<11>改变图像的尺寸，方便上传服务器

 *改变图像的尺寸，方便上传服务器
 * &-image 待传入UIImage
 * &-size 待传入UIImage要改变图像的尺寸
 * 返回处理好的UIImage
 */

+ (UIImage *)scaleFromImage:(UIImage *)image toSize:(CGSize)size;

/**
 * 改变图像的尺寸，方便上传服务器
 */
+ (UIImage *) scaleFromImage: (UIImage *) image toSize: (CGSize) size
{
    UIGraphicsBeginImageContext(size);
    [image drawInRect:CGRectMake(0, 0, size.width, size.height)];
    UIImage *newImage = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return newImage;

}