To read this code tutorial in its entirety, please visit ASPFree.com: Silverlight 4.0: Query Parameters of DomainDataSource - A Second Glance

The content in the second row of the form is filled with the “DataGrid” as shown below:

        <sdk:DataGrid Grid.Row="1"
            x:Name="dgEmp"
            Margin="8" MinHeight="200" IsReadOnly="True"
            AutoGenerateColumns="True"
            ItemsSource="{Binding Data, ElementName=EmpDomDataSource}" />

The above “DataGrid” fills the entire space in the second row until it reaches the maximum width/height of the form. Furthermore, it is bound to “EmpDomDataSource,” which is defined as follows:

    <UserControl.Resources>
        <riaControls:DomainDataSource x:Name="EmpDomDataSource"
                                      LoadSize="15"
                                      QueryName="GetEmpsByDeptno"
                                      AutoLoad="True">
            <riaControls:DomainDataSource.DomainContext>
                <local:EmpMgrDomainSvc></local:EmpMgrDomainSvc>
            </riaControls:DomainDataSource.DomainContext>
            <riaControls:DomainDataSource.QueryParameters>
                <riaControls:Parameter ParameterName="deptno" Value="{Binding ElementName=txtDeptno, Path=Text}"/>
            </riaControls:DomainDataSource.QueryParameters>
        </riaControls:DomainDataSource>
    </UserControl.Resources>

The above markup explains the following:

• We define a DomainDataSource element named “EmpDomDataSource”
• It is bound to “EmpMgrDomainSvc” (nothing but context).
• It pulls data using “GetEmpsByDeptno” (an entity query of the domain service context).
• The query “GetEmpsByDeptno” accepts a parameter named "deptno."
• The parameter value is directly taken from an existing control, "txtDeptno."