public async void DownloadFileAsync() { var url = "https://www.baidu.com/img/baidu_jgylogo3.gif"; var filePath = @"d:\baidu_jgylogo3.gif"; File.Delete(filePath); var combiner = await _fileTransfer.DownloadFileAsync(url, filePath).ConfigureAwait(); Assert.NotNull(combiner); Assert.True(combiner.Exists()); combiner.Delete(); Assert.False(combiner.Exists()); }