"The event can only appear on the left hand side of `+=' or `-=' operator"

Questions & Answers
1

Hey, iam trying to sync some values to an action event by doing this:

public event System.Action<Vector3> OnTriggerBail
		{
			[System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.Synchronized)]
			add
			{
				this.OnTriggerBail = (System.Action<Vector3>)System.Delegate.Combine(this.OnTriggerBail, value);
			}
			[System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.Synchronized)]
			remove
			{
				this.OnTriggerBail = (System.Action<Vector3>)System.Delegate.Remove(this.OnTriggerBail, value);
			}
		}

		public event Action OnTriggerLanding
		{
			[System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.Synchronized)]
			add
			{
				this.OnTriggerLanding = (Action)System.Delegate.Combine(this.OnTriggerLanding, value);
			}
			[System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.Synchronized)]
			remove
			{
				this.OnTriggerLanding = (Action)System.Delegate.Remove(this.OnTriggerLanding, value);
			}
		}

but iam getting the error:
The event OnTriggerBail' can only appear on the left hand side of +=’ or `-=’ operator

any idea why?

2

You are declaring an accessor for the OnTriggerBail event, but you use it inside the add and remove. You have to create a private event onTriggerBail you will be able to use inside your accessors (the same apply for your other event)

     private event System.Action<Vector3> onTriggerBail;

     public event System.Action<Vector3> OnTriggerBail
     {
         [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.Synchronized)]
         add
         {
             onTriggerBail = (System.Action<Vector3>)System.Delegate.Combine(onTriggerBail, value);
         }
         [System.Runtime.CompilerServices.MethodImpl(System.Runtime.CompilerServices.MethodImplOptions.Synchronized)]
         remove
         {
             onTriggerBail = (System.Action<Vector3>)System.Delegate.Remove(onTriggerBail, value);
         }
     }