Question OnParticleTrigger() enter particles always zero

Particle setting:
Colliders: None
Inside: Ignore
Outside: Ignore
Enter: Callback
Exit Ignore

Code (CSharp):

1. void OnParticleTrigger()
2.     {
3.         // get
4.         int numEnter = PS.GetTriggerParticles(ParticleSystemTriggerEventType.Enter,enter);
5.  
6.      
7.         Debug.Log(Time.time + "  " + numEnter);
8.         for (int i = 0; i < numEnter; i++)
9.         {
10.             ParticleSystem.Particle p = enter[i];
11.  
12.             int LayerMask = 1 << Constants.Layer_BodyPart;
13.             Collider[] hits = Physics.OverlapSphere(p.position, 1f, LayerMask);
14.             foreach (Collider c in hits)
15.                 Debug.Log(Time.time + "  " + c);
16.         }
17.     }

 

I find the problem, the colliders have to be the "target collider".

But I don't know there are many colliders moving in the 3d space in my game, I cannot fill the target collider list.