ASP.Net DomainDataSource with Select Parameters

12 באפריל 2009

ASP.Net DomainDataSource with Select Parameters

ASP.Net DomainDataSource with Select Parameters

Continuing with .Net RIA Services with Silverlight and ASP.Net. In the last port I wrote about Using DomainDataSource in ASP.Net, and showed its basic usage. In this post I’ll show a more advanced scenario in which you want to use a domain service select method that takes parameters, and get the parameter value from a control on the form.

In the previous post, we had a GridView bound to a DomainDataSource that called a Select Method on the DomainService.

<asp:GridView runat="server" ID="GridView"

  AutoGenerateColumns="true"

  DataSourceID="customersDataSource">

</asp:GridView>

 

<asp:DomainDataSource runat="server" ID="customersDataSource"

  DomainServiceTypeName="Samples.Bank.Domain.BankDomainService"

  SelectMethod="GetCustomers">

</asp:DomainDataSource>

The output was:

ASP.Net DomainDataSource with Select Parameters

Now we want to filter the output list by the City property. To do that, we first have to add a method in our Domain Service that returns the data filtered by a city parameter.

public class BankDomainService : LinqToSqlDomainService<BankDataContext>

{

  public IQueryable<Customer> GetCustomers()

  {

    return this.Context.Customers;

  }

 

  public IQueryable<Customer> GetCustomersByCity(string city)

  {

    if (city == null)

      return GetCustomers();

 

    return GetCustomers().Where(c => c.City == city);

  }

 

  …

}

Notice that GetCustomersByCity method uses the GetCustomers method that returns an IQueryable<Customer> and filters the result by city.

To select which city we want to filter by, lets add a ListBox with some items:

<asp:ListBox ID="lstCities" AutoPostBack="true" runat="server">

  <asp:ListItem>Tel Aviv</asp:ListItem>

  <asp:ListItem>Raanana</asp:ListItem>

  <asp:ListItem>Ramat Gan</asp:ListItem>

</asp:ListBox>

Note that I had to specify AutoPostBack=”true” in make any change to the filter, since this is a server control.

Now, in order to filter the data source according to the domain method with the select parameter I have to specify a SelectParameter that takes its value from the ListBox, and change the select method to execute.

<asp:DomainDataSource runat="server" ID="customersDataSource"
  DomainServiceTypeName="Samples.Bank.Domain.BankDomainService"

  SelectMethod="GetCustomersByCity">

  <SelectParameters>

    <asp:ControlParameter Name="city" ControlID="lstCities"
         PropertyName="SelectedValue"  Type="String" />

  </SelectParameters>

</asp:DomainDataSource>

Now, If we run the application, we can select items in the ListBox, and the items in the GridView will be filtered by the city value.

ASP.Net DomainDataSource with Select Parameters

Enjoy!

Add comment
facebook linkedin twitter email

one comment

  1. insereincLiax9 ביוני 2009 ב 13:05

    Need more info about Visionary manga ? You are welcome here http://anime.goodnanoav.com .

Comments are closed.