Question

I know this question can be interpreted as a duplicate, but I can simply not get the blop service working. I have followed the standard example on msdn. I have implemented in my code but followed the example. I can get my MobileService, with the supplied script in the example, to insert a blob with open properties. I then use this code to upload an image to the blob storage:

 BitmapImage bi = new BitmapImage();
 MemoryStream stream = new MemoryStream();
 if (bi != null)
 {
      WriteableBitmap bmp = new WriteableBitmap((BitmapSource)bi);
      bmp.SaveJpeg(stream, bmp.PixelWidth, bmp.PixelHeight, 0, 100);
 }

 if (!string.IsNullOrEmpty(uploadImage.SasQueryString))
 {
       // Get the URI generated that contains the SAS 
       // and extract the storage credentials.
       StorageCredentials cred = new StorageCredentials(uploadImage.SasQueryString);
       var imageUri = new Uri(uploadImage.ImageUri);

       // Instantiate a Blob store container based on the info in the returned item.
       CloudBlobContainer container = new CloudBlobContainer(
       new Uri(string.Format("https://{0}/{1}",
       imageUri.Host, uploadImage.ContainerName)), cred);

       // Upload the new image as a BLOB from the stream.
       CloudBlockBlob blobFromSASCredential = container.GetBlockBlobReference(uploadImage.ResourceName);
       await blobFromSASCredential.UploadFromStreamAsync(stream);//error!

       // When you request an SAS at the container-level instead of the blob-level,
       // you are able to upload multiple streams using the same container credentials.

       stream = null;
 }

I am getting an error in this code at the point marked error, with the following error:

+       ex  {Microsoft.WindowsAzure.Storage.StorageException: The remote server returned an error: NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound. ---> System.Net.WebException: The remote server returned an error: NotFound.

Which I do not understand since the code that returns the string from the script is:

// Generate the upload URL with SAS for the new image.
var sasQueryUrl = blobService.generateSharedAccessSignature(item.containerName, 
item.resourceName, sharedAccessPolicy);

// Set the query string.
item.sasQueryString = qs.stringify(sasQueryUrl.queryString);

// Set the full path on the new new item, 
// which is used for data binding on the client. 
item.imageUri = sasQueryUrl.baseUrl + sasQueryUrl.path;

Of course this also depicts that I do not completely grasp the construction of the blob storage. And therefore any help would be appreciated.

Comment elaborations From the server code it should create a public note for at least 5 minutes. And therefore not be an issue. My server script is the same as the link. But replicated here:

var azure = require('azure');
var qs = require('querystring');
var appSettings = require('mobileservice-config').appSettings;

function insert(item, user, request) {
// Get storage account settings from app settings. 
var accountName = appSettings.STORAGE_ACCOUNT_NAME;
var accountKey = appSettings.STORAGE_ACCOUNT_ACCESS_KEY;
var host = accountName + '.blob.core.windows.net';

if ((typeof item.containerName !== "undefined") && (
item.containerName !== null)) {
    // Set the BLOB store container name on the item, which must be lowercase.
    item.containerName = item.containerName.toLowerCase();

    // If it does not already exist, create the container 
    // with public read access for blobs.        
    var blobService = azure.createBlobService(accountName, accountKey, host);
    blobService.createContainerIfNotExists(item.containerName, {
        publicAccessLevel: 'blob'
    }, function(error) {
        if (!error) {

            // Provide write access to the container for the next 5 mins.        
            var sharedAccessPolicy = {
                AccessPolicy: {
                    Permissions: azure.Constants.BlobConstants.SharedAccessPermissions.WRITE,
                    Expiry: new Date(new Date().getTime() + 5 * 60 * 1000)
                }
            };

            // Generate the upload URL with SAS for the new image.
            var sasQueryUrl = 
            blobService.generateSharedAccessSignature(item.containerName, 
            item.resourceName, sharedAccessPolicy);

            // Set the query string.
            item.sasQueryString = qs.stringify(sasQueryUrl.queryString);

            // Set the full path on the new new item, 
            // which is used for data binding on the client. 
            item.imageUri = sasQueryUrl.baseUrl + sasQueryUrl.path;

        } else {
            console.error(error);
        }

        request.execute();
    });
} else {
    request.execute();
}
}

The idea with the pictures is that other users of the app should be able to access them. As far as I understand I have made it public, but only write public for 5 minutes. The url for the blob I save in a mobileservice table, where the user needs to be authenticated, I would like the same safety on the storage. But do not know if this is accomplished? I am sorry for all the stupid questions, but I have not been able to solve it on my own so I have to "seem" stupid :)

Was it helpful?

Solution

If someone ends up in here needing help. The problem for me was the uri. It should have been http and not https. Then there were no error uploading.

But displaying the image even on a test image control from the toolbox, did not succeed. The problem was I had to set the stream to the begining:

stream.Seek(0, SeekOrigin.Begin);

Then the upload worked and was able to retrieve the data.

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