将拖拽进行到底

问题描述：
　　想在.Net下实现对一些非规则窗体，没有Caption，FormBorderStyle = System.Windows.Forms.FormBorderStyle.None;窗体的拖拽，最小化，最大化，特殊操作的实现(如图1所示)。在黄色的区域即区域1里实现对窗体的拖拽操作，在橙色区域即区域2里实现对窗体的最小化操作，在蓝色区域即区域3里实现对窗体的关闭操作，在绿色区域即区域4里实现对窗体的特殊操作(如双倍窗体)。

　　　(图1)

问题实现：
第一种方法　添加Label为Label添加Click事件。(如图2所示)
如果要用这种方法实现，就要为每一个颜色区域进行切图，并要保证有正确的切图长和宽，然后设置Label的背景为这个图片。

　　　(图2)
处理他们的Click事件，拖拽处理MouseDown MouseUp事件。
  第二中方法　不添加Label只处理鼠标事件，判断鼠标的位置然后决定执行什么操作，这种方法很耗费资源，每次鼠标点击就要判断，鼠标是否在某个区域然后决定是否要处理。不过这个处理用多态包装了。程序看起来比较整齐。
//定义常量
    private Point point;
    private const int dragMove=172;
    private const int dragMin=72;
    private const int dragClose=72;
    private const int dragDouble=78;
    private const int dragHeight=29;
    private MouseHandleEnum dragEnum;

//定义MouseDown事件
private void DragMain_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
    {
      point.X=e.X;
      point.Y=e.Y;
      if(e.Y<dragHeight)
      {
        if(e.X<dragMove)
        {
          dragEnum = MouseHandleEnum.Move;
          return;
        }
        if(e.X<dragMove+dragMin)
        {
          dragEnum = MouseHandleEnum.Min;
          return;
        }
        if(e.X<dragMove+dragMin+dragClose)
        {
          dragEnum = MouseHandleEnum.Close;
          return;
        }
        if(e.X<dragMove+dragMin+dragClose+dragDouble)
        {
          dragEnum = MouseHandleEnum.Double;
          return;
        }
      }

    }


//定义MouseUp事件
private void DragMain_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
    {
      point.X=e.X-point.X;
      point.Y=e.Y-point.Y;
      IDragMouse idragMouse;
      switch(dragEnum)
      {
        case MouseHandleEnum.Move :
          idragMouse = new MouseMove(point,this);
          break;
        case MouseHandleEnum.Min :
          idragMouse = new MouseMin(point,this);
          break;
        case MouseHandleEnum.Close :
          idragMouse = new MouseClose(point,this);
          break;
        case MouseHandleEnum.Double :
          idragMouse = new MouseDouble(point,this);
          break;
        default:
          idragMouse = null;
          break;
      }
      if(idragMouse!=null)
        idragMouse.MouseDo();
    }
  }
//定义基类
namespace DragMouse
{
public enum MouseHandleEnum
{
   None=0,
   Move=1,
   Min=2,
   Close=3,
   Double=4,
}
public class DragMouseBase
  {
    protected Point point;
    public Form form;
    public DragMouseBase(Point point, Form form)
    {
      this.point = point;
      this.form = form;
    }
  }
}
//定义接口
namespace DragMouse
{
  /// <summary>
  ///
  /// </summary>
  public interface IDragMouse
  {
    void MouseDo();
  }
}
//拖拽操作
namespace DragMouse
{
  /// <summary>
  ///
  /// </summary>
  public class MouseClose : DragMouseBase,IDragMouse
  {
    public MouseClose(Point point,Form form):base(point,form)
    {
      //
      // TODO: Add constructor logic here
      //
    }
    #region IDragMouse Members

    public void MouseDo()
    {
      Application.Exit();
      // TODO: Add MouseClose.MouseDo implementation
    }

    #endregion
  }
}
//其他操作类似。
  第三种方法　是用责任链这个设计模式来包装鼠标的点击操作，把操作分配到各个责任链的节点上，是程序更加面向对象，有更好的扩展性。

//两个鼠标事件
private void DragMain_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e)
    {
      request.GetInformation(e.X,e.Y);

