小编Maj*_*olm的帖子

我试图在ReactJS中切换组件的状态,但我得到一个错误说明:

超出最大更新深度.当组件在componentWillUpdate或componentDidUpdate中重复调用setState时,可能会发生这种情况.React限制嵌套更新的数量以防止无限循环.

我没有在代码中看到无限循环,任何人都可以帮忙吗？

ReactJS组件代码:

import React, { Component } from 'react';
import styled from 'styled-components';

class Item extends React.Component {
    constructor(props) {
        super(props);     
        this.toggle= this.toggle.bind(this);
        this.state = {
            details: false
        } 
    }  
    toggle(){
        const currentState = this.state.details;
        this.setState({ details: !currentState }); 
    }

    render() {
        return (
            <tr className="Item"> 
                <td>{this.props.config.server}</td>      
                <td>{this.props.config.verbose}</td> 
                <td>{this.props.config.type}</td>
                <td className={this.state.details ? "visible" : "hidden"}>PLACEHOLDER MORE INFO</td>
                {<td><span onClick={this.toggle()}>Details</span></td>}
            </tr>
    )}
}

export default Item;

我是React Native的新手,真的无法弄清楚为什么我无法将状态从一个组件传递到另一个组件

export default class questions extends Component {
constructor(props){
    super(props);
    this.state={
        name: "stupidCount",
        val: 1}            
}

render(){
    const { navigate } = this.props.navigation;
    const { name2 } = this.state;
    return(
        <View style={styles.box}>
            <TouchableOpacity onPress={() => navigate('Question1',  stupidCount={name2})} >
                <Text style={styles.h1}> Question 1 </Text>
            </TouchableOpacity>

第二部分,'问题1'

export default class Question2 extends Component {
render(){
    const { navigate } = this.props.navigation;
    console.log(stupidCount.val);
    return(
        <View style={styles.box}>
            <Text style={styles.h1}>Question 2 </Text>
            <Text> state test {stupidCount.val}</Text>

非常感谢提前

我无法弄清楚为什么我的SQL选择查询一直失败 - 我是SQL的新手所以它可能是一个愚蠢的错误,但我无法在文档中找到答案.非常感谢提前

       // connect to db
    $mysqli = new mysqli("127.0.0.1", "maok08ab", "", "Portfolio");
    if ($mysqli->connect_errno) 
    {
        echo "Failed to connect to MySQL";
    }

    $username=$_POST["username"];
    $email=$_POST["email"];
    $hash=$_POST["password"];

    $query = "SELECT * FROM users WHERE username = '$username'";


    $result= mysqli_query($mysqli, $query);

    if ($result == FALSE)
    {
        apologize("something went wrong");
    }