Question

如何从React-Native获取onresume事件？我想在Android主要活动恢复时进行一些检查。我检查了RN的源代码，但是当应用程序恢复时似乎没有事件。

Answer 1

您可以使用 AppState
阅读本文件
https://facebook.github.io/react-native/docs/appstate.html

Answer 2

 This method is called every-time when user come back again this screen. 
 This method is same as in android onResume() method – Keshav Gera 6 mins ago    Delete


 render(){
 this.props.navigation.addListener(
    'didFocus',
       payload => {
         console.log("Payload is called .....................")
        }
  );

}

Answer 3

React Native提供 AppState 来告知应用程序是在前台还是在后台，并在状态更改时通知我们。

    import React, {Component} from 'react'
    import {AppState, Text} from 'react-native'

    class AppStateExample extends Component {

      state = {
        appState: AppState.currentState
      }

      componentDidMount() {
        AppState.addEventListener('change', this._handleAppStateChange);
      }

      componentWillUnmount() {
        AppState.removeEventListener('change', this._handleAppStateChange);
      }

      _handleAppStateChange = (nextAppState) => {
        if (this.state.appState.match(/inactive|background/) && nextAppState === 'active') {
          console.log('App has come to the foreground!')
        }
        this.setState({appState: nextAppState});
      }

      render() {
        return (
          <Text>Current state is: {this.state.appState}</Text>
        );
      }

    }

来源：https://facebook.github.io/react-native/docs/appstate.html

Answer 4

command: python code.py

Answer 5

我最终为此推出了自己的解决方案。实现起来非常简单。

确保所有活动都扩展同一类，并在其中进行以下操作：

import com.facebook.react.bridge.Arguments
import com.facebook.react.modules.core.DeviceEventManagerModule

override fun onResume() {
    super.onResume()

    val params = Arguments.createMap()
    params.putInt("rootViewTag", reactRootView!!.rootViewTag)
    val reactContext = reactRootView!!.reactInstanceManager!!.currentReactContext!!
    reactContext.getJSModule(DeviceEventManagerModule.RCTDeviceEventEmitter::class.java).emit("androidActivityResumed", params)
}

然后，在React方面执行以下操作：

import {DeviceEventEmitter} from 'react-native'

class MyComp extends React.Component {
  componentDidMount() {
    DeviceEventEmitter.addListener('androidActivityResumed', this._onAndroidActivityResumed)
  }

  componentWillUnmount() {
    DeviceEventEmitter.removeListener('androidActivityResumed', this._onAndroidActivityResumed)
  }

  _onAndroidActivityResumed = (e) => {
    if (e.rootViewTag === this.props.rootTag) {
      // Do whatever you want here
    }
  }
}

如何从React-Native获取onresume事件？

5 个答案: