OrderByExpression Class

OrderByExpression Class

.NET Framework (current version)
 

Provides a way to apply a sort expression to an IQueryable object.

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

System.Object
  System.Web.UI.WebControls.Expressions.DataSourceExpression
    System.Web.UI.WebControls.Expressions.OrderByExpression

public class OrderByExpression : DataSourceExpression

NameDescription
System_CAPS_pubmethodOrderByExpression()

Initializes a new instance of the OrderByExpression class.

NameDescription
System_CAPS_protpropertyContext

Gets the HttpContext instance of the owner control.(Inherited from DataSourceExpression.)

System_CAPS_pubpropertyDataField

Gets or sets the property of the IQueryable object to sort by.

System_CAPS_pubpropertyDataSource

Gets the data source object that is associated with the owner control.(Inherited from DataSourceExpression.)

System_CAPS_pubpropertyDirection

Gets and sets the sort direction of the IQueryable data source object.

System_CAPS_protpropertyIsTrackingViewState

Gets a value that indicates whether a data source expression object is tracking its view state changes.(Inherited from DataSourceExpression.)

System_CAPS_protpropertyOwner

Gets the owner control.(Inherited from DataSourceExpression.)

System_CAPS_pubpropertyThenByExpressions

Gets or sets the collection of ThenBy expressions to apply after an OrderByExpression value is applied to the data source.

System_CAPS_protpropertyViewState

Gets an instance of the StateBag class that contains the current view state information.(Inherited from DataSourceExpression.)

NameDescription
System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetQueryable(IQueryable)

Applies a sort expression to an IQueryable object based on a DataField value and a Direction value.(Overrides DataSourceExpression.GetQueryable(IQueryable).)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_protmethodLoadViewState(Object)

Loads the state of the values in the DataSourceExpression object that must be persisted.(Inherited from DataSourceExpression.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_protmethodSaveViewState()

Saves the current view state of the DataSourceExpression object.(Inherited from DataSourceExpression.)

System_CAPS_pubmethodSetContext(Control, HttpContext, IQueryableDataSource)

Sets the HTTP context of the DataSourceExpression object that uses the specified owner control, HttpContext instance, and IQueryableDataSource object.(Inherited from DataSourceExpression.)

System_CAPS_pubmethodSetDirty()

Marks the DataSourceExpression object so that its state will be saved in view state.(Inherited from DataSourceExpression.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

System_CAPS_protmethodTrackViewState()

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.)

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethodIStateManager.LoadViewState(Object)

When implemented by a class, loads the previously saved view state of the data source expression object.(Inherited from DataSourceExpression.)

System_CAPS_pubinterfaceSystem_CAPS_privmethodIStateManager.SaveViewState()

When implemented by a class, saves the current view state of the DataSourceExpression object.(Inherited from DataSourceExpression.)

System_CAPS_pubinterfaceSystem_CAPS_privmethodIStateManager.TrackViewState()

When 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.)

System_CAPS_pubinterfaceSystem_CAPS_privpropertyIStateManager.IsTrackingViewState

When implemented by a class, gets a value that indicates whether a data source expression object is tracking its view state changes.(Inherited from DataSourceExpression.)

Exception Condition
InvalidOperationException

The DataField property is null.

The OrderByExpression class is used in the QueryExtender control to sort data in ascending or descending order. The sorting is performed by the default comparer for the type of the element.

The QueryExtender control supports a variety of options that you can use to filter data. After you use the filter options, you can use the OrderByExpression object to sort the data.

You specify the data field to sort by using the DataField property. You specify the sort direction by using the Direction property. After the OrderByExpression object has been applied to the data source, you can use the ThenBy expressions to perform a subsequent sort on another data field.

The following example shows how to search the Products table of the AdventureWorks database for products that have names that start with the string that is specified in the SearchTextBox text box. The OrderByExpression object sorts the data by the ListPrice data field in descending order and then by the product ID field in ascending order. The result of the query that is returned from the LinqDataSource control is displayed in a GridView control.

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

.NET Framework
Available since 4.0

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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