javascript - 不渲染组件 onClick

Question

我要渲染的组件：

import React, { Component } from 'react';

export default class QueryPrint extends Component {

    render() {
        console.log('working');

        return (
            <div>Hello</div>
        )
    }

}

试图调用它的组件：

import React, { Component } from 'react';
import { connect } from 'react-redux';

import {
    Button,

} from 'reactstrap';

import QueryPrint from './bq_print';

class QueryResults extends Component {
    constructor(props) {
        super(props);
        this.print = this.print.bind(this);
    }

    print() {
        console.log('Clicked');
        return (
            <QueryPrint />
        );
    }

    render() {
        return (
            <Button 
                className='cuts-btn' 
                color='success' 
                onClick={this.print}
            >
                Print
            </Button>
        )
    }
}

function mapStateToProps(state) {
    return {
        query_data: state.results.query_data
    }
}

export default connect (mapStateToProps, null)(QueryResults);

console.log('clicked')正在工作，但是应该在该方法中呈现的组件没有--noconsole.log('working')或<div>.

标签： javascriptreactjs

Answer 1

从点击回调返回一些东西没有效果。如果你想渲染一些东西，你可以在 render 方法中这样做。点击回调的工作是调用 this.setState()，然后它会启动渲染。

也许是这样的：

class QueryResults extends Component {
  constructor(props) {
    super(props);
    this.print = this.print.bind(this);
    this.state = {
      queryPrint: false,
    }
  }

  print() {
    console.log('Clicked');
    this.setState({ queryPrint: true })
  }

  render() {
    const { queryPrint } = this.state;
    return (
      <React.Fragment>
        {queryPrint && <QueryPrint />}
        <Button 
          className='cuts-btn' 
          color='success' 
          onClick={this.print}
        >
          Print
        </Button>
      </React.Fragment>
    )
  }
}