Problems with using wcf ria in Silverlight empty domain service class

The empty domain service class is displayed during the use of WCF Ria, And the LINQ has been configured. The problem has not been solved for a period of time in the search. Today, a post completely ends this problem. It is also mentally retarded: compilation is required before using WCF to establish domain service class, the created data is displayed.

Set up the required environment and steps:

1. Install silverlight4_tools;

2. riaservicestoolkit;

3. compile the data after you create a data-to-SQL statement;

4. Create a domain service class.