iphone - UIImage到BitmapContext

我想将简单的UIImage转换为BitmapContext，但是找不到任何教程将UIImage转换为BitmapContext。请告诉我该怎么做？

谢谢!

最佳答案

可能这段代码可以帮助您

CGSize newSize = CGSizeMake(320, 400);
UIGraphicsBeginImageContext( newSize );

[imageView.image drawInRect:CGRectMake(0,0,newSize.width,newSize.height)];



UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();

UIGraphicsEndImageContext();

NSData * data = UIImagePNGRepresentation(newImage);
[data writeToFile:@"foo.png" atomically:YES];


 UIImageWriteToSavedPhotosAlbum(newImage, nil, nil, nil);///save image in phone

OR For Bitmap.

CGContextRelease(context);
context = CGBitmapContextCreate (NULL,
                                image.size.width,
                                image.size.height,
                                8,    // bits per component
                                bitmapBytesPerRow,
                                colorSpace,
                                kCGImageAlphaLast
                                );
CGColorSpaceRelease( colorSpace );

CGContextDrawImage(context, CGRectMake(0, 0, image.size.width, image.size.height), image.CGImage);
pixelData = CGBitmapContextGetData(context);