DevExpress ASP.NET controls provide an advanced client-side API that increases web application efficiency via a combination of server-side and client-side processing. Client-side events allow you to perform web application logic on the client in response to end-user manipulations of a control.
Client-Side Events Editor (for WebForms only)
Use the Client-Side Events editor (available in the control’s Designer, as shown below) to write a client-side event handler. The editor displays a list of available client-side events, and allows you to write an event handler implementation within it. The editor automatically adds the code to the markup.
A control’s Designer can be launched in the following ways.
Click the control's Smart Tag and select Designer... from the invoked drop down list.
Right-click the control and choose Designer... in the invoked context menu.
Select the control, open its Properties window, and select Designer... within the Command Panel.
Select the control, open its Properties window, and click the ClientSideEvents property's ellipsis button (shown below) or a client-side event’s ellipsis.
To create an event handler, choose the required event on the left, and write the event handler implementation on the right. Note that the Designer automatically generates a default event handler signature within the Event Handler Body pane.
Click OK to automatically add the corresponding aspx code to the markup.