ListViewProcessCurrentObjectController.CustomHandleProcessSelectedItem Event

Occurs when an end-user double-clicks an object or presses Enter for a selected object in a WinForms application or clicks an object in a Web application in a List Editor.

Namespace: DevExpress.ExpressApp.SystemModule

Assembly: DevExpress.ExpressApp.v18.2.dll

Declaration

public event EventHandler<HandledEventArgs> CustomHandleProcessSelectedItem
Public Event CustomHandleProcessSelectedItem As EventHandler(Of HandledEventArgs)

The event handler receives an argument of the HandledEventArgs type.

Subscribe to the CustomHandleProcessSelectedItem event to change how XAF processes a List Editor's object when a user attempts to open the object.

XAF opens the selected object's Detail View if the object is in a List View. If an end-user selects an object in a Lookup List View, XAF links the object to the current Detail View's object. To cancel this default processing, create the CustomHandleProcessSelectedItem event handler and set the HandledEventArgs.Cancel parameter to true. You can also use the handler to execute an Action - for example, to open a View for the selected object.

The EmployeeLookupListViewController below changes the default behavior for certain employees in a Lookup List View. If an employee is on leave, the end-user cannot link the employee to the current object, and the employee's Detail View opens. Otherwise, the end-user can link the employee to the master object.

using DevExpress.ExpressApp;
using DevExpress.ExpressApp.SystemModule;
using System.ComponentModel;
// ...
public class EmployeeLookupListViewController : ViewController {
    private ListViewProcessCurrentObjectController processCurrentObjectController;
    private OpenObjectController openObjectController;

    public EmployeeLookupListViewController() {
        TargetViewId = "Employee_LookupListView";
    }
    protected override void OnActivated() {
        base.OnActivated();
        processCurrentObjectController = Frame.GetController<ListViewProcessCurrentObjectController>();
        openObjectController = Frame.GetController<OpenObjectController>();
        if(processCurrentObjectController != null) {
          processCurrentObjectController.CustomHandleProcessSelectedItem += EmployeeLookupListViewController_CustomHandleProcessSelectedItem;
        }
    }
    private void EmployeeLookupListViewController_CustomHandleProcessSelectedItem(
        object sender, HandledEventArgs e) {
        Employee currentEmployee = (Employee)View.CurrentObject;
        if(currentEmployee.IsOnLeave) {
          e.Handled = true;
          if(openObjectController != null) {
            openObjectController.SetObjectToOpen(View.CurrentObject);
            if(openObjectController.OpenObjectAction.Active && openObjectController.OpenObjectAction.Enabled) {
              openObjectController.OpenObjectAction.DoExecute();
            }
          }
        }
    }
    protected override void OnDeactivated() {
        base.OnDeactivated();
        if(processCurrentObjectController != null) {
          processCurrentObjectController.CustomHandleProcessSelectedItem -= EmployeeLookupListViewController_CustomHandleProcessSelectedItem;
          processCurrentObjectController = null;
        }
        openObjectController = null;
    }
}

See Also