iOS | 获取到图片的路径后，将图片保存到手机本地相册中

1.先获取到APP沙盒中的图片路径path
2.然后将path作为参数，传入下面的方法里，进行图片保存到手机本地相册中。

#pragma mark 将截取到的头像保存到本地相册
- (void)saveHeaderImageWith:(NSString *)path
{
    UIImage *img = [UIImage imageWithContentsOfFile:path];
    [self saveImageToPhotos:img];
}

#pragma mark 保存图片
- (void)saveImageToPhotos:(UIImage*)savedImage
{
    UIImageWriteToSavedPhotosAlbum(savedImage, self, @selector(image:didFinishSavingWithError:contextInfo:), NULL);
}

#pragma mark 系统的完成保存图片的方法
- (void)image: (UIImage *) image didFinishSavingWithError: (NSError *) error contextInfo: (void *) contextInfo
{
    NSString *msg = nil ;
    if (error != NULL) {
        msg = @"保存图片失败" ;
    } else {
        msg = @"保存图片成功" ;
    }
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"保存图片结果提示" message:msg delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil];
    [alert show];
}