ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Desktop.Core.Events Namespace / ProjectOpenedEvent Class / Subscribe Method
The delegate that is subscribed to the event ProjectEventArgs
(optional) True indicates the delegate has a strong reference to the event, and must be unsubscribed when the subscription is no longer needed. False indicates a weak delegate reference to the event. (default value = false)
Example Version

Subscribe Method (ProjectOpenedEvent)
Subscribe to the ProjectOpenedEvent
Syntax

Parameters

action
The delegate that is subscribed to the event ProjectEventArgs
keepSubscriberAlive
(optional) True indicates the delegate has a strong reference to the event, and must be unsubscribed when the subscription is no longer needed. False indicates a weak delegate reference to the event. (default value = false)

Return Value

Example
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;
}
Requirements

Target Platforms: Windows 11, Windows 10

ArcGIS Pro version: 3 or higher.
See Also