There are only black and white after the BitBlt map-CodePudding

 
Void CMapData: : ReSize (int w, int h) 
{
If (w==Width& & H==Height) 
The return; 
The CDC myDC; 
CBitmap myMap, * oldmyMap; 
The CBrush b; 
Int ww=w> The Width? W: Width; 
Int hh=h> Height? H: the Height; 
MyDC. CreateCompatibleDC (& amp; PDC); 
MyMap. CreateCompatibleBitmap (& amp; PDC, ww, hh); 
OldmyMap=myDC. SelectObject (& amp; MyMap); 

Biggest reateSolidBrush (RGB (0,0,255)); 
MyDC. FillRect (CRect (0, 0, ww, hh), & amp; B); 
MyDC. BitBlt (0, 0, Width, Height, & amp; PDC, 0, 0, SRCCOPY);/////backup of the current drawing 


PDC. SelectObject (oldmap); 
The map. The DeleteObject (); 

Map. CreateCompatibleBitmap (& amp; PDC, w, h); 
Oldmap=pDC. SelectObject (& amp; The map); 

PDC. BitBlt (0, 0, w, h, & amp; MyDC, 0, 0, SRCCOPY);///back to the new size of the bitmap; 

Width=w; 
Height=h; 
MyDC. SelectObject (oldmyMap); 
MyDC. DeleteDC (); 
MyMap. DeleteObject (); 
B.D eleteObject (); 

OldPoint=newPoint=CPoint (1, 1); 

}

CodePudding user response:

Aunt consult everybody, in the code not found what's the problem, after the paste only black and white, the color of the original image,

CodePudding user response:

CClientDC myDC (this);

CodePudding user response:

This function just want to realize the current pDC on the size of the map, including pDC, the map is initialized,

CodePudding user response:

 
Virtual BOOL CreateCompatibleDC (pDC) CDC *; 

The Return Value 

Nonzero if the function is successful; Otherwise 0. 

The Parameters 

PDC 

A pointer to A device context. If pDC is NULL, the function creates A memory device context that is compatible with the system display. 

Few 

Creates a memory device context that is compatible with the device specified by pDC. A memory device context is a block of memory that represents a display surface. It can be 2 prepare images in memory before copying them to the actual device surface of the compatible device. 

When a memory device context is created, GDI automatically selects a 1 - by - 1 monochrome stock bitmap for it. The GDI output functions provides can be 2 with a memory device context only if a bitmap has had created and selected into that context.

When a memory device context is created, GDI automatically selects a 1 - by - 1 monochrome stock bitmap for it.

CodePudding user response:

Don't understand, you mean I don't need to choose a MyMap MyDC?

CodePudding user response:

Such as

 
Void CLeftView: : ontouch * pDC (CDC) 
{
CVC60Doc * pDoc=GetDocument (); 
ASSERT_VALID (pDoc); 
//
If (pDoc - & gt; GetLeftBitmap ())//m_hBmpLeft) 
{//not client the rect only! 
The SIZE of sz=GetTotalSize (); 
Sz. Cx -=10;//gap 
Sz. Cy -=10; 
The CDC memDC; 
MemDC. CreateCompatibleDC (pDC); 
HBITMAP hOldBitmap=(HBITMAP) memDC. SelectObject (pDoc - & gt; GetLeftBitmap ());//m_hBmpLeft); 
PDC - & gt; BitBlt (4, 4, sz. Cx, sz, cy, & amp; MemDC, 0, 0, SRCCOPY);//may bigger then client 
MemDC. SelectObject (hOldBitmap); 
} 
The else 
{
PDC - & gt; TextOut (10, 10, "the Open 24 bits of a bitmap!" ); 
} 
}

Void CLeftView: : ontouch (pDC) CDC *//this color dc dc is

The CDC memDC;
MemDC. CreateCompatibleDC (pDC);//this is color dc dc

CodePudding user response:

Wanted to ask you is that pDC is global, please a memdc, I also met the Pal how broken?