如何下载 Block Blob (Base64) 文件并使用 Azure Blob 存储将其转换为 PNG？

Question

我目前正在开发一个网站，该网站将从 Azure Blob 存储下载 Blob 文件并显示为图像。该文件已保存为 Base64，我在将文件下载到流时遇到问题。我尝试了多种方法，一切都没有结果。这是我目前所拥有的：

[HttpGet]
    public async IActionResult ViewFile(string name)
    {

        BlobServiceClient blobServiceClient = new BlobServiceClient(System.Environment.GetEnvironmentVariable("BlobConnection"));

        BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient("store-images");

        // this will allow us access to the file inside the container via the file name
        //var blob = containerClient.GetBlobs(prefix: name);

        //var blobContainerUri = containerClient.GetBlobClient(name);

        BlobClient blob = containerClient.GetBlobClient(name);

        MemoryStream stream = new MemoryStream();

        await blob.DownloadStreamingAsync(stream);

        stream.Position = 0;

        return stream;
    }

Answer 1

这是对我有用的逻辑

string storageAccount_connectionString = "**Enter Connection String**";

CloudStorageAccount mycloudStorageAccount = CloudStorageAccount.Parse(storageAccount_connectionString);
CloudBlobClient blobClient = mycloudStorageAccount.CreateCloudBlobClient();

CloudBlobContainer container = blobClient.GetContainerReference(azure_ContainerName);
CloudBlockBlob cloudBlockBlob = container.GetBlockBlobReference(filetoDownload);           

// provide the file download location below            
Stream file = File.OpenWrite(@"C:\location" + filetoDownload);

cloudBlockBlob.DownloadToStream(file);
file.Close();

//Converting Base64 to png
string base64String = File.ReadAllText(@"C:\location\base64.txt");
byte[] imgBytes = Convert.FromBase64String(base64String);

using (var imageFile = new FileStream(@"C:\location\sample.png", FileMode.Create))
{
       imageFile.Write(imgBytes, 0, imgBytes.Length);
       imageFile.Flush();
}

参考：Blog to convert base64 to png

Download blob from storage