Request click menu options after using the mouse to draw a rectangle
I want to wait for the mouse give a starting point and end point after drawing, but drawing when using infinite loop control box would have been no response
How to solve it

//get the mouse start 
Void CtxxView: : OnLButtonDown (UINT nFlags, CPoint point) 
{
//TODO: add the message handler code and/or invoke the default 
This - & gt; SetCapture ();//to capture the mouse 
The StartPoint=point; 
The EndPoint=point; 
LButtonDown=true; 
The CView: : OnLButtonDown (nFlags, point); 
} 
//get the mouse at the end of the 
Void CtxxView: : OnLButtonUp (UINT nFlags, CPoint point) 
{
//TODO: add the message handler code and/or invoke the default 
ReleaseCapture ();//release the mouse 
The EndPoint=point; 
LButtonUp=true; 
The CView: : OnLButtonUp (nFlags, point); 
} 


Void CtxxView: : OnDrawRetectangle () 
{
//TODO: add the command handler code 
LButtonDown=LButtonUp=false; 
While (1) 
{
If (LButtonDown==true & amp; & LButtonUp==true) 
break; 
} 
The CDC * pDC=this - & gt; GetDC (); 
DDALine (pDC, the StartPoint. X, the StartPoint. Y, the EndPoint. X, the StartPoint. J y, RGB (255, 0, 0)); 
DDALine (pDC, EndPoint. X, the StartPoint. Y, the EndPoint. X, the EndPoint. The y, RGB (255, 0, 0)); 
DDALine (pDC, EndPoint. X, the EndPoint. Y, the StartPoint. X, the EndPoint. The y, RGB (255, 0, 0)); 
DDALine (pDC, the StartPoint. X, the EndPoint. Y, the StartPoint. X, the StartPoint. J y, RGB (255, 0, 0)); 


} 

CodePudding user response:

Should use a member variable in OnDrawRetectangle note click the map options, rather than write an infinite loop,
OnLButtonDown OnLButtonUp, record the start and end, respectively, and then to draw a rectangle in the OnLButtonUp,

Simple point so to try to modify:

 
//get the mouse start 
Void CtxxView: : OnLButtonDown (UINT nFlags, CPoint point) 
{
//TODO: add the message handler code and/or invoke the default 
This - & gt; SetCapture ();//to capture the mouse 
The StartPoint=point; 
The EndPoint=point; 
LButtonDown=true; 
The CView: : OnLButtonDown (nFlags, point); 
} 
//get the mouse at the end of the 
Void CtxxView: : OnLButtonUp (UINT nFlags, CPoint point) 
{
//TODO: add the message handler code and/or invoke the default 
ReleaseCapture ();//release the mouse 
The EndPoint=point; 
LButtonUp=true; 
The CView: : OnLButtonUp (nFlags, point); 

If (m_action==ActionDrawRect) {
//draw a rectangle 
The CDC * pDC=this - & gt; GetDC (); 
DDALine (pDC, the StartPoint. X, the StartPoint. Y, the EndPoint. X, the StartPoint. J y, RGB (255, 0, 0)); 
DDALine (pDC, EndPoint. X, the StartPoint. Y, the EndPoint. X, the EndPoint. The y, RGB (255, 0, 0)); 
DDALine (pDC, EndPoint. X, the EndPoint. Y, the StartPoint. X, the EndPoint. The y, RGB (255, 0, 0)); 
DDALine (pDC, the StartPoint. X, the EndPoint. Y, the StartPoint. X, the StartPoint. J y, RGB (255, 0, 0)); 
} 
} 

Void CtxxView: : OnDrawRetectangle () 
{
M_action=ActionDrawRect;//if defines the enumeration values ActionDrawRect menu options, what kind of behavior, using m_action to record the 
}