Question

我想在客户端区域使用鼠标进行4次点击。完成第4次点击后，应连接4个点以形成形状。我使用以下代码完成此操作。（我使用的是MFC）。

 void CChildView::OnLButtonDown(UINT nFlags,CPoint point)
 {
  CDC* pDC=GetDC();

   if(m_iPointCount==1)
 {
    m_FirstPoint.x=point.x;
    m_FirstPoint.y=point.y;
    pDC->TextOut(m_FirstPoint.x,m_FirstPoint.y,"1");
    rgn1.CreateEllipticRgn((m_FirstPoint.x-50),(m_FirstPoint.y-50),(m_FirstPoint.x+50),(m_FirstPoint.y+50));
}
if(m_iPointCount==2)
{
    m_SecondPoint.x=point.x;
    m_SecondPoint.y=point.y;
    pDC->TextOut(m_SecondPoint.x,m_SecondPoint.y,"2");
    rgn2.CreateEllipticRgn((m_SecondPoint.x-50),(m_SecondPoint.y-50),(m_SecondPoint.x+50),(m_SecondPoint.y+50));
}
if(m_iPointCount==3)
{
    m_ThirdPoint.x=point.x;
    m_ThirdPoint.y=point.y;
    pDC->TextOut(m_ThirdPoint.x,m_ThirdPoint.y,"3");
    rgn3.CreateEllipticRgn((m_ThirdPoint.x-50),(m_ThirdPoint.y-50),(m_ThirdPoint.x+50),(m_ThirdPoint.y+50));
}
if(m_iPointCount==4)
{
    m_FourthPoint.x=point.x;
    m_FourthPoint.y=point.y;
    pDC->TextOut(m_FourthPoint.x,m_FourthPoint.y,"4");
    rgn4.CreateEllipticRgn((m_FourthPoint.x-50),(m_FourthPoint.y-50),(m_FourthPoint.x+50),(m_FourthPoint.y+50));
    pDC->MoveTo(m_FirstPoint.x,m_FirstPoint.y);
    pDC->LineTo(m_SecondPoint.x,m_SecondPoint.y);
    pDC->LineTo(m_ThirdPoint.x,m_ThirdPoint.y);
    pDC->LineTo(m_FourthPoint.x,m_FourthPoint.y);
    pDC->LineTo(m_FirstPoint.x,m_FirstPoint.y);
}
m_iPointCount++;
}

每次点数增加。我还在4点左右创建了4个区域。我现在要做的是，当我点击我创建的任何区域并将其拖动到新位置时，该点应该移动到拖动后释放鼠标按钮的新位置。这样形状就改变了。这应该适用于所有4个地区。

我知道我必须使用Mousemove和LButtonUp函数，但我不知道该怎么做。请帮助。

Answer 1

嗨，我终于想出了如何做到这一点。

OnPaint事件如下：

void CChildView::OnPaint() 
{
CPaintDC dc(this); // device context for painting
{
    dc.MoveTo(m_FirstPoint.x,m_FirstPoint.y);
    dc.LineTo(m_SecondPoint.x,m_SecondPoint.y);
    dc.LineTo(m_ThirdPoint.x,m_ThirdPoint.y);
    dc.LineTo(m_FourthPoint.x,m_FourthPoint.y);
    dc.LineTo(m_FirstPoint.x,m_FirstPoint.y);   
}
}

