Silverlight & Cross-Domain Policy

If you are creating a Silverlight application that makes calls to a web service – either WCF or standard ASP.NET based then you will more than likely need an xml ‘policy’ file that allows cross domain access.

In my case I was calling one of the SharePoint inbuilt web services – lists.asmx from my silverlight application. When I tried to debug the application I received the following error –

An error occurred while trying to make a request to URI ‘http://localhost/sites/mysite/_vti_bin/lists.asmx’. This could be due to attempting to access a service in a cross-domain way without a proper cross-domain policy in place.

To fix this problem you need to create an xml file called ‘clientaccesspolicy.xml’ with the following content –

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

This xml file should be placed in the IIS virtual directory where your web service is located. In my case the SharePoint site collection that contained the web service was inside the IIS default website so I put the xml file in ‘C:\Inetpub\wwwroot’.

Once you have created this xml file make sure you do an IISRESET. Your silverlight application should now be calling the web service correctly and not throwing the above exception.

Hope this helps 🙂

Getting started with the Bing Maps Silverlight SDK

I got the chance this morning to have a look at the newly released Bing Maps Silverlight SDK. The bing maps SDK allows you to add a map to your silverlight application and enhance it by adding pushpins, images, videos, shapes and scalable elements etc.

I’m impressed at how easy it is to get a bing map displaying in your silverlight application and start customising it.

I decided to create this getting started guide to help you create a simple silverlight application displaying a bing map.

When you have completed the guide below you should have a map similar to the one below.

1. Download and install the Bing Maps Silverlight Control SDK from here –

http://www.microsoft.com/downloads/details.aspx?displaylang=en&FamilyID=beb29d27-6f0c-494f-b028-1e0e3187e830

2. Create a new ‘Silverlight Application’ project in Visual Studio 2008/2010 whichever you prefer. When the box pops up to asking whether or not you want VS to host the silverlight app in a new web site – make sure its ticked.

3. Add a reference to the dll’s

Microsoft.Maps.MapControl.dll

Microsoft.Maps.MapControl.Common.dll

you can find these dll’s in a subfolder of the installation directory called ‘Libraries’.

4. Create an account at the ‘Bing Maps Account Center’ and create a new application key (you will need this key to be able to use the bing map control) –

https://www.bingmapsportal.com/

4. Open the MainPage.xaml file of your project (not the web project) and a new xml namespace:

xmlns:m=”clr-namespace:Microsoft.Maps.MapControl;assembly=Microsoft.Maps.MapControl”

5. Next add the following code inside the Grid control (make sure you paste your bing maps application key into the CredentialsProvider property –

<m:Map
Height=”300″
Width=”350″
x:Name=”testMap”
CredentialsProvider=”Your application key goes here”
Background=”White”
Mode=”Road”
Center=”19.642588,50.273438″
ZoomLevel=”0″>
<m:Pushpin Location=”52.97421339369046,-1.246250867843628″/>
<m:Pushpin Location=”-27.469442,153.030136″/>
</m:Map>

6. Refresh the designer in visual studio by clicking the link and then build your project.

7. Hey Presto! – you should now be seeing a bing map just like the one above showing the locations of the ID offices.