问题描述
下载Blob时我需要一个进度指示器。
上传时进度指示器已经可以工作。我在 BlobUploadOptions 中使用Progresshandler。
BlobDownloadDetails 似乎有进度状态。但是,我不知道如何将其集成以使其正常工作。
这是我的代码:
IKeyEncryptionKey key;
IKeyEncryptionKeyResolver keyResolver;
// Create the encryption options to be used for upload and download.
ClientSideEncryptionoptions encryptionoptions = new ClientSideEncryptionoptions(ClientSideEncryptionVersion.V1_0)
{
KeyEncryptionKey = key,KeyResolver = keyResolver,// string the storage client will use when calling IKeyEncryptionKey.WrapKey()
KeyWrapAlgorithm = "some algorithm name"
};
// Set the encryption options on the client options
BlobClientOptions options = new SpecializedBlobClientOptions() { ClientSideEncryption = encryptionoptions };
// Get your blob client with client-side encryption enabled.
// Client-side encryption options are passed from service to container clients,and container to blob clients.
// Attempting to construct a BlockBlobClient,PageBlobClient,or AppendBlobClient from a BlobContainerClient
// with client-side encryption options present will throw,as this functionality is only supported with BlobClient.
BlobClient blob = new BlobServiceClient(connectionString,options).GetBlobContainerClient("myContainer").GetBlobClient("myBlob");
BlobUploadOptions uploadOptions = new BlobUploadOptions();
uploadOptions.ProgressHandler = new Progress<long>(percent =>
{
progressbar.Maximum = 100;
progressbar.Value = Convert.ToInt32(percent * 100 / file.Length);
});
// Upload the encrypted contents to the blob.
blob.UploadAsync(content: stream,options: uploadOptions,cancellationToken: CancellationToken.None);
// Download and decrypt the encrypted contents from the blob.
MemoryStream outputStream = new MemoryStream();
blob.DownloadTo(outputStream);
解决方法
当前,DownloadTo
方法不支持进度监视器。浏览源代码时,DownloadTo
类中定义了BlobBaseClient
方法,而继承自UploadAsync
类的BlobClient
类中定义了BlobBaseClient
方法。因此,我认为他们可能会在基类BlobBaseClient
中错过此功能。
但是有一种解决方法,代码如下:
class Program
{
static void Main(string[] args)
{
var connectionString = "DefaultEndpointsProtocol=https;AccountName=xx;AccountKey=xxx;EndpointSuffix=core.windows.net";
BlobServiceClient blobServiceClient = new BlobServiceClient(connectionString);
BlobContainerClient blobContainerClient = blobServiceClient.GetBlobContainerClient("xxx");
BlobClient blobClient = blobContainerClient.GetBlobClient("xxx");
var blobToDownload = blobClient.Download().Value;
MemoryStream outputStream = new MemoryStream();
var downloadBuffer = new byte[81920];
int bytesRead;
int totalBytesDownloaded = 0;
while ((bytesRead = blobToDownload.Content.Read(downloadBuffer,downloadBuffer.Length)) != 0)
{
outputStream.Write(downloadBuffer,bytesRead);
totalBytesDownloaded += bytesRead;
Console.WriteLine(GetProgressPercentage(blobToDownload.ContentLength,totalBytesDownloaded));
}
Console.WriteLine("**completed**");
Console.ReadLine();
}
private static double GetProgressPercentage(double totalSize,double currentSize)
{
return (currentSize / totalSize) * 100;
}
}
这里是reference doc。