Azure云存储中的Silverlight XAP

Question

I have a Silverlight xap that displays a green rectangle.

This xap is part of an ASP.NET website in the Azure cloud.

To make it easier to upgrade the Xap, I have moved it into Cloud Storage as a blob, and reference it with an https url.

Now the Xap does not start. No error message is displayed. There is white space where the xap should be.

I have searched the Internet for a solution. There are many solutions for when the Xap is accessing a service on another domain, or accessing blob storage on another domain. But this is not the same as my problem. My xap does not access a service. It displays a green rectangle.

How can I fix this?

Answer 1

Thank you Tom and Gaurav for getting me there. Here is my solution:

1) Created a file called "clientaccesspolicy.xml". I used lower-case letters, not sure it matters. In the file put the following:

<?xml version="1.0" encoding="utf-8"?>
<access-policy>
<cross-domain-access>
    <policy>
        <allow-from http-request-headers="SOAPAction">
            <domain uri="*"/>
        </allow-from>
        <grant-to>
            <resource path="/" include-subpaths="true"/>
        </grant-to>
    </policy>
</cross-domain-access>

2) Uploaded this file to the root of your blob container. Using VS2010 to access my blob storage, so cannot see the root ($root). Wrote console app to upload and set the content-type. Again, not sure if setting the content-type is necessary, but could be a gotcha.

This is the class I used:

namespace ConsoleApplication
{

/// <summary>
/// 
/// </summary>
public class BlobStorageContainer
{

    /////////////////////////////////////////////////////////////
    // Constants

    private const string BLOB_CONNECTION = <get this from the windows azure portal>;

    public const string ROOT_CONTAINER_NAME = "$root";


    /////////////////////////////////////////////////////////////
    // Attributes

    private static CloudStorageAccount _storageAccount;

    private static CloudBlobClient _blobClient;

    private CloudBlobContainer _container;


    /////////////////////////////////////////////////////////////
    // Construction

    static BlobStorageContainer()
    {

        // Create storage account
        _storageAccount = CloudStorageAccount.Parse(BLOB_CONNECTION);

        // Construct cloud blob client
        _blobClient = _storageAccount.CreateCloudBlobClient();

    }

    public BlobStorageContainer(string strContainer)
    {

        // Get the audio-files container
        _container = _blobClient.GetContainerReference(strContainer);

        try
        {

            // If container does not exist...
            if (!_container.Exists())
            {

                // Create container
                _container.CreateIfNotExists();

                // Set permissions
                BlobContainerPermissions permissions = new BlobContainerPermissions { PublicAccess = BlobContainerPublicAccessType.Blob };
                _container.SetPermissions(permissions);

            }

        }
        catch (Exception x)
        {

            // Reset reference
            _container = null;

            // throw back
            throw x;

        }
    }


    /////////////////////////////////////////////////////////////
    // Operations

    public void SetContentType(string strName, string strContentType)
    {

        // Retrieve the block-blob
        CloudBlockBlob blob = _container.GetBlockBlobReference(strName);
        if (blob.Exists())
        {

            // If props need changing...
            if (blob.Properties.ContentType != strContentType)
            {

                // Set properties
                blob.Properties.ContentType = strContentType;
                blob.SetProperties();

            }

        }

    }

    public void UploadFile(string strFilepath,string strName)
    {

        // Get blob
        CloudBlockBlob blob = _container.GetBlockBlobReference(strName);

        // Open file
        using(FileStream fs = new FileStream(strFilepath,FileMode.Open,FileAccess.Read))
        {
            blob.UploadFromStream(fs);
        } // using fs

    }

    public void WalkBlobs(Func<string, long, string, bool> fnCallback)
    {

        // Loop through the blobs
        foreach (IListBlobItem loop in _container.ListBlobs())
        {

            // If this is a block blob...
            if (loop is CloudBlockBlob)
            {

                // Get the blob
                CloudBlockBlob blob = loop as CloudBlockBlob;

                // Callback function
                bool bContinue = fnCallback(blob.Name, blob.Properties.Length, blob.Properties.ContentType);
                if (!bContinue)
                    break;

            }

        }

    }


}

}

and then did this in the Main function:

// Open container
BlobStorageContainer container = new BlobStorageContainer(BlobStorageContainer.ROOT_CONTAINER_NAME);

// Upload file
container.UploadFile(@"D:\Workspace\clientaccesspolicy.xml", "clientaccesspolicy.xml");

// Set content type
container.SetContentType("clientaccesspolicy.xml", "text/xml");

3) In my html, changed XAP urls from HTTPS to HTTP. For some reason, this DID NOT WORK:

<param name="source" value="https://<blobaccount>.blob.core.windows.net/container1/MySilverlight.xap"/>

but this did:

<param name="source" value="http://<blobaccount>.blob.core.windows.net/container1/MySilverlight.xap"/>