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RangeExpression Class

Provides a way to determine whether a value is greater than or less than a specified value, or whether a value is between two specified values.

Namespace:  System.Web.UI.WebControls.Expressions
Assembly:  System.Web.Extensions (in System.Web.Extensions.dll)

public class RangeExpression : ParameterDataSourceExpression

The RangeExpression type exposes the following members.

  NameDescription
Public methodRangeExpressionInitializes a new instance of the RangeExpression class.
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  NameDescription
Protected propertyContextGets the HttpContext instance of the owner control. (Inherited from DataSourceExpression.)
Public propertyDataFieldGets or sets the field to use for the comparison.
Public propertyDataSourceGets the data source object that is associated with the owner control. (Inherited from DataSourceExpression.)
Protected propertyIsTrackingViewStateGets a value that indicates whether a data source expression object is tracking its view state changes. (Inherited from DataSourceExpression.)
Public propertyMaxTypeGets or sets the maximum value of the range.
Public propertyMinTypeGets or sets the minimum value of the range.
Protected propertyOwnerGets the owner control. (Inherited from DataSourceExpression.)
Public propertyParametersGets the parameters that are associated with this DataSourceExpression object. (Inherited from ParameterDataSourceExpression.)
Protected propertyViewStateGets an instance of the StateBag class that contains the current view state information. (Inherited from DataSourceExpression.)
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  NameDescription
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as the default hash function. (Inherited from Object.)
Public methodGetQueryableGets the IQueryable object that the range comparison was performed on. (Overrides DataSourceExpression.GetQueryable(IQueryable).)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodLoadViewStateLoads the state of the values in the ParameterDataSourceExpression object that must be persisted. (Inherited from ParameterDataSourceExpression.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Protected methodSaveViewStateSaves the current view state of the ParameterDataSourceExpression object. (Inherited from ParameterDataSourceExpression.)
Public methodSetContextExecutes the expression by using the specified owner control, context, and data source. (Inherited from ParameterDataSourceExpression.)
Public methodSetDirtyMarks the DataSourceExpression object so that its state will be saved in view state. (Inherited from DataSourceExpression.)
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Protected methodTrackViewStateTracks view-state changes of the ParameterDataSourceExpression object so that the changes can be stored in the StateBag object for the object. (Inherited from ParameterDataSourceExpression.)
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  NameDescription
Explicit interface implemetationPrivate propertyIStateManager.IsTrackingViewStateWhen implemented by a class, gets a value that indicates whether a data source expression object is tracking its view state changes. (Inherited from DataSourceExpression.)
Explicit interface implemetationPrivate methodIStateManager.LoadViewStateWhen implemented by a class, loads the previously saved view state of the data source expression object. (Inherited from DataSourceExpression.)
Explicit interface implemetationPrivate methodIStateManager.SaveViewStateWhen implemented by a class, saves the current view state of the DataSourceExpression object. (Inherited from DataSourceExpression.)
Explicit interface implemetationPrivate methodIStateManager.TrackViewStateWhen implemented by a class, tracks view state changes of the DataSourceExpression object so that the changes can be stored in the StateBag object for the data source expression object. (Inherited from DataSourceExpression.)
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ExceptionCondition
InvalidOperationException

The DataField property is null.

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

Supported in: 4.5.2, 4.5.1, 4.5, 4

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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