对象作为React子对象无效

Question

我收到以下错误.我可以看到我必须返回数组而不是对象.但我真的不确定如何解决它.提前致谢

对象作为React子对象无效.如果您要渲染子集合,请使用数组,或使用React附加组件中的createFragment(object)包装对象.检查渲染方法View.

constructor(props){
    super(props);
    this.state = {timeElapsed: null};
  }

startStopButton(){
    return <TouchableHighlight underlayColor="gray" onPress={this.handleStartPress.bind(this)}>
        <Text>Start</Text>
      </TouchableHighlight>
  }

handleStartPress(){
      var startTime = new Date();




      setInterval(()=>{
        this.setState({timeElapsed: new Date()})
      }, 1000);
  }
render(){
return(
  <View style={styles.container}>
    <View style={[styles.header]}>
      <View style={[styles.timerContainer, this.borderColor('#ff6666')]}>
        {this.state.timeElapsed}
      </View>
      <View style={[styles.buttonsContainer, this.borderColor('#558000')]}>
        {this.startStopButton()}
        {this.lapButton()}
      </View>
    </View>
  </View>
);


}

Answer 1

timeElapsed是一个对象,React不知道如何渲染它:

  <View style={[styles.timerContainer, this.borderColor('#ff6666')]}>
    {this.state.timeElapsed}
  </View>

尝试更改this.state.timeElapsed字符串,例如:

  <View style={[styles.timerContainer, this.borderColor('#ff6666')]}>
    {this.state.timeElapsed.toString()}
  </View>