UnboundSource.ValueNeeded Event

Occurs when a value is requested from the UnboundSource.

Namespace: DevExpress.Data

Assembly: DevExpress.Data.v18.2.dll

Declaration

C#

public event EventHandler<UnboundSourceValueNeededEventArgs> ValueNeeded

VB.NET

Public Event ValueNeeded As EventHandler(Of UnboundSourceValueNeededEventArgs)

Event Data

The ValueNeeded event's data class is UnboundSourceValueNeededEventArgs. The following properties provide information specific to this event:

Property	Description
PropertyIndex
PropertyName	Gets the name of the property whose value is requested.
RowIndex	Gets the row index of the value.
Tag	Gets an object that contains data associated with the value.
Value	Specifies the value which is requested.

The event data class exposes the following methods:

Method
SetValue<T>(T)

Remarks

Handle this event to obtain data from your data source. An example is provided in the UnboundSource topic.

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference to the ValueNeeded event.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

XDL_how-to-utilize-the-unboundsource-component-in-code-t474976/CS/UnboundDS-Code/Form1.cs#L25

unboundSourceProperty2});
unboundDS.ValueNeeded += unboundDS_ValueNeeded;
unboundDS.ValuePushed += unboundDS_ValuePushed;

VB.NET

XDL_how-to-utilize-the-unboundsource-component-in-code-t474976/VB/UnboundDS-Code/Form1.vb#L25

unboundDS.Properties.AddRange(New DevExpress.Data.UnboundSourceProperty() { unboundSourceProperty1, unboundSourceProperty2})
AddHandler unboundDS.ValueNeeded, AddressOf unboundDS_ValueNeeded
AddHandler unboundDS.ValuePushed, AddressOf unboundDS_ValuePushed