System.Data.SqlClient.SqlException: Unable to open the requested database for login

The problem is this ... I run the open page directly in VS2008, I can connect to the database ... But by entering the address, you can also open the Web page, but the problem is related to the database ...

Unable to open the requested database "Takeclass" for login. Login failed.

User ' 2d2727e2578f446aspnet ' login failed.

Note: An unhandled exception occurred during the execution of the current WEB request. Check the stack trace for more information about the error and where the error occurred in the code.

Exception Details: System.Data.SqlClient.SqlException: Unable to open the requested database "Takeclass" for the login. Login failed.

User ' 2d2727e2578f446aspnet ' login failed.

have also encountered this problem before, search after the following method is resolved.

1. Open the Database Enterprise Manager, and then select the database---security---find just the error of which ' xxxaspnet '--Right Key "property";

2. Select the user mapping option---to select the database in which we want to access

3. Make sure---then select which database we have just chosen, and select "db_owner" permission in the following "Database role membership"