C#实现GDI+基本图的缩放、拖拽、移动

public Form1()//窗体构造函数
{
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);
}
}
///

/// 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
//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; }
    }