Uploading Base64 Image to Azure Blob
<p>I have the following ASPX markup:</p>

<pre><code>&lt;asp:Image ImageUrl="placeholder.png" runat="server" ID="plhdr" /&gt;
</code></pre>

<p>The webpage lets a user upload an image, which is processed through a JavaScript library and then set as the source of the above control. The JavaScript sets the source as a Base64 String like this: </p>

<blockquote>
  <p>data:image/jpeg;base64,/9j/4AAQ...</p>
</blockquote>

<p>I have a function on the same page that is meant to upload the displayed image to Azure Storage and then add a reference to it in Azure SQL. The code I have in the code behind is:</p>

<pre><code>    StorageCredentials creden = new StorageCredentials(accountname, accesskey);
    CloudStorageAccount acc = new CloudStorageAccount(creden, useHttps: true);
    CloudBlobClient client = acc.CreateCloudBlobClient();
    CloudBlobContainer cont = client.GetContainerReference("testcont");
    cont.CreateIfNotExists();
    cont.SetPermissions(new BlobContainerPermissions
    {
        PublicAccess = BlobContainerPublicAccessType.Blob
    });
    CloudBlockBlob cblob = cont.GetBlockBlobReference("cblob");

    var imagesrc = plhdr.ImageUrl;

    cblob.UploadFromFile(@imagesrc);

    var imageUrl = cblob.Uri;
</code></pre>

<blockquote>
  <p>Server Error in '/' Application. Could not find a part of the path
  'D:\Windows\system32\placeholder.png'. Exception Details:
  System.IO.DirectoryNotFoundException: Could not find a part of the
  path 'D:\Windows\system32\dist\img\fling\space.gif'.</p>
</blockquote>

<p>At this line: <code>cblob.UploadFromFile(@imagesrc);</code>.</p>

<p>Hoping someone can point me in the right direction.</p>