使用ASP MVC下载并显示私有Azure Blob

Question

我正在使用ASP MVC 5 Razor和Microsoft Azure Blob存储.我可以使用MVC成功地将文档和图像上传到Blob存储,但我很难找到一些MVC示例如何下载和显示文件.

如果将blob存储为公共文件,那么执行此操作将非常简单,但我需要它们是私有的.

任何人都可以给我任何实例或指导如何实现这一目标？

我在下面有一些代码似乎可以检索Blob,但我不知道如何在MVC中使用它来实际在浏览器中显示它.

var fullFileName = "file1.pdf";
var containerName = "default";

// Retrieve storage account from connection string.
CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConfigurationManager.ConnectionStrings["AttachmentStorageConnection"].ConnectionString);

// Create the blob client.
CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

// Retrieve reference to a previously created container.
CloudBlobContainer container = blobClient.GetContainerReference(containerName);

// Retrieve reference to a blob ie "picture.jpg".
CloudBlockBlob blockBlob = container.GetBlockBlobReference(fullFileName);

Answer 1

我根据你的评论作出假设

如果将blob存储为公共文件,那么执行此操作将非常简单,但我需要它们是私有的

因为blob是私有的,所以你试图通过mvc控制器将一个字节数组返回给客户端.

但是,另一种方法是使用SharedAccessSignature为客户端提供对blob的临时访问,然后您可以将其作为公共URL访问.可以在控制器中指定URL有效的时间段.由于客户端将直接从存储中下载文件,因此这也具有从控制器带走负载的优势.

// view model
public class MyViewModel
{
    string FileUrl {get; set;}
}


// controller
public ActionResult MyControllerAction
{
    var readPolicy = new SharedAccessBlobPolicy()
    {
        Permissions = SharedAccessBlobPermissions.Read,
        SharedAccessExpiryTime = DateTime.UtcNow + TimeSpan.FromMinutes(5)
    };
    // Your code ------
    // Retrieve storage account from connection string.
    CloudStorageAccount storageAccount = CloudStorageAccount.Parse(ConfigurationManager.ConnectionStrings   ["AttachmentStorageConnection"].ConnectionString);

    // Create the blob client.
    CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

    // Retrieve reference to a previously created container.
    CloudBlobContainer container = blobClient.GetContainerReference(containerName);

    // Retrieve reference to a blob ie "picture.jpg".
    CloudBlockBlob blockBlob = container.GetBlockBlobReference(fullFileName);
    //------

    var newUri = new Uri(blockBlob.Uri.AbsoluteUri + blockBlob.GetSharedAccessSignature(readPolicy));

    var viewModel = new MyViewModel()
    {
        FileUrl = newUri.ToString()
    };

    return View("MyViewName", viewModel);
}

然后在您的视图中,您可以使用视图模型值

//image
<img src="@Model.FileUrl" />
//in a new tab
<a href="@Model.FileUrl" target="_blank">`Open in new window`</a>