ParticleSystem can't Simulate with start delay

When I set Start Delay=1, Start Lifttime=0.5, then use particleSystem.Simulate(m_RunningTime, true); to simulate particles. But it can’t simulate anything.

I guess, delay blocked simulation.

87774-2017-02-10-171117.png

How to solve the problem ?

from my experiment, it seems:
actual time = start delay * 2 + time

Most likely, it’s simply at the end of the animation. Either enable Looping while testing, or use the control panel in the Editor window to stop/start the particle animation.