ArcGIS Pro 3.4 API Reference Guide
ArcGIS.Desktop.Core.Events Namespace / ProjectOpenedEvent Class / Unsubscribe Method / Unsubscribe(Action<ProjectEventArgs>) Method
The delegate that is subscribed to the event
Example Version

Unsubscribe(Action<ProjectEventArgs>) Method
Unsubscribe the delegate from the ProjectOpenedEvent
Syntax
public static void Unsubscribe( 
   Action<ProjectEventArgs> action
)

Parameters

action
The delegate that is subscribed to the event
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