Filtering an ASP.NET ObjectDataSource?

Question

I have a ObjectDataSource in a standard ASP.NET WebForm which allows effective paging by only loading the data required for the page the user is viewing. I now want to filter the results on specific columns (say column Customer), how would you go about this?

<asp:ObjectDataSource ID="ticketsDataSource" runat="server"
        SelectMethod="GetTicketsData" EnablePaging="true"
        MaximumRowsParameterName="pageSize"
        StartRowIndexParameterName="startRowIndex"
        TypeName="SupportSystem.App_Code.TicketsDataSource" SelectCountMethod="TotalRowCount">
        <SelectParameters>
            <asp:Parameter Name="startRowIndex" Type="Int32" />
            <asp:Parameter Name="pageSize" Type="Int32" />
        </SelectParameters>
</asp:ObjectDataSource>

I was previously doing everything in code behind as follows, but this meant once numerous tickets were added, the grid was very slow when paging etc as it was loading all the data before rendering etc.

DataSet ds = new DataSet();
Dictionary<string, object> d = new Dictionary<string, object>();
d.Add("@params", "");
ds.ReadXml(new System.IO.StringReader(Database.DAL_XML("Usp_Fetch_Tickets", d).OuterXml));
if (Database_error(ds))
{
   return;
}
var dv = ds.Tables[0].DefaultView;
dv.RowFilter = "Customer LIKE '%abc%'";
var newDS = new DataSet();
var newDT = dv.ToTable();
newDS.Tables.Add(newDT);
gvTickets.DataSource = newDS;
gvTickets.DataBind();

Any ideas of how to effectively filter the ObjectDataSource?

Answer 1

Hi You can use FilterExpression for that purpose. Following is the sample snippet how to achieve that.

<asp:objectdatasource
          id="ObjectDataSource1"
          runat="server"
          selectmethod="GetAllEmployeesAsDataSet"
          typename="Samples.AspNet.CS.EmployeeLogic"
          filterexpression="FullName='{0}'" OnFiltering="ObjectDataSource1_Filtering">
            <filterparameters>
              <asp:formparameter name="FullName" formfield="Textbox1" defaultvalue="Nancy Davolio" />
            </filterparameters>
        </asp:objectdatasource>

Additional info can be found on the following msdn page check this link

Answer 2

You can use the FilterParameters property from markup and then specify one of the Parameter sub classes. For example, suppose you have a TextBox that you provide the user to input a customer name to filter the results by that customer, you will need to use a ControlParameter for this...

<asp:ObjectDataSource>
      <FilterParameters>
          <asp:ControlParameter ControlID="txtCustomer" PropertyName="Text" Name="customerName" />
      </FilterParameters>
</asp:ObjectDataSource>

here txtCustomer would be the ID of the TextBox , Text is the property of that control to get the input value from and customerName is a parameter in the GetTicketsData method that you need to expose in order to pass in the filter value