LButtonDown如下：

void CChildView::OnLButtonDown(UINT nFlags,CPoint point)
{
CDC* pDC=GetDC();
if(m_iPointCount==1)
{
    m_FirstPoint.x=point.x;
    m_FirstPoint.y=point.y;
    pDC->TextOut(m_FirstPoint.x,m_FirstPoint.y,"1");
    rgn1.CreateEllipticRgn((m_FirstPoint.x-50),(m_FirstPoint.y-50),(m_FirstPoint.x+50),(m_FirstPoint.y+50));
}
if(m_iPointCount==2)
{
    m_SecondPoint.x=point.x;
    m_SecondPoint.y=point.y;
    pDC->TextOut(m_SecondPoint.x,m_SecondPoint.y,"2");
    rgn2.CreateEllipticRgn((m_SecondPoint.x-50),(m_SecondPoint.y-50),(m_SecondPoint.x+50),(m_SecondPoint.y+50));
}
if(m_iPointCount==3)
{
    m_ThirdPoint.x=point.x;
    m_ThirdPoint.y=point.y;
    pDC->TextOut(m_ThirdPoint.x,m_ThirdPoint.y,"3");
    rgn3.CreateEllipticRgn((m_ThirdPoint.x-50),(m_ThirdPoint.y-50),(m_ThirdPoint.x+50),(m_ThirdPoint.y+50));
}
if(m_iPointCount==4)
{
    m_FourthPoint.x=point.x;
    m_FourthPoint.y=point.y;
    pDC->TextOut(m_FourthPoint.x,m_FourthPoint.y,"4");
    rgn4.CreateEllipticRgn((m_FourthPoint.x-50),(m_FourthPoint.y-50),(m_FourthPoint.x+50),(m_FourthPoint.y+50));    
    InvalidateRect(0);
}
if(m_iPointCount>4)
{
    if(PtInRegion(rgn1,point.x,point.y))
    {
        m_fflag=true;
    }
    if(PtInRegion(rgn2,point.x,point.y))
    {
        m_sflag=true;
    }
    if(PtInRegion(rgn3,point.x,point.y))
    {
        m_tflag=true;
    }
    if(PtInRegion(rgn4,point.x,point.y))
    {
        m_foflag=true;
    }
   }
  m_iPointCount++;
  }

MouseMove如下：

  void CChildView::OnMouseMove(UINT nFlags,CPoint point)
  {
  if(m_iPointCount>4)
  if((nFlags & MK_LBUTTON)==MK_LBUTTON)
  {
    if(m_fflag==true)
    {
        m_FirstPoint=point;
        InvalidateRect(0);
    }
    if(m_sflag==true)
    {
        m_SecondPoint=point;
        InvalidateRect(0);
    }
    if(m_tflag==true)
    {
        m_ThirdPoint=point;
        InvalidateRect(0);
    }
    if(m_foflag==true)
    {
        m_FourthPoint=point;
        InvalidateRect(0);
    }
   }
   }

LButtonUp事件如下：

void CChildView::OnLButtonUp(UINT nFlags,CPoint point)
{
CDC* pDC=GetDC();
if(m_fflag==true)
{
    m_fflag=false;
    rgn1.DeleteObject();
    rgn1.CreateEllipticRgn((m_FirstPoint.x-50),(m_FirstPoint.y-50),(m_FirstPoint.x+50),(m_FirstPoint.y+50));
}
if(m_sflag==true)
{
    m_sflag=false;
    rgn2.DeleteObject();
    rgn2.CreateEllipticRgn((m_SecondPoint.x-50),(m_SecondPoint.y-50),(m_SecondPoint.x+50),(m_SecondPoint.y+50));
}
if(m_tflag==true)
{
    m_tflag=false;
    rgn3.DeleteObject();
    rgn3.CreateEllipticRgn((m_ThirdPoint.x-50),(m_ThirdPoint.y-50),(m_ThirdPoint.x+50),(m_ThirdPoint.y+50));
}
if(m_foflag==true)
{
    m_foflag=false;
    rgn4.DeleteObject();
    rgn4.CreateEllipticRgn((m_FourthPoint.x-50),(m_FourthPoint.y-50),(m_FourthPoint.x+50),(m_FourthPoint.y+50));
}
}

这是如何工作的：

1）整数m_iPointCount初始化为1.这用于存储点数。

2）最初将四个标志设置为假m_fflag = false; m_sflag = false; m_tflag = false; m_foflag = false;（四个标志对应多边形的四个点）。

3）当鼠标单击前4次时，4个点保存在m_Firstpoint，m_Secondpoint，m_Thirdpoint和m_Fourthpoint中。相应地创建了4个区域（rgn1，rgn2，rgn3，rgn4靠近4个点）。连接4个点以形成多边形。

4）当第五次点击时（在我们得到多边形之后），使用if条件进行检查以找出该点位于4个区域中的任何一个区域。因此标志设置为true 。（如果该点位于rgn1，则m_fflag设置为true，依此类推。）

5）考虑在rgn1中进行第5次单击，现在m_fflag为true，移动鼠标，此处更新用于在paint消息中绘制多边形的点，并使用InvalidateRect（0）调用paint方法。重绘了多边形.m_Firstpoint现在更新为新位置。

6）拖动后释放鼠标按钮时，标志设置为false，旧区域将被删除并在新点附近创建。因此该区域也会更新。

7）我已经解释了第一点，这适用于所有要点。

感谢。

使用鼠标移动点自定义形状

1 个答案: