Void CDrawTrendDlg: : OnBtnQuery () {
Sleep (60 * 1000);//remove after normal display picture 
//MessageBox ("!" );//plus a messagebox, normal display picture 
//RedrawWindow ();//no impact 
CStatic * pDraw=(CStatic *) GetDlgItem (IDC_TREND_LINE); 
//pDraw - & gt; RedrawWindow ();//no impact 
CClientDC * pDC=new CClientDC (pDraw); 

CRect the rect. 
PDraw - & gt; GetClientRect (& amp; The rect); 
The rect. Bottom -=20; 
The rect. Left +=20; 

PDC - & gt; MoveTo (the rect. Left, the rect. Bottom); 
PDC - & gt; LineTo (the rect. Right, the rect. Bottom); 
//arrow to add 
PDC - & gt; MoveTo (the rect. Right - 5, the rect. Bottom - 5). 
PDC - & gt; LineTo (the rect. Right, the rect. Bottom); 
PDC - & gt; LineTo (the rect. Right - 5, the rect. Bottom + 5); 

PDC - & gt; MoveTo (the rect. Left, the rect. Bottom); 
PDC - & gt; LineTo (the rect. Left, the rect. Top); 
//arrow to add 
PDC - & gt; MoveTo (the rect. Left - 5, the rect. Top + 5); 
PDC - & gt; LineTo (the rect. Left, the rect. Top); 
PDC - & gt; LineTo (the rect. Left + 5, the rect. Top + 5); 

//custom coordinate system 
PDC - & gt; SetMapMode (MM_ANISOTROPIC); 
PDC - & gt; SetViewportOrg (the rect. Left, the rect. Bottom); 
PDC - & gt; SetWindowExt (5, the rect. Height ()); 
PDC - & gt; SetViewportExt (the rect. Width (), - the rect. Height ()); 

PDC - & gt; MoveTo (0, 0); 
Int xhor; 
Double yver; 

Int m=100; 
PDC - & gt; MoveTo (0, 0); 
for(int i=1; I & lt;=4; + + I) 
PDC - & gt; LineTo (I, m + I * 20); 
} 

The above code debugging, the image can also be normal, according to the runtime without image display, this is what causes, give advice or comments please everyone a great god?

CodePudding user response:

I glad to each master

CodePudding user response:

Why nobody answer

CodePudding user response:

What is used? The frequency of the call? What thread calls?

CodePudding user response:

CClientDC * pDC=new CClientDC (pDraw);

You are new, you delete??

CodePudding user response:

reference lhylhy reply: 3/f

cut with what? The frequency of the call? What thread calls?

There is only one main thread

CodePudding user response:

reference 4 floor draculamx response:

CClientDC * pDC=new CClientDC (pDraw);

You are new, you delete??

Here I copy only the part of the code, sorry miss, display and delete it doesn't matter

CodePudding user response:

May be drawing time is too long,