GDI + display image, crop, resize, transpose ...

In vs2017 dialog mode test by
a using namespace Gdiplus;
void CXXDlg :: the OnPaint ()
{
// the following two to add, or not display the picture, do not know why
CImage image1;
image1.Load (L "");
/ / display image
 the CDC the pDC * = the GetDC ();
 Graphics Graph (pDC-> GetSafeHdc ());
 image image (L "pic.jpg");

 graph.DrawImage (& image, 70, 50);
 the ReleaseDC (the pDC);

 // display image using a negative coordinate
 
 the CDC the pDC * = the GetDC ();
 Graphics Graph (pDC-> GetSafeHdc ());
 image image (L "pic.jpg");

 graph.DrawImage (& image, -70, -50);
 ReleaseDC (pDC);

 display resolution different picture of the situation //
 
 CDC * pDC = GetDC ();
 Graphics Graph (pDC-> GetSafeHdc ());
 Image Image (L "pic.jpg");

 graph.DrawImage (Image &, 0, 0); // draw the image

 CString strPrint; // output string
 double f = graph.GetDpiX () / image.GetHorizontalResolution (); // scaling

 strPrint.Format (L "screen resolution% .0f, the image resolution is% .0f, scaling is .1f%",
  graph.GetDpiX (), image.GetHorizontalResolution (), F);
 Graph .DrawString (strPrint, -1, & Font (L " bold",. 17, FontStyleBold),
  of PointF (0, 280), & SolidBrush with (Color :: Red));

 the ReleaseDC (the pDC);

 zooming method // image. 1
 
 the CDC * = the GetDC the pDC ();
 Graphics Graph (pDC-> GetSafeHdc ());

 CRect winRect;
 the GetClientRect (winRect); // get the window drawing area size

 Image image (L "pic.jpg") ;
 graph.DrawImage (& image, 0, 0 , winRect.Width (), winRect.Height ()); // draw the image

 the ReleaseDC (the pDC);
 
 // image scaling method 2
 
 the CDC the pDC * = the GetDC ();
 Graphics Graph ( pDC-> GetSafeHdc ());

 CRect winRect;
 the GetClientRect (winRect); // get the size of the window drawing area

 Rect rect (0, 0, winRect.Width (), winRect.Height ()); // Create a drawing area rectangular Object

 image image (L "pic.jpg");
 graph.DrawImage (& image, RECT); // draw the image

 the ReleaseDC (the pDC);

 ******************* ************************************************** *******
          6.4.4 Code
 ************************************** **************************************

 // trimming image display
 
 CDC * pDC = GetDC ( );
 Graph Graphics (pDC-> GetSafeHdc ());
 Image Image (L "pic.jpg");

 // start from an original image (12, 80), the trimming length 430, a width of the rectangular region 180
 // then displays it (80, 90) at
 graph.DrawImage (& image, 80, 90, 12 is, 80, 430., 180 [, UnitPixel);

 the ReleaseDC (the pDC);

 // scaling and cropping an image
 
 the CDC the pDC * = the GetDC ();
 Graphics Graph (pDC-> GetSafeHdc ());
 Image Image (L "pic.jpg");
 int = 430. nSrcWidth; // clip area width
 int nSrcHeight = 180; // clip area height
 // display a rectangular area configured
 destRect RECT (15, 40, (int) (* nSrcWidth 1.2), (int) (* nSrcHeight 1.2));

 graph.DrawImage (& Image, destRect, 12 is, 80, nSrcWidth, nSrcHeight, UnitPixel);

 the ReleaseDC (the pDC);

 // transpose images
 
 * = The GetDC the pDC the CDC ();
 Graphics Graph (pDC-> GetSafeHdc ());
 Bitmap Image (L "pic.jpg");

 
 // outputs the original image
 graph.DrawImage (Image &, 0, 0);

 // switch output image coordinate counter
 int nX = 500;
 int nY = 0;

 // image aspect
 int nWidth image.GetWidth = ();
 int = nHeight image.GetHeight ();

 Point Points [] = {// need to add the output position transposed image coordinate
  Point (nX, nY), // original position of the upper left corner of the image output
  Point (nX, nY + nWidth) , // output position upper right corner of the original image
  Point (nX + nHeight, nY) }; / / lower left corner of the original image output position

 graph.DrawImage (& image, Points,. 3);

 the ReleaseDC (the pDC);

 // mirror image of
 
 the CDC the pDC * = the GetDC ();
 Graphics Graph (pDC-> GetSafeHdc ());
 Image Bitmap (L "pic.jpg");
 
 // image aspect
 int nWidth image.GetWidth = ();
 int = nHeight image.GetHeight ();

 // horizontal position of the output image
 int nX = 0;
 int nY = 0 ;

 Point HoPoints [] = {
   Point (nWidth + nX, nY),   
   Point (nX, nY),     
   Point (nWidth + nX, nY + nHeight)};

 graph.DrawImage (& Image, HoPoints,. 3); // output level mirror

 // output position of the vertical mirror
 nX + = nWidth. 5;
 nY = 0;

 Point VePoints [] = {
  Point (nX, nY + nHeight),   
  Point (nWidth + nX, nY + nHeight),     
  Point (nX, nY) };

 graph.DrawImage (& Image, VePoints,. 3); // output vertical mirroring

 ReleaseDC (pDC);
 
 simple rotation of the image //
 
 the CDC the pDC * = the GetDC ();
 Graphics Graph (pDC-> GetSafeHdc ());
 Bitmap Image (L "pic.jpg");
 
 // image aspect
 int nWidth = image .GetWidth ();
 int = nHeight image.GetHeight ();

 // 90-degree rotation position of the output image
 int nX = 0;
 int nY = 0;

 Point points90 [] = {
   Point (nHeight + nX, nY),
   Point ( nHeight + nX, nY + nWidth),
   Point (nX, nY)};

 graph.DrawImage (& image, points90,. 3); // output image rotated by 90 degrees

 @ 180 degrees rotation of the image output position
 nX = nHeight + . 5;
 nY = 0;

 Point points180 [] = {
  Point (nWidth + nX, nY + nHeight),
  Point (nX, nY + nHeight),
  Point (nWidth + nX, nY)};

 graph.DrawImage (& Image, points180,. 3); // output image rotated by 180 degrees in

 the ReleaseDC (the pDC);

 // image distortion
 
 CDC the GetDC the pDC = * ();
 Graphics Graph (pDC-> GetSafeHdc ());
 Bitmap image (L "pic.jpg");
 
 // image aspect
 int nWidth image.GetWidth = ();
 int = nHeight image.GetHeight ( );

 // 1 warped image output position
 int nX = 0;
 int nY = 0;

 Point points1 [] = {
   Point (nX, nY),
   Point (nWidth + nX, nY + 0),
   Point (nX + 60, nHeight + nY)};

 graph.DrawImage (& image, points1,. 3); // output deformed figure 1

 // 2 position of the output image modification
 nX = 520;
 a = 0;

 Point points2 [] = {
  Point (nX + 52),
  Point (nX + 374 + 200),
  Point (nX + 117)};

 graph.DrawImage (& image, points2, 3); //输出变形图形2
}