RangeExpression Class (System.Web.UI.WebControls.Expressions)

The QueryExtender control provides the ability to filter data in a Web page by using classes in the System.Web.UI.WebControls.Expressions namespace. These classes include the RangeExpression class.

The RangeExpression class searches a data column using a pair of values that define the range. You use the DataField property to specify the column to search. You use the MinType property to specify whether to include or exclude the minimum in the search results, and you use the MaxType property to specify whether to include or exclude the maximum value. The maximum and minimum values can be specified in ASP.NET controls and the values can then be passed to the QueryExtender control as parameters in ControlParameter controls. The results are typically displayed in a data-bound control.

The following example shows how to search the ListPrice column in the Products table of the AdventureWorks database for products that have a list price in the range that is specified in the FromTextBox and ToTextBox text boxes. The filter includes the minimum value but excludes the maximum value in the results. The results are displayed in a Label control.

This code example is part of a larger example provided in Walkthrough: Filtering Data in a Web Page Using Declarative Syntax.

  <form id="form1" runat="server">

    <asp:TextBox ID="FromTextBox" runat="server"></asp:TextBox>
    <asp:TextBox ID="ToTextBox" runat="server"></asp:TextBox>
    <asp:Button ID="Button1" runat="server" Text="Button" />

    <asp:LinqDataSource ID="LinqDataSource1" 
        ContextTypeName=" FilterDemo.AdventureworksDataContext"  
        runat="server" TableName="Products">
    </asp:LinqDataSource>

    <asp:QueryExtender runat="server"  
        TargetControlID="LinqDataSource1">

    <asp:RangeExpression DataField="ListPrice"  
        MinType="Inclusive" MaxType="Exclusive">
    <asp:ControlParameter ControlID="FromTextBox" />
    <asp:ControlParameter ControlID="ToTextBox" />
    </asp:RangeExpression>
</asp:QueryExtender>

<asp:GridView ID="GridView1" runat="server"    
    DataSourceID="LinqDataSource1" AllowPaging="True" >
</asp:GridView>

</form>

.NET Framework

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

Other Resources