What is the meaning of Yu Guangzhong's twilight poems, and what is the writing background at that time?

dusk

Yu Guangzhong

If dusk is a passport to loneliness

The west gate is closed to sunset.

Get on the horse in a hurry. Why?

I didn't come in, I just went out?

I was ambushed when I went through the customs.

The sunset glow changed completely as soon as it turned over.

Looking back, the west gate was closed.

————— I want to ask the side pawn on the butterfly several times.

I saw bats flapping their wings up and down.

Oh, an empty city.

This is a scene of Kuafu chasing the sun. Kuafu always wants to catch up with the sun, but the sun keeps going west, and dusk is the last pass. If he doesn't make it, Kuafu will come back in vain that day. People in the city have closed their doors and rested, and no one can be seen. So what Kuafu saw was an empty city.