C#中WinForm控制項的拖曳與縮放實作的程式碼分享

本篇文章主要介紹了C#中WinForm控制項的拖曳與縮放的實作程式碼，C# WinForm控制項的拖曳與縮放是個很有用的功能，有興趣的可以了解一下。

C# WinForm控制項的拖曳和縮放是個很有用的功能。實作起來其實很簡單的，主要是設計控制項的MouseDown、MouseLeave、MouseMove事件,下面的幾個步驟將逐步實作C# WinForm控制項的拖曳與縮放的功能。

1、定義一個枚舉類型，描述遊標狀態   

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、定義幾個變數  

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

3 、定義自己的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、定義自己的MyMouseLeave事件 

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

5、設計一個函數，確定遊標在控制項不同位置的樣式   

#

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、定義自己的MyMouseMove事件，在這個事件裡，會使用上面設計的函數   

  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);  //&#39;判断光标的位置状态  
   switch (m_MousePointPosition)  //&#39;改变光标  
   {  
   case EnumMousePointPosition.MouseSizeNone:  
    this.Cursor = Cursors.Arrow;    //&#39;箭头  
    break;  
   case EnumMousePointPosition.MouseDrag:  
    this.Cursor = Cursors.SizeAll;   //&#39;四方向  
    break;  
   case EnumMousePointPosition.MouseSizeBottom:  
    this.Cursor = Cursors.SizeNS;    //&#39;南北  
    break;  
   case EnumMousePointPosition.MouseSizeTop:  
    this.Cursor = Cursors.SizeNS;    //&#39;南北  
    break;  
   case EnumMousePointPosition.MouseSizeLeft:  
    this.Cursor = Cursors.SizeWE;    //&#39;东西  
    break;  
   case EnumMousePointPosition.MouseSizeRight:  
    this.Cursor = Cursors.SizeWE;    //&#39;东西  
    break;  
   case EnumMousePointPosition.MouseSizeBottomLeft:  
    this.Cursor = Cursors.SizeNESW;   //&#39;东北到南西  
    break;  
   case EnumMousePointPosition.MouseSizeBottomRight:  
    this.Cursor = Cursors.SizeNWSE;   //&#39;东南到西北  
    break;  
   case EnumMousePointPosition.MouseSizeTopLeft:  
    this.Cursor = Cursors.SizeNWSE;   //&#39;东南到西北  
    break;  
   case EnumMousePointPosition.MouseSizeTopRight:  
    this.Cursor = Cursors.SizeNESW;   //&#39;东北到南西  
    break;  
   default:  
    break;  
   }  
  }  
  
  }

7、製作一個初始化過程，將介面panel1上的所有控制項綁定MyMouseDown、MyMouseLeave 、MyMouseMove事件，記得在Form初始化或Form_Load時先執行它。

 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，在運行之前你在panel1上放幾個控件，執行程序，應該可以隨便移動、改變其大小了 

C# WinForm控件的拖曳和縮放的實現就此完成。 

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