WinForm实现鼠标拖动控件跟随效果

public partial class Form1 : Form{  /*   * 理解了下面的几个概念,就能完全明白相对坐标的变化.   * MouseEventArgs e 为事件鼠标参数,因此,e.Location 指示了位于事件源上的光标坐标   * Cursor.Position 获取的是相对于用户屏幕的光标坐标   * PointToClient() 方法可将屏幕坐标 Cursor.Position 换算成工作区的坐标   * 因此,换算后的 Cursor.Position 减去 e.Location 得到的始终是事件源的 Location  */  /// <summary>  /// 鼠标按下为true  /// </summary>  private bool Mousedown;  /// <summary>  /// 鼠标在事件源的位置  /// </summary>  private int CurX = 0;  private int CurY = 0;  public Form1()  {    InitializeComponent();  }  private void Controls_MouseDown(object sender, MouseEventArgs e)  {    CurX = e.X;    CurY = e.Y;    Mousedown = true;    if (sender is TextBox)    {      ((TextBox)sender).Cursor = Cursors.Arrow;    }  }  private void Controls_MouseMove(object sender, MouseEventArgs e)  {    if (Mousedown)    {      // 获取当前屏幕的光标坐标       Point pTemp = new Point(Cursor.Position.X, Cursor.Position.Y);      // 转换成工作区坐标       pTemp = this.PointToClient(pTemp);      // 定位事件源的 Location      Control control = sender as Control;      control.Location = new Point(pTemp.X - CurX, pTemp.Y - CurY);            }  }  private void Controls_MouseUp(object sender, MouseEventArgs e)  {    Mousedown = false;    if (sender is TextBox)    {      ((TextBox)sender).Cursor = Cursors.IBeam;    }  }}