ODataInstantFeedbackSource Class

The data source for the GridControl and SearchLookUpEdit controls that binds these controls to OData service in Instant Feedback Mode.

Namespace: DevExpress.Data.ODataLinq

Assembly: DevExpress.Data.v24.2.dll

Declaration

C#

[ToolboxBitmap(typeof(ResFinder), "Bitmaps256.ODataInstantFeedbackSource.bmp")]
public class ODataInstantFeedbackSource :
    Component,
    IListSource,
    IDXCloneable,
    IOdata

VB.NET

<ToolboxBitmap(GetType(ResFinder), "Bitmaps256.ODataInstantFeedbackSource.bmp")>
Public Class ODataInstantFeedbackSource
    Inherits Component
    Implements IListSource,
               IDXCloneable,
               IOdata

Remarks

The ODataInstantFeedbackSource is a read-only data source for the Instant Feedback Mode.

Instant Feedback Mode

Instant Feedback binding mode is an improvement over regular server mode.

In server mode, the Grid Control loads data in small portions and delegates all data operations (sorting, grouping, filtering and calculating summaries) to the data server. This is the key to the server mode’s high efficiency when working with large volumes of data. The only drawback to using server mode involves data operations when the connection to the server is slow. In this instance, the bound control freezes until the data server completes operations and retrieves results.

With Instant Feedback binding mode, data operations are performed asynchronously in a background thread, and both the bound control and the application remain highly responsive. Currently, this mode is supported by the GridControl and SearchLookUpEdit controls.

For additional information on Instant Feedback mode, refer to the following help topic: Large Data Sources: Server and Instant Feedback Modes.

Sample Code

C#

public partial class Form1 : Form {
    private void Form1_Load(object sender, EventArgs e) {
        oDataInstantFeedbackSource1.KeyExpression =  "CustomerID";
        oDataInstantFeedbackSource1.GetSource += oDataInstantFeedbackSource1_GetSource;
        gridControl1.DataSource = oDataInstantFeedbackSource1;
    }
    void oDataInstantFeedbackSource1_GetSource(object sender, GetSourceEventArgs e) {
        // DataServiceContext myDataServiceContext = ...
        e.Query = myDataServiceContext.Customers;
    }
}

VB.NET

Partial Public Class Form1
    Inherits Form
    Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
        oDataInstantFeedbackSource1.KeyExpression = "CustomerID"
        AddHandler oDataInstantFeedbackSource1.GetSource, AddressOf oDataInstantFeedbackSource1_GetSource
        gridControl1.DataSource = oDataInstantFeedbackSource1
    End Sub
    Private Sub oDataInstantFeedbackSource1_GetSource(ByVal sender As Object, ByVal e As GetSourceEventArgs)
        ' DataServiceContext myDataServiceContext = ...
        e.Query = myDataServiceContext.Customers
    End Sub
End Class

Note

A BadRequestException that occurs when data is being sorted, counted, etc., may be caused by the breaking change in Web API OData V6.0.0. For details, refer to the Global Query Setting section in the OData Web API documentation.

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Inheritance

Object

MarshalByRefObject

Component

ODataInstantFeedbackSource