return 到页面时尝试重置数据

Question

当return到页面

时，我正在尝试重置数据

这是我的一段代码

    componentDidMount(){
        
        this.checkIfAlreadyLoggedIn();
        
        this.willFocusSubscription = this.props.navigation.addListener(
            'willFocus',
            () => {
                this.setState({products:[],alreadyLoadedCount:0});
                this.checkIfAlreadyLoggedIn();
            }
          );
    }

    componentWillUnmount() {
        this.willFocusSubscription();
    }

页面已完全重新加载，但问题是当我返回上一页时显示以下错误

 ERROR  TypeError: this.willFocusSubscription is not a function. (In 'this.willFocusSubscription()', 'this.willFocusSubscription' is an instance of Object)

我把上面的代码也放在了上一页。但错误显示相同。

Answer 1

你能把'willFocus'改成'focus'吗，如下图所示，然后检查

Answer 2

我将 willfocus 更改为 didfocus 并将其删除 componentWillUnMount 。成功了

componentDidMount() {
   
....

 this.focusListener= this.props.navigation.addListener(
            'didFocus',
            () => {
                this.setState({products:[],alreadyLoadedCount:0});
                // loading page code
            }
  );
}

componentWillUnmount() {
   this.focusListener.remove();
}

return 到页面时尝试重置数据

Trying to reset data when return to the page

reactjs

native