使用Win32显示位图时出错 [英] Error Displaying Bitmap using Win32

问题描述

您好我正在尝试显示图像&使用win32应用程序在我的窗口中旋转并显示它。参考文献[ http：//www.codeguru。 com / cpp / gm / bitmap / specialeffects / article.php / c1743 / Rotate-a-bitmap-image.htm [ ^ ]



我的问题是图像显示为单色图像&不是彩色图像。否则此绘图操作无法返回true或false。

任何人都可以在我的代码中指出错误吗？



谢谢

问候，

Balaji.R

 HBITMAP GetRotatedBitmap（HWND hWnd，HBITMAP hBitmapSource， float  radians）
 {
 radians =（ 2  *  3  。 14567  *弧度）/ 360; 
 HDC sourceDC，destDC; 
 
 sourceDC = CreateCompatibleDC（NULL）; 
 destDC = CreateCompatibleDC（NULL）; 
 
 
 COLORREF clrBack =  0 ; 
 
  //  获取逻辑坐标 
 BITMAP bm; 
 GetObject（hBitmapSource， sizeof （bm），& bm）; 
 
  float  cosine =（ float ）cos（弧度）; 
  float  sine =（ float ）sin（弧度）; 
 
  //  计算结果位图的尺寸 
  //  首先获取除原点以外的3个角的坐标 
  int  x1 =（ int ）（bm.bmHeight * sine）; 
  int  y1 =（ int ）（bm.bmHeight * cosine）; 
  int  x2 =（ int ）（bm.bmWidth * cosine + bm.bmHeight * sine ）; 
  int  y2 =（ int ）（bm.bmHeight * cosine  -  bm.bmWidth * sine ）; 
  int  x3 =（ int ）（bm.bmWidth * cosine）; 
  int  y3 =（ int ）（ -  bm.bmWidth * sine）; 
 
  int  minx = min（ 0 ，min（x1，min（x2） ，X3）））; 
  int  miny = min（ 0 ，min（y1，min（y2，y3）） ）; 
  int  maxx = max（ 0 ，max（x1，max（x2，x3）） ）; 
  int  maxy = max（ 0 ，max（y1，max（y2，y3）） ）; 
 
  int  w = maxx  -  minx; 
  int  h = maxy  -  miny; 
 
  //  创建一个位图来保存结果 
 HBITMAP hbmResult = CreateCompatibleBitmap（destDC，w，h）; 
 HBITMAP hbmOldSource =（HBITMAP）SelectObject（sourceDC，hBitmapSource）; 
 HBITMAP hbmOldDest =（HBITMAP）SelectObject（destDC，hbmResult）; 
 
  //  在我们更改映射模式之前绘制背景颜色 
 HBRUSH hbrBack = CreateSolidBrush（clrBack）; 
 HBRUSH hbrOld =（HBRUSH）SelectObject（destDC，hbrBack）; 
 PatBlt（destDC， 0 ， 0 ，w，h，SRCCOPY）; 
 DeleteObject（hbrOld）; 
 
  //  我们将使用世界变换来旋转位图 
 SetGraphicsMode（destDC，GM_ADVANCED）; 
 XFORM xform; 
 xform.eM11 =余弦; 
 xform.eM12 = -sine; 
 xform.eM21 =正弦; 
 xform.eM22 =余弦; 
 xform.eDx =（ float ） -  minx; 
 xform.eDy =（ float ） -  miny; 
 
 SetWorldTransform（destDC，& xform）; 
 
 BitBlt（destDC， 0 ， 0 ，bm.bmWidth，bm。 bmHeight，sourceDC， 0 ， 0 ，SRCCOPY）;  / /  最后，绘制它 
 
 SelectObject（sourceDC，hbmOldSource）; 
 SelectObject（destDC，hbmOldDest）; 
  return  hbmResult; 
} 
 
  void  DrawImageWindow（HWND hWnd， float  angle） 
 {
 HDC hDC = GetWindowDC（hWnd）; 
 HBITMAP hBitmapDestination; 
 HBITMAP hBitmapSource =（HBITMAP）LoadImage（NULL，L   SourceImage.bmp，IMAGE_BITMAP ， 0 ， 0 ，LR_LOADFROMFILE | LR_CREATEDIBSECTION）; 
 
 hBitmapDestination =（HBITMAP）GetRotatedBitmap（hWnd，hBitmapSource，angle）; 
 
 BITMAP BMP; 
 GetObject（hBitmapDestination， sizeof （BMP），& BMP）;  //  这里我们得到BMP标题信息。 
 
 
 HDC BMPDC = CreateCompatibleDC（NULL）;  //  这将保留BMP图像本身。 
 
 
 SelectObject（BMPDC，hBitmapDestination）;  //  将图像放入DC。 
 
 BitBlt（hDC，< span class =code-digit> 0 ， 0 ，BMP.bmWidth，BMP.bmHeight，BMPDC， 0 ， 0 ，SRCCOPY）;  //  最后，绘制它 
 
 ReleaseDC（hWnd，hDC）; 
 
  //  别忘了清理！ 
 DeleteDC（BMPDC）; 
 DeleteObject（hBitmapSource）; 
 DeleteObject（hBitmapDestination）; 
} 
 LRESULT CALLBACK WndProc（HWND hWnd，UINT消息，WPARAM wParam，LPARAM lParam）
 {
 ... 
  case  WM_PAINT：
 hdc = BeginPaint（hWnd，& ps）; 
 DrawImageWindow（hWnd，angle）; 
 EndPaint（hWnd，& ps）; 
  break ; 
 .... 
} 

