY = e.GetPosition(this).Y;  
            }  
      
            private void Window_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)  
            {  
                IsDrag = false;  
                enterX = 0;  
                enterY = 0;  
            }  
            private void Window_MouseMove(object sender, MouseEventArgs e)  
            {  
                if (IsDrag)  
                {  
                    this.Left += e.GetPosition(this).X - enterX;  
                    this.Top += e.GetPosition(this).Y - enterY;  
                }  
            }  
       
        }  
    }