我正在尝试实现Learn Path中共享的示例https://github.com/MicrosoftDocs/mslearn-support-concurrency-blob-storage/blob/master/src/OptimisticNewsEditor/Program.cs
我正在尝试使用v12 dll，它是Azure.Storage.Blobs这是我的密码。
public static async Task Main()
{
BlobContainerClient container;
try
{
container = new BlobServiceClient(connectionString).GetBlobContainerClient(containerName);
await container.CreateIfNotExistsAsync(PublicAccessType.None);
}
catch (Exception)
{
var msg = $"Storage account not found. Ensure that the environment variable " +
" is set to a valid Azure Storage connection string and that the storage account exists.";
Console.WriteLine(msg);
return;
}
// First, the newsroom chief writes the story notes to the blob
await SimulateChief();
Console.WriteLine();
await Task.Delay(TimeSpan.FromSeconds(2));
// Next, two reporters begin work on the story at the same time, one starting soon after the other
var reporterA = SimulateReporter("Reporter A", writingTime: TimeSpan.FromSeconds(12));
await Task.Delay(TimeSpan.FromSeconds(4));
var reporterB = SimulateReporter("Reporter B", writingTime: TimeSpan.FromSeconds(4));
await Task.WhenAll(reporterA, reporterB);
await Task.Delay(TimeSpan.FromSeconds(2));
Console.WriteLine();
Console.WriteLine("=============================================");
Console.WriteLine();
Console.WriteLine("Reporters have finished, here's the story saved to the blob:");
BlobDownloadInfo story = await container.GetBlobClient(blobName).DownloadAsync();
Console.WriteLine(new StreamReader(story.Content).ReadToEnd());
}
private static async Task SimulateReporter(string authorName, TimeSpan writingTime)
{
// First, the reporter retrieves the current contents
Console.WriteLine($"{authorName} begins work");
var blob = new BlobContainerClient(connectionString, containerName).GetBlobClient(blobName);
var contents = await blob.DownloadAsync();
Console.WriteLine($"{authorName} loads the file and sees the following content: "{new StreamReader(contents.Value.Content).ReadToEnd()}"");
// Store the current ETag
var properties = await blob.GetPropertiesAsync();
var currentETag = properties.Value.ETag;
Console.WriteLine($""{contents}" has this ETag: {properties.Value.ETag}");
// Next, the author writes their story. This takes some time.
Console.WriteLine($"{authorName} begins writing their story...");
await Task.Delay(writingTime);
Console.WriteLine($"{authorName} has finished writing their story");
try
{
// Finally, they save their story back to the blob.
var story = $"[[{authorName.ToUpperInvariant()}'S STORY]]";
await uploadDatatoBlob(blob, story);
Console.WriteLine($"{authorName} has saved their story to Blob storage. New blob contents: "{story}"");
}
catch (RequestFailedException e)
{
// Catch error if the ETag has changed it's value since opening the file
Console.WriteLine($"{authorName} sorry cannot save the file as server returned an error: {e.Message}");
}
}
private static async Task SimulateChief()
{
var blob = new BlobContainerClient(connectionString, containerName).GetBlobClient(blobName);
var notes = "[[CHIEF'S STORY NOTES]]";
await uploadDatatoBlob(blob, notes);
Console.WriteLine($"The newsroom chief has saved story notes to the blob {containerName}/{blobName}");
}
private static async Task uploadDatatoBlob(BlobClient blob, string notes)
{
byte[] byteArray = Encoding.UTF8.GetBytes(notes);
MemoryStream stream = new MemoryStream(byteArray);
await blob.UploadAsync(stream, overwrite: true);
}
在上传之前，我需要修改UploadAsync来检查ETag。在旧版本的Azure.Net CLI中，我们有Microsoft.Azure.Storage.Blob dll，现在它通过处理乐观并发
await blob.UploadTextAsync(story, null, accessCondition: AccessCondition.GenerateIfMatchCondition(currentETag), null, null);
如何在v12 dll中执行此操作。感谢您的帮助。
请使用以下UploadAsync方法的覆盖：
UploadAsync(Stream, BlobHttpHeaders, IDictionary<String,String>, BlobRequestConditions, IProgress<Int64>, Nullable<AccessTier>, StorageTransferOptions, CancellationToken)
您可以将访问条件定义为BlobRequestConditions参数的一部分。