截屏,裁剪图片，缩放图片

// 截屏
//       UIGraphicsBeginImageCont ext(self.view.frame.size);
//       [self.view.layer renderInContext:UIGraphicsGetCurrentCont ext()];
//       UIImage *viewImage = UIGraphicsGetImageFromCu rrentImageContext();
//       UIGraphicsEndImageContex t();
//       UIImageWriteToSavedPhoto sAlbum(viewImage, nil, nil, nil);


//  裁剪图片
-(UIImage *) cutFromImage:(UIImage *)image inRect:(CGRect)rect{
       CGImageRef sourceImageRef = [image CGImage];
       CGImageRef newImageRef = CGImageCreateWithImageIn Rect(sourceImageRef, rect);
       UIImage *newImage = [UIImage imageWithCGImage:newImageRef];
       return newImage;
}
// 缩放图片
- (UIImage *) scaleFromImage: (UIImage *) image toSize: (CGSize) size
{
       UIGraphicsBeginImageCont ext(size);
       [image drawInRect:CGRectMake(0, 0, size.width , size.height)];
       UIImage *newImage = UIGraphicsGetImageFromCu rrentImageContext();
       UIGraphicsEndImageContex t();
       return newImage;
}