NSString *homePath = [NSSearchPathForDirectoriesInDomains(NSLibraryDirectory,NSUserDomainMask,YES) firstObject];
    NSString *path =[homePath stringByAppendingPathComponent:[url lastPathComponent]];
    __weak typeof(self) weakSelf = self;
    self.task = [self.downloader startDownloadFileTaskWithUrl:url toFilePath:path breakpointResume:YES progress:^(NSProgress * _Nonnull downloadProgress) {
        dispatch_async(dispatch_get_main_queue(), ^{
            weakSelf.progressView.progress = downloadProgress.fractionCompleted;
            self.progressLabel.text = [NSString stringWithFormat:@"%@",@(downloadProgress.fractionCompleted)];
        });
    } receivedBytes:^(long long receivedBytes) {
        
    } completionHandler:^(NSURLSessionTask * _Nonnull task, NSString * _Nullable filePath, NSError * _Nullable error) {
        if (!error) {
            dispatch_async(dispatch_get_main_queue(), ^{
                self.progressLabel.text = @"完成";
            });
        }
        [self.task cancel];
        self.task = nil;
        
    }];