解决方案

我通过更改此行修复了此错误。

HBITMAP hbmResult = CreateCompatibleBitmap（destDC，w，h）;

to

HBITMAP hbmResult = CreateCompatibleBitmap（GetDC（NULL），w，h）; / /

Hi i am trying to display a Image & Rotate and Display it in my window using win32 application. Ref[http://www.codeguru.com/cpp/g-m/bitmap/specialeffects/article.php/c1743/Rotate-a-bitmap-image.htm[^]

My problem is the Image is appearing as a Monochrome Image & not a color Image. Otherwise this drawing operation fails returning true or false.
Could anyone please point the bug in my code?

Thank you
Regards,
Balaji.R

HBITMAP GetRotatedBitmap( HWND hWnd,HBITMAP hBitmapSource, float radians)
{	
	radians = (2 * 3.14567 *radians)/360;
	HDC sourceDC, destDC;

	sourceDC = CreateCompatibleDC(NULL);
	destDC = CreateCompatibleDC(NULL);
	 

	COLORREF clrBack=0;

	// Get logical coordinates
    BITMAP bm;
	GetObject(hBitmapSource,sizeof( bm ), &bm );
	
	float cosine = (float)cos(radians);
	float sine = (float)sin(radians);
 		
	// Compute dimensions of the resulting bitmap
	// First get the coordinates of the 3 corners other than origin
	int x1 = (int)(bm.bmHeight * sine);
	int y1 = (int)(bm.bmHeight * cosine);
	int x2 = (int)(bm.bmWidth * cosine + bm.bmHeight * sine);
	int y2 = (int)(bm.bmHeight * cosine - bm.bmWidth * sine);
	int x3 = (int)(bm.bmWidth * cosine);
	int y3 = (int)(-bm.bmWidth * sine);
 
	int minx = min(0,min(x1, min(x2,x3)));
	int miny = min(0,min(y1, min(y2,y3)));
	int maxx = max(0,max(x1, max(x2,x3)));
	int maxy = max(0,max(y1, max(y2,y3)));
 
	int w = maxx - minx;
	int h = maxy - miny;
			
	// Create a bitmap to hold the result
	HBITMAP hbmResult = CreateCompatibleBitmap(destDC, w, h);	     
	HBITMAP hbmOldSource = (HBITMAP)SelectObject( sourceDC, hBitmapSource );	
    HBITMAP hbmOldDest = (HBITMAP)SelectObject( destDC, hbmResult );
     
	// Draw the background color before we change mapping mode
    HBRUSH hbrBack = CreateSolidBrush( clrBack );
    HBRUSH hbrOld = (HBRUSH)SelectObject( destDC, hbrBack );
	PatBlt(destDC,0,0, w, h, SRCCOPY );
    DeleteObject(hbrOld);

	// We will use world transform to rotate the bitmap
	SetGraphicsMode(destDC, GM_ADVANCED);
	XFORM xform;
	xform.eM11 = cosine;
	xform.eM12 = -sine;
	xform.eM21 = sine;
	xform.eM22 = cosine;
	xform.eDx = (float)-minx;
	xform.eDy = (float)-miny;
 
	SetWorldTransform( destDC, &xform );
		
	BitBlt(destDC, 0, 0,bm.bmWidth, bm.bmHeight,sourceDC, 0, 0, SRCCOPY );// Finally, Draw it
   	
	SelectObject( sourceDC, hbmOldSource );
    SelectObject( destDC, hbmOldDest );	
	return hbmResult;
}

void DrawImageWindow(HWND hWnd,float angle)
{
	HDC hDC = GetWindowDC(hWnd);
	HBITMAP hBitmapDestination;	
	HBITMAP hBitmapSource = (HBITMAP)LoadImage(NULL, L"SourceImage.bmp", IMAGE_BITMAP,0, 0, LR_LOADFROMFILE | LR_CREATEDIBSECTION);
	
	hBitmapDestination = (HBITMAP)GetRotatedBitmap(hWnd,hBitmapSource,angle);

	BITMAP BMP;
	GetObject(hBitmapDestination, sizeof(BMP), &BMP); // Here we get the BMP header info.


	HDC BMPDC = CreateCompatibleDC(NULL); // This will hold the BMP image itself.

	
	SelectObject(BMPDC, hBitmapDestination); // Put the image into the DC.

	BitBlt(hDC, 0, 0, BMP.bmWidth, BMP.bmHeight, BMPDC, 0, 0, SRCCOPY); // Finally, Draw it

	ReleaseDC(hWnd,hDC);

	// Don't forget to clean up!
	DeleteDC(BMPDC);	
	DeleteObject(hBitmapSource);
	DeleteObject(hBitmapDestination);
}
LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	...
	case WM_PAINT:        
			hdc = BeginPaint(hWnd, &ps);		
			DrawImageWindow(hWnd,angle);
			EndPaint(hWnd, &ps);
			break;
	....
}

解决方案

I have fixed this bug by changing this line.
HBITMAP hbmResult = CreateCompatibleBitmap(destDC, w, h);
to
HBITMAP hbmResult = CreateCompatibleBitmap(GetDC(NULL), w, h);//

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