constructor(props){

    super(props);

    this.state = {

      title:'不透明触摸'

    }

    this.activiEvent = this.activiEvent.bind(this);

  }

  render() {

    return (

      <View>

        {/*

        onPress={this.renderPress()}

        onPress={()=>this.activiEvent('点击')}

        onPressIn={()=>this.activiEvent('按下')}

        onPressOut={()=>this.activiEvent('抬起')}

        onLongPress={()=>this.activiEvent('长按')}

        */}

        <View>

          <TouchableOpacity activeOpacity={0.5}

          onPress={()=>this.activiEvent('点击')}

          onPressIn={()=>this.activiEvent('按下')}

          onPressOut={()=>this.activiEvent('抬起')}

          onLongPress={()=>this.activiEvent('长按')}

          >

            <View>

              <Text>我是文本但可以点击常用事件</Text>

            </View>

          </TouchableOpacity>

        </View>

        <View>

          <Text>{this.state.title}</Text>{/*标签内取值要用花括号*/}

        </View>

      </View>

    );

  }

  renderPress(){

    {/*还没点击就弹窗了 花括号注释不能写到函数外 标签内注释用花括号 标签外可以用// */}

    Alert.alert('iOS')

  }

  activiEvent(event){

    this.setState({

      title:event

    })

  }