Cross-origin access using Silverlight and several common solutions

The cross-origin issue is discovered only when errors occur during Silverlight access to JSON data. Therefore, we sorted out some of the content and listed it.

By default, Silverlight imposes strict restrictions on URL access to ensure security. It only allows access to URL resources in the same subdomain.

The following table lists URL access rules in Silverlight 2.0:

	WebClient object	Media, images, ASX	XAML files and font files	Streaming Media
Protocols allowed	HTTP and https	HTTP, https, file	HTTP, https, file	HTTP
Cross-protocol access	Not Allowed	Not Allowed	Not Allowed	Access from HTTPS is not allowed
Cross-web domain access	Not Allowed	If it is not from https, allow	Not Allowed	Allow
Cross-security region access (Windows)	Not Allowed	Not Allowed	Not Allowed	Not Allowed
Cross-security region access (Macintosh)	Not Allowed	Allow	Not Allowed	Allow
Redirect allowed	Same Domain Allowed	Allow	Same Domain Allowed	Not Allowed

If WCF and Silverlight web are not on the same site, we need to put two XML files clientaccesspolicy. xml and crossdomain. XML in the root domain of the accessed end.
If you want to access the resources of another site through webclinet, you need to put the domain access policy XML file on the accessed site. Otherwise, the event parameter report in the complete event contains a null object reference.

The format of the clientaccesspolicy. xml file should not be set to UTF-8; otherwise, errors may occur easily.

<? XML version = "1.0" encoding = "UTF-8"?>
<Access-Policy>
<Cross-domain-access>
<Policy>
<Allow-from>
<Domain uri = "*"/>
</Allow-from>
<Grant-to>
<Resource Path = "/" include-subpaths = "true"/>
</Grant-to>
</Policy>
</Cross-Domain-access>
</Access-Policy>

Crossdomain. xml file format

Crossdomain. the XML format is very simple. Its root node is <cross-domain-Policy>, which contains one or more <allow-access-from> nodes, <allow-access-from> there is an attribute domain with a value of the allowed domain, which can be the exact IP address, an exact domain, or a wildcard domain (any domain ). Below are two examples:

Program code
<? XML version = "1.0"?>
<Cross-domain-Policy>
<Allow-access-from domain = "http://www.lishewen.com.cn/"/>
<Allow-access-from domain = "* .lishewen.com.cn"/>
<Allow-access-from domain = "222.217.221.16"/>
</Cross-Domain-Policy>

Program code
<? XML version = "1.0"?>
<Cross-domain-Policy>
<Allow-access-from domain = "*"/>
</Cross-Domain-Policy>

The second example allows access to any domain. We recommend that you store the crossdomain. xml file in the root directory of the site!

Such as: http://bbs.lishewen.com.cn/crossdomain.xml

Here I also got an example of Silverlight to test

Http://silverlight.lishewen.net.cn/SyndicationFeedReader/

For more information about clientaccesspolicy. xml and crossdomain. XML, see msdn http://msdn.microsoft.com/en-us/library/cc645032 (vs.95). aspx.

Documents from: http://www.cnblogs.com/format/articles/1282203.html

Http://blog.lishewen.com.cn/post/2008/06/e4bdbfe794a8crossdomainxmle8aea9Silverlighte58fafe4bba5e8b7a8e59f9fe4bca0e8be93e695b0e68dae.aspx