RoleProvider.GetRolesForUser Method (String)


Gets a list of the roles that a specified user is in for the configured applicationName.

Namespace:   System.Web.Security
Assembly:  System.Web.ApplicationServices (in System.Web.ApplicationServices.dll)

Public MustOverride Function GetRolesForUser (
	username As String
) As String()


Type: System.String

The user to return a list of roles for.

Return Value

Type: System.String()

A string array containing the names of all the roles that the specified user is in for the configured applicationName.

GetRolesForUser is called by the GetRolesForUser method of the Roles class to retrieve the role names that the specified user is associated with from the data source. Only the roles for the configured ApplicationName are retrieved.

If no roles exist for the specified user for the configured applicationName, we recommend that your provider return a string array with no elements.

If the specified user name is null or is an empty string, we recommend that your provider throw an exception.

The following code example shows a sample implementation of the GetRolesForUser method.

Public Overrides Function GetRolesForUser(ByVal username As String) As String()
    If username Is Nothing OrElse username = "" Then _
      Throw New ProviderException("User name cannot be empty or null.")

    Dim tmpRoleNames As String = ""

    Dim conn As OdbcConnection = New OdbcConnection(connectionString)
    Dim cmd As OdbcCommand = New OdbcCommand("SELECT Rolename FROM UsersInRoles " & _
                                             " WHERE Username = ? AND ApplicationName = ?", conn)

    cmd.Parameters.Add("@Username", OdbcType.VarChar, 255).Value = username
    cmd.Parameters.Add("@ApplicationName", OdbcType.VarChar, 255).Value = ApplicationName

    Dim reader As OdbcDataReader = Nothing


        reader = cmd.ExecuteReader()

        Do While reader.Read()
            tmpRoleNames &= reader.GetString(0) & ","
    Catch e As OdbcException
        ' Handle exception.
        If Not reader Is Nothing Then reader.Close()
    End Try

    If tmpRoleNames.Length > 0 Then
        ' Remove trailing comma.
        tmpRoleNames = tmpRoleNames.Substring(0, tmpRoleNames.Length - 1)
        Return tmpRoleNames.Split(CChar(","))
    End If

    Return New String() {}
End Function

.NET Framework
Available since 2.0
Return to top