Question

Im React newbie :)。我创建了一个非常简单的React控件，名为CustomInput，但是当单击该按钮时，onChange处理程序启动了，但是当它的finfin值在handller中是正常的但它没有在表单上更新（或被覆盖））。

问题出在哪里？

我的CustomInput代码如下：

"use strict";

var React = require('react');

var CustomInput = React.createClass({
    propTypes: {
        value: React.PropTypes.string.isRequired,
        name: React.PropTypes.string.isRequired        
        /*
    error: React.PropTypes.string
    label: React.PropTypes.string.isRequired,
    onChange: React.PropTypes.func.isRequired,
    placeholder: React.PropTypes.string,
    value: React.PropTypes.string,    
    */
    },

    getInitialState: function() {
        debugger;
        return {
            value: '',
            errors: {},
            dirty: false
        };
    },

    onChange: function(event) {
        debugger;        
        var value = event.target.value + "%";
        this.state.value = value;
        console.log("onChange: "+this.state.value);
        return this.setState({value: this.state.value});        
    },

    render: function () {
        var wrapperClass = 'form-group';
        if (this.props.error && this.props.error.length > 0) {
            wrapperClass += " " + 'has-error';
        }

        var textStyle = { "text-align": "center" };

        return (
        <div className={wrapperClass}>
        <label htmlFor={this.props.name}>{this.props.label}</label>
        <div className="field">
        <input type="text"
        name={this.props.name}
        className="form-control"
        placeholder="enter value"
        ref={this.props.name}
        value={this.props.value}
        onChange={this.onChange}
        style={textStyle}
        />
        <div className="input">{this.props.error}</div>
        </div>
        </div>
    );
}
});

module.exports = CustomInput;

更新1：我的包含CustomInput控件的组件如下所示：

"use strict";

var React = require('react');
var peopleApi = require('../../../api/peopleApi');
var CustomInput = require('../common/customInput');
//var PeopleList = require('./peopleList');

var AuthorPage = React.createClass({
    getInitialState: function() {
        //debugger; 
        return {
            person: {}
        };
    },

    componentDidMount: function() {
        if (this.isMounted()) {
           //debugger; 
           this.setState({person: peopleApi.getPersonById(this.props.personId)});
        }
    },

    render: function() {
        return (
            <div>
                <h1>Person</h1>
                <CustomInput value={this.state.person.id} name="personId" error = "" label= "ID"/>
                <CustomInput value={this.state.person.name} name="personName" error="" label= "Name"/>
                <CustomInput value={this.state.person.salary} name="personSalary" error="" label="Pensja"/>
                <CustomInput value={this.state.person.spelnieniePercent} name="personSpelnienie" error="" label= "Spelnienie [%]"/>
                <CustomInput value={this.state.person.dataUrodzenia} name="personDataUrodzenia" error="" label="Data urodzenia:"/>
            </div>
        );
    }
});

module.exports = AuthorPage;

更新2：更新函数onChange（）后：

onChange: function(event) {
    debugger;        
    var value = event.target.value + "%";
    //this.state.value = value;
    //console.log("onChange: "+this.state.value);
    return this.setState({ value }, () => console.log("onChange: ", this.state.value));                
},

但效果仍然相同：新值被原始值覆盖。

Answer 1

onChange: function(event) {
    var value = event.target.value + "%";
    // this.state.value = value; << dont do this
    return this.setState({ value }, () => console.log("onChange: ", this.state.value));        
},

永远不要直接改变状态，否则setState将无法触发重新渲染，因为它认为组件已经使用新状态更新。

单击按钮时不会更新输入

1 个答案: