Arrow功能与async和await in react native

Question

我正在尝试将数据保存AsyncStorage在react-native.我想保存它异步,所以使用async和await关键字.

  async onPositiveClickListener = () => {
    // user has completed product tour_end
    try {
      await AsyncStorage.setItem("@ProductTour:key", "true");
      const { navigate } = this.props.navigation;
      navigate("DashboardScreen");
    } catch (error) {
      console.log(error);
    }
  };

保存程序时出错

SyntaxError: Unexpected token, expected ( (40:32)
  38 |   };
  39 | 
> 40 |   async onPositiveClickListener = () => {
     |                                 ^
  41 |     // save user has completed product tour_end
  42 |     try {
  43 |       await AsyncStorage.setItem("@ProductTour:key", "true");
Hide Stack Trace
SyntaxError: Unexpected token, expected ( (40:32)
  38 |   };
  39 | 
> 40 |   async onPositiveClickListener = () => {
     |                                 ^
  41 |     // save user has completed product tour_end
  42 |     try {

Answer 1

异步命名的箭头函数应该声明为

const onPositiveClickListener = async () => {
    // user has completed product tour_end
    try {
      await AsyncStorage.setItem("@ProductTour:key", "true");
      const { navigate } = this.props.navigation;
      navigate("DashboardScreen");
    } catch (error) {
      console.log(error);
    }
  };