Question

以下单元测试失败：

[TestMethod]
public void Add_file_to_blob_and_retrieve_it()
{
    var blobName = Guid.NewGuid().ToString();
    var testFileContents = File.ReadAllText(TestFileSpec);

    Trace.WriteLine(string.Format("Opening blob container {0}", UnitTestBlobAgentName));
    CloudStorageAccount.SetConfigurationSettingPublisher(
            (configName, configSetter) => configSetter(ConfigurationManager.AppSettings[configName]));
    var cloudStorage = CloudStorageAccount.FromConfigurationSetting("StorageConnectionString");
    var blobClient = cloudStorage.CreateCloudBlobClient();
    var container = blobClient.GetContainerReference(UnitTestBlobAgentName.ToLower());

    try
    {
        Trace.WriteLine(string.Format("Uploading file {0}", TestFileSpec));
        var blob = container.GetBlobReference(blobName);
        blob.UploadFile(TestFileSpec);
        blob.Properties.ContentType = "ByteArray";
        blob.SetProperties();
        var blob1 = container.GetBlobReference(blobName);
        var found = blob1.DownloadText();
        Assert.AreEqual(testFileContents.Trim(), found.Trim());
    }
    finally
    {
        if (null != container)
        {
            Trace.WriteLine(string.Format("Deleting blob {0}", blobName));
            var blob2 = container.GetBlobReference(blobName);
            blob2.DeleteIfExists(new BlobRequestOptions { DeleteSnapshotsOption = DeleteSnapshotsOption.IncludeSnapshots });
        }
    }
}

事实证明，返回的字符串以dword 0xFEFF（Unicode BOM）开头。我已经跟踪了Microsoft调试符号，并且BOM存在于返回流中。 AFAICT，它来自HttpResponse.GetResponseStream()类中的Microsoft.WindowsAzure.StorageClient.CloudBlob方法调用方式。

确保输入和输出完全相同的最佳方法是什么？在进入之前确保输入转换为Unicode？从输出中剥离BOM？还有其他想法吗？

Answer 1

这是一个旧的，但如果您的blob在azure中编码为Unicode，并且您想将其下载到文本字符串，则此代码将起作用。请记住，这里的弱点是你必须分配两次内存。如果有一种更有效的方法来获取Unicode字符串（无论如何同步），我找不到它。

string fileText;
using (var memoryStream = new MemoryStream())
{
    cloudBlob.DownloadToStream(memoryStream);

    memoryStream.Position = 0;

    using (var reader = new StreamReader(memoryStream, Encoding.Unicode))
    {
        fileText = reader.ReadToEnd();
    }
}

CloudBlob.DownloadText方法是否会插入其他字符？

1 个答案: