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。
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