C#实现GDI+基本图的缩放、拖拽、移动示例代码如下：
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
namespace ResizableControls
{
public partial class MainForm : Form
{
///
/// 有关鼠标样式的相关枚举
///
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
}
const int Band = 5;//范围半径
const int MinWidth = 10;//最低宽度
const int MinHeight = 10;//最低高度
private EnumMousePointPosition m_MousePointPosition; //鼠标样式枚举
private Point m_lastPoint; //光标上次移动的位置
private Point m_endPoint; //光标移动的当前位置
public MainForm()
{
InitializeComponent();
//窗体中控件的事件晚期绑定
for (int i = 0; i < this.Controls.Count; i++)
{
this.Controls[i].MouseDown += new MouseEventHandler(MyMouseDown);
this.Controls[i].MouseLeave += new EventHandler(MyMouseLeave);
this.Controls[i].MouseMove += new MouseEventHandler(MyMouseMove);
}
}
//鼠标按下事件
private void MyMouseDown(object sender,MouseEventArgs e)
{
m_lastPoint.X = e.X;
m_lastPoint.Y = e.Y;
m_endPoint.X = e.X;
m_endPoint.Y = e.Y;
}
//鼠标离开控件的事件
private void MyMouseLeave(object sender, System.EventArgs e)
{
m_MousePointPosition = EnumMousePointPosition.MouseSizeNone;
this.Cursor = Cursors.Arrow;
}
//鼠标移过控件的事件
private void MyMouseMove(object sender, MouseEventArgs e)
{
Control lCtrl = (sender as Control);//获得事件源
//左键按下移动
if (e.Button == MouseButtons.Left)
{
switch (m_MousePointPosition)
{
case EnumMousePointPosition.MouseDrag:
lCtrl.Left = lCtrl.Left + e.X - m_lastPoint.X;
lCtrl.Top = lCtrl.Top + e.Y - m_lastPoint.Y;
break;
case EnumMousePointPosition.MouseSizeBottom:
lCtrl.Height = lCtrl.Height + e.Y - m_endPoint.Y;
m_endPoint.X = e.X;
m_endPoint.Y = e.Y; //记录光标拖动的当前点 break;
case EnumMousePointPosition.MouseSizeBottomRight:
lCtrl.Width = lCtrl.Width + e.X - m_endPoint.X;
lCtrl.Height = lCtrl.Height + e.Y - m_endPoint.Y;
m_endPoint.X = e.X;
m_endPoint.Y = e.Y; //记录光标拖动的当前点 break;
case EnumMousePointPosition.MouseSizeRight:
lCtrl.Width = lCtrl.Width + e.X - m_endPoint.X;
//lCtrl.Height = lCtrl.Height + e.Y - m_endPoint.Y;
m_endPoint.X = e.X;
m_endPoint.Y = e.Y; //记录光标拖动的当前点
break;
case EnumMousePointPosition.MouseSizeTop:
lCtrl.Top = lCtrl.Top + (e.Y - m_lastPoint.Y);
lCtrl.Height = lCtrl.Height - (e.Y - m_lastPoint.Y); break;
case EnumMousePointPosition.MouseSizeLeft:
lCtrl.Left = lCtrl.Left + e.X - m_lastPoint.X;
lCtrl.Width = lCtrl.Width - (e.X - m_lastPoint.X); break;
case EnumMousePointPosition.MouseSizeBottomLeft:
lCtrl.Left = lCtrl.Left + e.X - m_lastPoint.X;
lCtrl.Width = lCtrl.Width - (e.X - m_lastPoint.X);
lCtrl.Height = lCtrl.Height + e.Y - m_endPoint.Y;
m_endPoint.X = e.X;
m_endPoint.Y = e.Y; //记录光标拖动的当前点
break;
case EnumMousePointPosition.MouseSizeTopRight:
lCtrl.Top = lCtrl.Top + (e.Y - m_lastPoint.Y);
lCtrl.Width = lCtrl.Width + (e.X - m_endPoint.X);
lCtrl.Height = lCtrl.Height - (e.Y - m_lastPoint.Y);
m_endPoint.X = e.X;
m_endPoint.Y = e.Y; //记录光标拖动的当前点 break;
case EnumMousePointPosition.MouseSizeTopLeft:
lCtrl.Left = lCtrl.Left + e.X - m_lastPoint.X;
lCtrl.Top = lCtrl.Top + (e.Y - m_lastPoint.Y);
lCtrl.Width = lCtrl.Width - (e.X - m_lastPoint.X);
lCtrl.Height = lCtrl.Height - (e.Y - m_lastPoint.Y);
break;
default:
break;
}
if (lCtrl.Width < MinWidth) lCtrl.Width = MinWidth;
if (lCtrl.Height < MinHeight) lCtrl.Height = MinHeight;
}
else
{
//'判断光标的位置状态
m_MousePointPosition = MousePointPosition(lCtrl.Size, e); 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;
}
}
}
//坐标位置判定
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; }
}
}
}