c# - 与Azure存储异步创建Blob时发生异常-UploadTextAsync

在我们的项目中，我们使用的是Azure Storage 6.0.0版本，并且使用UploadTextAsync方法创建Blob。更新到最新版本后，UploadTextAsync函数停止工作，现在引发异常：


  “你调用的对象是空的。”


我尝试了不同的方法来替换它，但是都抛出相同的异常。例如：

byte[] fileBytes = Encoding.UTF8.GetBytes(data);
await lockBlob.UploadFromByteArrayAsync(fileBytes, 0, fileBytes.Length);

使它起作用的唯一方法是更改​​为同步版本：

BlobRequestOptions blobOptions = new BlobRequestOptions
{
         MaximumExecutionTime = TimeSpan.FromSeconds(5),
};
lockBlob.UploadText(data, null, null, blobOptions, null);

如何使异步版本正常工作？有解决方法吗？我真的需要异步版本。

如果不存在，则UploadText（异步和同步）方法将创建该Blob，如果存在，则将其覆盖。

为什么它与同步版本一起使用而不与更新异步？

对于Blob创建，代码如下：

var container= client.GetContainerReference("lockblobs");
await container.CreateIfNotExistsAsync();
var lockBlob = container.GetBlockBlobReference(data);

最佳答案

解决了：

通过Azure包内的调用堆栈进行调试后，事实证明BlobRequestOptions中存在检查，默认情况下，RequireEncryption和EncryptionPolicy之间不匹配。

这是BlobRequestOptions定义内的元凶：

internal void AssertPolicyIfRequired()
{
    if (this.RequireEncryption.HasValue && this.RequireEncryption.Value && this.EncryptionPolicy == null)
    {
          throw new InvalidOperationException(SR.EncryptionPolicyMissingInStrictMode);
    }
}

在https://github.com/Azure/azure-storage-net/blob/master/Lib/Common/Blob/BlobRequestOptions.cs中

因此，基本上可以这样做：

BlobRequestOptions blobOptions = new BlobRequestOptions
{
    MaximumExecutionTime = TimeSpan.FromSeconds(5),
    ParallelOperationThreadCount = 48,
    RequireEncryption = false
};

await lockBlob.UploadTextAsync(data, null, null, blobOptions, null);

我避免在AssertPolicyIfRequired检查中进行检查。因此，将底线设置为RequireEncryption = false或将其设置为true，并定义适当的加密策略。

现在，这使所有Upload **** Async方法都可以工作。

这是帮助我调试问题的调用堆栈：

{"ClassName":"System.NullReferenceException","Message":"Object reference not set to an instance of an object.","Data":null,"InnerException":null,"HelpURL":null,"StackTraceString":"   at Microsoft.WindowsAzure.Storage.Blob.CloudBlockBlob.<>c__DisplayClass1d.b__f(Action continuation) in c:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\ClassLibraryCommon\Blob\CloudBlockBlob.cs:line 620
   at Microsoft.WindowsAzure.Storage.Blob.CloudBlockBlob.BeginUploadFromStreamHelper(Stream source, Nullable`1 length, AccessCondition accessCondition, BlobRequestOptions options, OperationContext operationContext, AsyncCallback callback, Object state) in c:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\ClassLibraryCommon\Blob\CloudBlockBlob.cs:line 665
   at Microsoft.WindowsAzure.Storage.Blob.CloudBlockBlob.BeginUploadFromStream(Stream source, AccessCondition accessCondition, BlobRequestOptions options, OperationContext operationContext, AsyncCallback callback, Object state) in c:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\ClassLibraryCommon\Blob\CloudBlockBlob.cs:line 477
   at Microsoft.WindowsAzure.Storage.Blob.CloudBlockBlob.BeginUploadFromByteArray(Byte[] buffer, Int32 index, Int32 count, AsyncCallback callback, Object state) in c:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\ClassLibraryCommon\Blob\CloudBlockBlob.cs:line 1146
   at Microsoft.WindowsAzure.Storage.Core.Util.AsyncExtensions.TaskFromVoidApm[T1,T2,T3](Func`6 beginMethod, Action`1 endMethod, T1 arg1, T2 arg2, T3 arg3, CancellationToken cancellationToken) in c:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\ClassLibraryCommon\Core\Util\AsyncExtensions.cs:line 210
   at Microsoft.WindowsAzure.Storage.Blob.CloudBlockBlob.UploadFromByteArrayAsync(Byte[] buffer, Int32 index, Int32 count, CancellationToken cancellationToken) in c:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\ClassLibraryCommon\Blob\CloudBlockBlob.cs:line 1204
   at Microsoft.WindowsAzure.Storage.Blob.CloudBlockBlob.UploadFromByteArrayAsync(Byte[] buffer, Int32 index, Int32 count) in c:\Program Files (x86)\Jenkins\workspace\release_dotnet_master\Lib\ClassLibraryCommon\Blob\CloudBlockBlob.cs:line 1190

关于c# - 与Azure存储异步创建Blob时发生异常-UploadTextAsync，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/50477987/