C#中WinForm控件的拖动和缩放的实现代码

C# WinForm控件的拖动和缩放是个很有用的功能。实现起来其实很简单的，主要是设计控件的MouseDown、MouseLeave、MouseMove事件,下面的几个步骤将逐步实现C# WinForm控件的拖动和缩放的功能。

1、定义一个枚举类型，描述光标状态  

private enum EnumMousePointPosition  
  {  
  MouseSizeNone  = 0, //'无  
  MouseSizeRight  = 1, //'拉伸右边框  
  MouseSizeLeft  = 2, //'拉伸左边框  
  MouseSizeBottom  = 3, //'拉伸下边框  
  MouseSizeTop  = 4, //'拉伸上边框  
  MouseSizeTopLeft = 5, //'拉伸左上角  
  MouseSizeTopRight = 6, //'拉伸右上角  
  MouseSizeBottomLeft = 7, //'拉伸左下角  
  MouseSizeBottomRight= 8, //'拉伸右下角  
  MouseDrag  = 9  // '鼠标拖动  
  }  

2、定义几个变量  

 const int Band = 5;  
  const int MinWidth=10;  
  const int MinHeight=10;  
  private EnumMousePointPosition m_MousePointPosition;  
  private Point p,p1;  

3、定义自己的MyMouseDown事件   

private void MyMouseDown(object sender,System.Windows.Forms.MouseEventArgs e)  
{  
 p.X=e.X;  
 p.Y=e.Y;  
 p1.X=e.X;  
 p1.Y=e.Y;    
}  

4、定义自己的MyMouseLeave事件  

 private void MyMouseLeave(object sender, System.EventArgs e)  
{  
 m_MousePointPosition = EnumMousePointPosition.MouseSizeNone;  
 this.Cursor=Cursors.Arrow;  
}  

5、设计一个函数，确定光标在控件不同位置的样式   

private EnumMousePointPosition MousePointPosition(Size size,System.Windows.Forms.MouseEventArgs e)  
{  
  
 if ((e.X >= -1 * Band) | (e.X <= size.Width) | (e.Y >= -1 * Band) | (e.Y <= size.Height))   
 {  
 if (e.X < Band)   
 {  
  if (e.Y < Band) {return EnumMousePointPosition.MouseSizeTopLeft;}  
  else   
  {  
  if (e.Y > -1 * Band + size.Height)   
  {return EnumMousePointPosition.MouseSizeBottomLeft;}  
  else   
  {return EnumMousePointPosition.MouseSizeLeft;}  
  }  
 }  
 else  
 {  
  if (e.X > -1 * Band + size.Width)  
  {  
  if (e.Y < Band)  
  {return EnumMousePointPosition.MouseSizeTopRight;}  
  else   
  {  
   if (e.Y > -1 * Band + size.Height)  
   {return EnumMousePointPosition.MouseSizeBottomRight;}  
   else  
   {return EnumMousePointPosition.MouseSizeRight;}  
  }  
  }  
  else  
  {  
  if (e.Y < Band)   
  {return EnumMousePointPosition.MouseSizeTop;}  
  else  
  {  
   if (e.Y > -1 * Band + size.Height)   
   {return EnumMousePointPosition.MouseSizeBottom;}  
   else   
   {return EnumMousePointPosition.MouseDrag;}  
  }  
  }  
 }  
 }  
 else   
 {return EnumMousePointPosition.MouseSizeNone;}  
}  

6、定义自己的MyMouseMove事件，在这个事件里，会使用上面设计的函数    

  private void MyMouseMove(object sender,System.Windows.Forms.MouseEventArgs e)  
  {  
  Control lCtrl =(sender as Control);  
  
  if (e.Button==MouseButtons.Left)  
  {  
   switch (m_MousePointPosition)  
   {  
   case EnumMousePointPosition.MouseDrag:     
    lCtrl.Left =lCtrl.Left+ e.X - p.X;  
    lCtrl.Top =lCtrl.Top+ e.Y - p.Y;  
    break;  
   case EnumMousePointPosition.MouseSizeBottom:  
    lCtrl.Height = lCtrl.Height + e.Y - p1.Y;  
    p1.X=e.X;  
    p1.Y=e.Y; //'记录光标拖动的当前点  
    break;  
   case EnumMousePointPosition.MouseSizeBottomRight:  
    lCtrl.Width  = lCtrl.Width + e.X - p1.X;  
    lCtrl.Height = lCtrl.Height + e.Y - p1.Y;  
    p1.X=e.X;  
    p1.Y=e.Y; //'记录光标拖动的当前点  
    break;  
   case EnumMousePointPosition.MouseSizeRight:  
    lCtrl.Width  = lCtrl.Width + e.X - p1.X;     
//    lCtrl.Height = lCtrl.Height + e.Y - p1.Y;  
    p1.X=e.X;  
    p1.Y=e.Y; //'记录光标拖动的当前点  
    break;  
   case EnumMousePointPosition.MouseSizeTop:  
    lCtrl.Top  = lCtrl.Top + (e.Y - p.Y);  
    lCtrl.Height = lCtrl.Height - (e.Y - p.Y);  
    break;  
   case EnumMousePointPosition.MouseSizeLeft:  
    lCtrl.Left  = lCtrl.Left + e.X - p.X;  
    lCtrl.Width  = lCtrl.Width - (e.X - p.X);  
    break;  
   case EnumMousePointPosition.MouseSizeBottomLeft:  
    lCtrl.Left  = lCtrl.Left + e.X - p.X;  
    lCtrl.Width  = lCtrl.Width - (e.X - p.X);  
    lCtrl.Height = lCtrl.Height+ e.Y - p1.Y;  
    p1.X=e.X;  
    p1.Y=e.Y; //'记录光标拖动的当前点  
    break;  
   case EnumMousePointPosition.MouseSizeTopRight:  
    lCtrl.Top  = lCtrl.Top + (e.Y - p.Y);  
    lCtrl.Width  = lCtrl.Width + (e.X - p1.X);  
    lCtrl.Height = lCtrl.Height - (e.Y - p.Y);  
    p1.X=e.X;  
    p1.Y=e.Y; //'记录光标拖动的当前点  
    break;  
   case EnumMousePointPosition.MouseSizeTopLeft:  
    lCtrl.Left  = lCtrl.Left + e.X - p.X;  
    lCtrl.Top  = lCtrl.Top + (e.Y - p.Y);  
    lCtrl.Width  = lCtrl.Width - (e.X - p.X);  
    lCtrl.Height = lCtrl.Height - (e.Y - p.Y);  
    break;  
   default:  
    break;  
   }  
   if (lCtrl.Width<MinWidth) lCtrl.Width=MinWidth;  
   if (lCtrl.Height<MinHeight) lCtrl.Height=MinHeight;     
  
  }  
  else  
  {  
   m_MousePointPosition = MousePointPosition(lCtrl.Size, e);  //'判断光标的位置状态  
   switch (m_MousePointPosition)  //'改变光标  
   {  
   case EnumMousePointPosition.MouseSizeNone:  
    this.Cursor = Cursors.Arrow;    //'箭头  
    break;  
   case EnumMousePointPosition.MouseDrag:  
    this.Cursor = Cursors.SizeAll;   //'四方向  
    break;  
   case EnumMousePointPosition.MouseSizeBottom:  
    this.Cursor = Cursors.SizeNS;    //'南北  
    break;  
   case EnumMousePointPosition.MouseSizeTop:  
    this.Cursor = Cursors.SizeNS;    //'南北  
    break;  
   case EnumMousePointPosition.MouseSizeLeft:  
    this.Cursor = Cursors.SizeWE;    //'东西  
    break;  
   case EnumMousePointPosition.MouseSizeRight:  
    this.Cursor = Cursors.SizeWE;    //'东西  
    break;  
   case EnumMousePointPosition.MouseSizeBottomLeft:  
    this.Cursor = Cursors.SizeNESW;   //'东北到南西  
    break;  
   case EnumMousePointPosition.MouseSizeBottomRight:  
    this.Cursor = Cursors.SizeNWSE;   //'东南到西北  
    break;  
   case EnumMousePointPosition.MouseSizeTopLeft:  
    this.Cursor = Cursors.SizeNWSE;   //'东南到西北  
    break;  
   case EnumMousePointPosition.MouseSizeTopRight:  
    this.Cursor = Cursors.SizeNESW;   //'东北到南西  
    break;  
   default:  
    break;  
   }  
  }  
  
  }  

7、制作一个初始化html" target="_blank">过程，将界面panel1上的所有控件都绑定MyMouseDown、MyMouseLeave、MyMouseMove事件，记得在Form初始化或者Form_Load时先执行它。  

 private void initProperty()  
{  
 for(int i = 0; i < this.panel1.Controls.Count; i++)   
 {   
 this.panel1.Controls[i].MouseDown+= new System.Windows.Forms.MouseEventHandler(MyMouseDown);  
 this.panel1.Controls[i].MouseLeave+= new System.EventHandler(MyMouseLeave);  
 this.panel1.Controls[i].MouseMove += new System.Windows.Forms.MouseEventHandler(MyMouseMove);  
 }  
  
}  

8、ok，在运行之前你在panel1上放几个控件，执行程序，应该可以随便移动、改变其大小了 

C# WinForm控件的拖动和缩放的实现就此完成。 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持小牛知识库。