无法在React Native中的事件触发器上更改状态

Question

I am calling an event on react-native-voice to recognize the speech and calling an API and setting the state. But when I am setting a new value to a state array the array only have the new value instead of having the previous value. This is my code

constructor(props){
  super(props);
  this.state = {
  results = [];
}
Voice.onSpeechResults = this.onSpeechResults;
}

and I have a event which is been triggered to call an API like this.

onSpeechResults = e => {
        this._startRecognizing();
        //var joined = this.state.results.concat();
        getProductListingService(e.value[0]).then(data=>{
            let demoVar = Object.values(data);
            var newArray = this.state.results;
            newArray.push(demoVar[1]);
            this.setState({
                results:newArray
            })
           this.setState({
               show:true
           });
        });

    };

But when setting the state I am only able to get the new element been pushed into the array instead of the previous state. I have tried using concat , spread , and setting a new array. Stuck, Please help. :(

Answer 1

First declare your state like:

this.state = {
  results: []; // Don't use = for properties
}

second notice that if you setState() with same values that it already has, it doesn't set the state(and call render function).