iOS实现视频下载并自动保存到相册功能

///@property (nonatomic,strong) MBProgressHUD *hud;

@property (nonatomic,strong) NSURLSession *session;
///视频播放和下载用的url 
@property (nonatomic,strong) NSURL *url;

///初始化session
- (NSURLSession *)session{
 if(_session == nil)
 {
 NSURLSessionConfiguration *config = [NSURLSessionConfiguration defaultSessionConfiguration];
 _session = [NSURLSession sessionWithConfiguration:config delegate:self delegateQueue:nil];
 }
 return _session;
}



///下载
- (void)download:(UIBarButtonItem *)btnItem{
 ///初始化Session
 _session = [XMConciseVedioPlayer getSession:_session];
 
 ///self.hud = [MBProgressHUD showHUDAddedTo:self animated:YES];
 
 [self downloadFileWithUrl:self.url];
 
}
///通过url下载
- (void)downloadFileWithUrl:(NSURL *)url{
 NSURLRequest *request = [NSURLRequest requestWithURL:url cachePolicy:1.0 timeoutInterval:5.0];
 ///下载任务
 [[self.session downloadTaskWithRequest:request]resume];
 
 NSURLSessionDownloadTask *task = [_session downloadTaskWithURL:url completionHandler:^(NSURL *location, NSURLResponse *response, NSError *error) {
 ///[self.hud setLabelText:[NSString stringWithFormat:@"下载成功"]];
 NSFileManager *fileManger = [NSFileManager defaultManager];
 ///沙盒Documents路径
 NSString *documents = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents"];
 //拼接文件绝对路径
 NSString *path = [documents stringByAppendingPathComponent:response.suggestedFilename];
 //视频存放到这个位置
 [fileManger moveItemAtURL:location toURL:[NSURL fileURLWithPath:path] error:nil];
 ///保存到相册
 UISaveVideoAtPathToSavedPhotosAlbum(path, self, @selector(video:didFinishSavingWithError:contextInfo:), nil);

 
 }];
 ///开始下载任务
 [task resume];
 
}

//保存视频完成之后的回调
- (void)video:(NSString *)videoPath didFinishSavingWithError:(NSError *)error contextInfo:(void *)contextInfo {
 if (!error) {
 ///[self.hud setLabelText:[NSString stringWithFormat:@"保存到相册成功"]];
 } else {
 ///[self.hud setLabelText:[NSString stringWithFormat:@"下载失败"]];
 }
 ///[self.hud hide:YES afterDelay:3.0];
}


// 进度数据
- (void)URLSession:(NSURLSession *)session downloadTask:(NSURLSessionDownloadTask *)downloadTask didWriteData:(int64_t)bytesWritten totalBytesWritten:(int64_t)totalBytesWritten totalBytesExpectedToWrite:(int64_t)totalBytesExpectedToWrite{
 float progress = (float)totalBytesWritten / totalBytesExpectedToWrite;
 long pro = (long)(progress *100);
 ///[self.hud setLabelText:[NSString stringWithFormat:@"下载进度:%ld%%",pro]];
}