UIImage BitmapContext

Question

我想將一個簡單的UIImage轉換爲BitmapContext，但我找不到任何教程將UIImage轉換爲BitmapContext。請告訴我該怎麼做？

謝謝！

Answer 1

可能是這段代碼可以幫助您

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);