// 等比例缩放图片/**    方法作用：按比例缩放,size 是你要把图显示到 多大区域    参数：    sourceImage: 图片UIImage    targetSize: 缩放宽高        调用：    UIImage *newImage = [self imageCompressFitSizeScale:image targetSize:CGSizeMake(200, 300)]; */- (UIImage *) imageCompressFitSizeScale:(UIImage *)sourceImage targetSize:(CGSize)size{    UIImage *newImage = nil;    CGSize imageSize = sourceImage.size;    CGFloat width = imageSize.width;    CGFloat height = imageSize.height;    CGFloat targetWidth = size.width;    CGFloat targetHeight = size.height;    CGFloat scaleFactor = 0.0;    CGFloat scaledWidth = targetWidth;    CGFloat scaledHeight = targetHeight;    CGPoint thumbnailPoint = CGPointMake(0.0, 0.0);        if(CGSizeEqualToSize(imageSize, size) == NO){                CGFloat widthFactor = targetWidth / width;        CGFloat heightFactor = targetHeight / height;                if(widthFactor > heightFactor){            scaleFactor = widthFactor;        }        else{            scaleFactor = heightFactor;        }        scaledWidth = width * scaleFactor;        scaledHeight = height * scaleFactor;                if(widthFactor > heightFactor){            thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;        }else if(widthFactor < heightFactor){            thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;        }    }    UIGraphicsBeginImageContext(size);        CGRect thumbnailRect = CGRectZero;    thumbnailRect.origin = thumbnailPoint;    thumbnailRect.size.width = scaledWidth;    thumbnailRect.size.height = scaledHeight;        [sourceImage drawInRect:thumbnailRect];        newImage = UIGraphicsGetImageFromCurrentImageContext();    if(newImage == nil){        NSLog(@"scale image fail");    }        UIGraphicsEndImageContext();    return newImage;}