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脚本之家。

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