React中setState方法异步问题

constructor(){
        super()
        this.state={
            userData:[]
        }
    }

this.setState(
   userData:this.getUserData()
)

this.setState(userData:this.getUserData(),()=>{
      //
      // 
})

 async getUserData(){
        await this.setState({
            userData:this.getUserData()
        });
 }