我的组件很简单:
import React, {Component} from 'react';
import {connect} from 'react-redux';
import {bindActionCreators} from 'redux';
import * as instanceActions from '../../../store/instances/instancesActions';
class InstanceDetailsPage extends Component {
componentWillReceiveProps(nextProps) {
console.log('will receive props');
if (nextProps.id !== this.props.id){
this.updateInstanceDetails();
}
}
updateInstanceDetails = () => {
this.props.actions.loadInstance(this.props.instance);
};
render() {
return (
<h1>Instance - {this.props.instance.name}</h1>
);
}
}
function getInstanceById(instances, instanceId) {
const instance = instances.filter(instance => instance.id === instanceId);
if (instance.length) return instance[0];
return null;
}
function mapStateToProps(state, ownProps) {
const instanceId = ownProps.match.params.id;
let instance = {id: '', name: ''};
if (instanceId && state.instances.length > 0) {
instance = getInstanceById(state.instances, instanceId) || instance;
}
return {
instance,
};
}
function mapDispatchToProps(dispatch) {
return {
actions: bindActionCreators(instanceActions, dispatch)
};
}
export default connect(mapStateToProps, mapDispatchToProps)(InstanceDetailsPage);
我非常确定我的reducer不会改变状态:
import * as types from '../actionTypes';
import initialState from '../initialState';
export default function instancesReducer(state = initialState.instances, action) {
switch (action.type){
case types.LOAD_INSTANCES_SUCCESS:
return action.instances.slice(); // I probably don't event need the .slice() here, but just to be sure.
default:
return state;
}
}
我肯定知道触发道具的状态更改是因为我在render方法上登录了
this.props
,并且道具更改了两次!这样,
componentWillReceiveProps
甚至都没有被调用过。是什么原因造成的?
最佳答案
有一些原因将导致不调用componentWillReceiveProps的原因,
如果未从redux商店接收到新的props对象
此外,如果安装了组件,则不会调用这些方法。因此,您可能会看到组件更新,但实际上只是安装和卸载。要解决此问题,请查看渲染该组件的父级,并检查它是否正在使用其他键渲染该组件,或者是否存在某种条件渲染,该渲染可能返回false并导致对其进行卸载。
关于reactjs - 在redux Prop 更改时未调用componentWillReceiveProps,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/48689169/