ArcGIS Pro 3.3 API Reference Guide
ArcGIS.Desktop.Framework.Events Namespace / ApplicationClosingEvent Class
Members Example

In This Topic
    ApplicationClosingEvent Class
    In This Topic
    Occurs when the the application is attempting to shutdown and can be handled to cancel the closure.
    Object Model
    ApplicationClosingEvent ClassSubscriptionToken ClassSubscriptionToken Class
    Syntax
    public sealed class ApplicationClosingEvent : ArcGIS.Core.Events.AsyncPresentationEvent<CancelEventArgs> 
    Public NotInheritable Class ApplicationClosingEvent 
       Inherits ArcGIS.Core.Events.AsyncPresentationEvent(Of CancelEventArgs)
    Example
    Prevent ArcGIS Pro from Closing
    // There are two ways to prevent ArcGIS Pro from closing
    // 1. Override the CanUnload method on your add-in's module and return false.
    // 2. Subscribe to the ApplicationClosing event and cancel the event when you receive it
    
    internal class Module1 : Module
    {
    
      // Called by Framework when ArcGIS Pro is closing
      protected override bool CanUnload()
      {
        //return false to ~cancel~ Application close
        return false;
      }
    
      internal class Module2 : Module
      {
        public Module2()
        {
          ArcGIS.Desktop.Framework.Events.ApplicationClosingEvent.Subscribe(OnApplicationClosing);
        }
        ~Module2()
        {
          ArcGIS.Desktop.Framework.Events.ApplicationClosingEvent.Unsubscribe(OnApplicationClosing);
        }
    
        private Task OnApplicationClosing(System.ComponentModel.CancelEventArgs args)
        {
          args.Cancel = true;
          return Task.FromResult(0);
        }
    
        // cref: ARCGIS.DESKTOP.CORE.EVENTS.PROJECTOPENEDEVENT
        // cref: ARCGIS.DESKTOP.CORE.EVENTS.PROJECTOPENEDEVENT.SUBSCRIBE
        // cref: ARCGIS.DESKTOP.CORE.EVENTS.PROJECTOPENEDEVENT.UNSUBSCRIBE
        // cref: ARCGIS.DESKTOP.FRAMEWORK.CONTRACTS.MODULE.INITIALIZE
        // cref: ARCGIS.DESKTOP.FRAMEWORK.CONTRACTS.MODULE.UNINITIALIZE
        #region How to determine when a project is opened
        protected override bool Initialize() //Called when the Module is initialized.
        {
          ProjectOpenedEvent.Subscribe(OnProjectOpened); //subscribe to Project opened event
          return base.Initialize();
        }
    
        private void OnProjectOpened(ProjectEventArgs obj) //Project Opened event handler
        {
          MessageBox.Show($"{Project.Current} has opened"); //show your message box
        }
    
        protected override void Uninitialize() //unsubscribe to the project opened event
        {
          ProjectOpenedEvent.Unsubscribe(OnProjectOpened); //unsubscribe
          return;
        }
    Inheritance Hierarchy

    System.Object
       ArcGIS.Core.Events.EventBase
          ArcGIS.Core.Events.AsyncPresentationEvent<TPayload>
             ArcGIS.Desktop.Framework.Events.ApplicationClosingEvent

    Requirements

    Target Platforms: Windows 11, Windows 10

    ArcGIS Pro version: 3 or higher.
    See Also