#pragma mark - 保存至相册
- (void)saveImageToPhotoAlbum:(UIImage*)savedImage{
    UIImageWriteToSavedPhotosAlbum(savedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
}

//指定回调方法
- (void)image: (UIImage *)image didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo{
    if (image == nil) {
        return;
    }
    NSString *msg = @"保存图片成功";
    if(error != NULL){
        msg = @"保存图片失败" ;
    }
    NSLog(@"🌹🌹🌹🌹%@",msg);
}