屏幕出现时，将调用哪个生命周期事件? [英] Which lifecycle event is called when a screen appears?

问题描述

假设我有两个屏幕:

• 屏幕A
• 屏幕B

我最初登陆屏幕A .单击Button时，我导航到屏幕B .当我按下Back Button时，我再次导航到屏幕A .

I am initially landed on Screen A. When I click on a Button I navigate to Screen B. When I press Back Button, I am again navigated to Screen A.

如上所述，当我导航到屏幕A 时，我想打电话给动作创建者.

I want to call an action creator when I am navigated to Screen A as mentioned in above scenario.

我只想知道每次显示屏幕时都会调用哪个生命周期事件.

I just want to know that which lifecycle event will be called every time when a screen is presented.

没有像componentWillAppear()这样的事件吗?

注意:我正在将react-native和react-navigation用于导航.

Note: I am using react-native with react-navigation for navigation.

推荐答案

现在可以通过其侦听器进行简单的反应导航:

This can now be done with plain react navigation via their listeners:

在组件A中:

componentDidMount = () => {
  this._componentFocused();

  this._sub = this.props.navigation.addListener(
    'didFocus',
    this._componentFocused
  );
}

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

_componentFocused = () => {
  this.setState({dataToShow});
}

反应导航docs-Lifecycle

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