LinqDataSourceSelectEventArgs Class


Provides data for the Selecting event.

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


Public Class LinqDataSourceSelectEventArgs
	Inherits CancelEventArgs


Gets values that determine how the data is returned.


Gets or sets a value indicating whether the event should be canceled.(Inherited from CancelEventArgs.)


Gets the collection of parameters that is used to create the GroupBy clause.


Gets the collection of parameters that is used to create the OrderBy clause.


Gets the collection of parameters that are used to create the clause that specifies how grouped data is sorted.


Gets or sets the data object that is used in the data query.


Gets the collection of parameters that is used to create the Select clause.


Gets the collection of parameters that is used to create the Where clause.


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


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


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


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


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


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

The LinqDataSourceSelectEventArgs object is passed to event handlers for the Selecting event of the LinqDataSource control. You use the LinqDataSourceSelectEventArgs object to manually specify what data is returned, and how the data is sorted and paged when it is returned. You can programmatically add or remove parameters to the GroupBy, OrderBy, OrderGroupsBy, Select, and Where clauses by using the GroupByParameters, OrderByParameters, OrderGroupsByParameters, SelectParameters, and WhereParameters collections.

The Result property enables you to change the data object that is used for the query. If you assign an object to the Result property, that object will be used for queries instead of the object specified in the TableName property of the LinqDataSource control.

The Arguments property enables you to customize how returned data is sorted and paged. The data-bound control passes sorting and paging properties through the Arguments property. If you have to manually handle sorting or paging, set the AutoSort property or AutoPage property of the LinqDataSource control to false. You can then perform the customized query for sorting or paging in a handler for the Selecting event.

If the RetrieveTotalRowCount property is set to true, you must return a value for the TotalRowCount property.

The following example shows how to set the Result property to the result of a search made by using language-integrated query (LINQ).

Protected Sub LinqDataSource_Selecting(sender As Object, e As LinqDataSourceSelectEventArgs)
    Dim exampleContext As New ExampleDataContext()

    e.Result = From p In exampleContext.Products Where p.Category = "Beverages"
               Select New With { _
                    Key .ID = p.ProductID, _
                    Key .Name = p.Name _
End Sub

The following example shows how to set the Result property to an array of string values that is defined in the Web page.

Partial Class Default3
    Inherits System.Web.UI.Page

    Dim citiesArray() As String = _
    { _
        "Atlanta", _
        "Charlotte", _
        "Denver", _
        "New York", _
        "San Francisco" _

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

    End Sub

    Protected Sub LinqDataSource_Selecting(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.LinqDataSourceSelectEventArgs) Handles LinqDataSource1.Selecting
        Dim cities = From city In citiesArray _
                     Where city > "B" _
                     Select city
        e.Result = cities
        ' Or we could set e.Result = citiesArray to return all rows.
    End Sub

End Class

.NET Framework
Available since 3.5

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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