    }

private void DragMain_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e)
    {
      request.SetScreenPoint(e.X,e.Y);

    }

//封装的请求类
  public class Request
  {
    public int iScreenX;
    public int iScreenY;

    public int eX;
    public int eY;

    public readonly int yHigh;
    public readonly int dragLength;
    public readonly int minLength;
    public readonly int closeLength;
    public readonly int doubleLength;

    private DragHandler dragHandler;
    private MinHandler minHandler;
    private CloseHandler closeHandler;
    private DoubleHandler doubleHandler;

    public Form parentForm;

    public void SetScreenPoint(int iX,int iY)
    {
      iScreenX = iX;
      iScreenY = iY;
      dragHandler.HandleRequest(this);
    }

    public void GetInformation(int ex,int ey)
    {
      eX=ex;
      eY=ey;
    }

    public Request(int yhigh,int draglength,Form form)
    {
      yHigh = yhigh;
      dragLength = draglength;
      parentForm = form;
      dragHandler = new DragHandler();
      minHandler =new MinHandler();
      closeHandler = new CloseHandler();
      doubleHandler = new DoubleHandler();

      dragHandler.SetSuccessor(minHandler);
      minHandler.SetSuccessor(closeHandler);
      closeHandler.SetSuccessor(doubleHandler);
    }


public Request(int yhigh,int draglength,int minlength,Form form):this(yhigh,draglength,form)
    {
      minLength = minlength;
    }


public Request(int yhigh,int draglength,int minlength,int closelength,Form form):this(yhigh,draglength,minlength,form)
    {
      closeLength = closelength;
    }


public Request(int yhigh,int draglength,int minlength,int closelength, int doublelength , Form form):this(yhigh,draglength,minlength,closelength,form)
    {
      doubleLength = doublelength;
    }

  }
//拖拽操作
  public class DragHandler : Handler
  {
    override public void HandleRequest(Request request)
    {
      // determine if we can handle the request
      if ((request.eY<request.yHigh)&&(request.eX<request.dragLength)) // some complex decision making!
      {
        request.parentForm.Left += request.iScreenX-request.eX;
        request.parentForm.Top += request.iScreenY-request.eY;

        // request handling code goes here
      }
      else
      {
        // not handled here - pass on to next in the chain
        if (successorHandler != null)
          successorHandler.HandleRequest(request);
      }
    }
  }
//其他操作类似

  第四种方法　（只是有想法还没有找到成功的实现办法）
  在MFC中可以用PostMessage或者SendMessag发消息，当鼠标单击，但不在窗体的CaptionTitle上时，发一个消息告诉系统鼠标在CaptionTitle（每个窗口自己TitleBar）上，这样窗口的拖拽就可以由系统托管了。现在实现了在窗口中任意位置单击鼠标拖拽窗体。但是没有实现上面要求的那些多样化操作。

  if(point.y<this->m_Height)
  {
//发消息给系统伪装鼠标在Caption Bar 上。
    if(point.x<this->m_Drag)
    {
      PostMessage(WM_NCLBUTTONDOWN,
        HTCAPTION,
        MAKELPARAM(point.x,point.y));
      return;
    }
    if(point.x<this->m_Drag+this->m_Min&&point.x>this->m_Drag)
    {
      PostMessage(WM_NCLBUTTONDOWN,
        HTMINBUTTON,
        MAKELPARAM(point.x,point.y));
      return;
    }
    if(point.x<this->m_Drag+this->m_Min+this->m_Close&&point.x>this->m_Drag+this->m_Min)
    {
      PostMessage(WM_NCLBUTTONDOWN,
        HTCLOSE,
        MAKELPARAM(point.x,point.y));
      return;
    }
    if(point.x<this->m_Drag+this->m_Min+this->m_Close+this->m_Double&&point.x>this->m_Drag+this->m_Min+this->m_Close)
    {
      CRgn *rgn = new CRgn();
      CRect *rect =new CRect();
      this->GetWindowRect(*rect);
      this->SetWindowRgn(*rgn,true);
      return;
    }

  }
　　遗憾
第四种方法是效率最高的，但是没有完全搞出来。
本文所有事例程序在中文WindowsXp Sp2 + VC7 下编译通过

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