iPhone開發之小技巧：圖片縮放（4）

static UIImage *shrinkImage(UIImage *original,CGSize size)
{
    CGFloat scale = [UIScreen mainScreen].scale;
    CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
    CGContextRef context = CGBitmapContextCreate(NULL, size.width*scale, size.height*scale, 8, 0, colorSpace, kCGImageAlphaPremultipliedFirst);
    CGContextDrawImage(context, CGRectMake(0, 0, size.width*scale, size.height*scale), original.CGImage);
    CGImageRef shrunken = CGBitmapContextCreateImage(context);
    UIImage *final = [UIImage imageWithCGImage:shrunken];
    
    CGContextRelease(context);
    CGImageRelease(shrunken);
    
    return  final;
}

內容很少，但是很實用，一滴一點積累起來！