ASP.NET MVC 5, return image from BLOB

Question

Since the domain of the BLOB is inaccessible to some devices, I have to use my Portal(ASP.NET MVC 5) to route the request. Here is the code:

public class ImageController : Controller
{
    [HttpGet]
    public async Task<HttpResponseMessage> GetImage()
    {
        UriBuilder uriBuilder = new UriBuilder()
        {
            Scheme = "https",
            Host = "portalvhdszhm9fnx146yln.blob.core.windows.net",
            Path = "ads/logo.jpg"
        };

        using (HttpClient client = new HttpClient())
        {
            return await client.GetAsync(uriBuilder.ToString());
        }
    }
}

My intent were to make the controller a router to a blob file. But the controller returns the following:

HTTP/1.1 200 OK
Cache-Control: private
Content-Type: text/html; charset=utf-8
Server: Microsoft-IIS/10.0
X-AspNetMvc-Version: 5.2
X-AspNet-Version: 4.0.30319
X-SourceFiles: =?UTF-8?B?RTpcTXlQcm9qXEF1dGhDbG91ZFxBdXRoQ2xvdWRQb3J0YWxcaW1hZ2VcZ2V0aW1hZ2U=?=
X-Powered-By: ASP.NET
Date: Tue, 22 Sep 2015 17:21:02 GMT
Content-Length: 539

StatusCode: 200, ReasonPhrase: 'OK', Version: 1.1, Content: System.Net.Http.StreamContent, Headers:
{
  x-ms-request-id: 3fad2a06-0001-004b-7f5b-f549ad000000
  x-ms-version: 2009-09-19
  x-ms-lease-status: unlocked
  x-ms-blob-type: BlockBlob
  Date: Tue, 22 Sep 2015 17:21:01 GMT
  ETag: 0x8D2BB762EED052B
  Server: Windows-Azure-Blob/1.0
  Server: Microsoft-HTTPAPI/2.0
  Content-Length: 27780
  Content-MD5: pddt6QJK1FjJgiMTp5HKGQ==
  Content-Type: application/octet-stream
  Last-Modified: Sat, 12 Sep 2015 13:29:28 GMT
}

What I want is to show the blob image when the controller is required. What is the correct code to do it?

Could you please provide some sample code of returning FileResult? — Jim Jin, Sep 23 '15 at 03:25

score 2 · Answer 1 · answered Apr 07 '17 at 13:20

If I understand you correctly, you want to return the image to the client, in that case return the content of the response like so:

[HttpGet]
public async Task<FileStreamResult> GetImage()
{
    var cd = new ContentDisposition
    {
        FileName = "My awesome image.jpg",
        Inline = false  //force download instead of viewing in browser
    };

    Response.AppendHeader("Content-Disposition", cd.ToString());

    UriBuilder uriBuilder = new UriBuilder()
    {
        Scheme = "https",
        Host = "portalvhdszhm9fnx146yln.blob.core.windows.net",
        Path = "ads/logo.jpg"
    };

    using (HttpClient client = new HttpClient())
    {
        var resp = await client.GetAsync(uriBuilder.ToString());
        var content = resp.Content as StreamContent;
        var stream = await content.ReadAsStreamAsync();
        return new FileStreamResult(stream, "image/jpeg");
    }            
}

score 0 · Answer 2 · edited May 23 '17 at 12:10

You can try:

public class ImageController : Controller
{
    // GET: Image
    public ActionResult Index(string containerName, string blobName)
    {
       CloudBlobContainer cont = StorageProxy.GetBlobContainer(containerName);
       CloudBlockBlob blob = cont.GetBlockBlobReference(blobName);
       MemoryStream ms = new MemoryStream();

       blob.DownloadToStream(ms);
       ms.Position = 0;

       return new FileStreamResult(ms, "image/png");
    }
}

This should work with the JS from: Using Javascript to Display Blob

ASP.NET MVC 5, return image from BLOB

2 Answers2