我在渲染函数中有一个简单的表单,如下所示:

render : function() {
      return (
        <form>
          <input type="text" name="email" placeholder="Email" />
          <input type="password" name="password" placeholder="Password" />
          <button type="button" onClick={this.handleLogin}>Login</button>
        </form>
      );
    },
handleLogin: function() {
   //How to access email and password here ?
}

我应该在我的handleLogin: function(){…}访问电子邮件和密码字段?


当前回答

我建议采取以下方法:

import {Autobind} from 'es-decorators';

export class Form extends Component {

    @Autobind
    handleChange(e) {
        this.setState({[e.target.name]: e.target.value});
    }

    @Autobind
    add(e) {
        e.preventDefault();
        this.collection.add(this.state);
        this.refs.form.reset();
    }

    shouldComponentUpdate() {
        return false;
    }

    render() {
        return (
            <form onSubmit={this.add} ref="form">
                <input type="text" name="desination" onChange={this.handleChange}/>
                <input type="date" name="startDate" onChange={this.handleChange}/>
                <input type="date" name="endDate" onChange={this.handleChange}/>
                <textarea name="description" onChange={this.handleChange}/>
                <button type="submit">Add</button>
            </form>
        )
    }

}

其他回答

es6析构的更清晰的例子

class Form extends Component {
    constructor(props) {
        super(props);
        this.state = {
            login: null,
            password: null,
            email: null
        }
    }

    onChange(e) {
        this.setState({
            [e.target.name]: e.target.value
        })
    }

    onSubmit(e) {
        e.preventDefault();
        let login = this.state.login;
        let password = this.state.password;
        // etc
    }

    render() {
        return (
            <form onSubmit={this.onSubmit.bind(this)}>
                <input type="text" name="login" onChange={this.onChange.bind(this)} />
                <input type="password" name="password" onChange={this.onChange.bind(this)} />
                <input type="email" name="email" onChange={this.onChange.bind(this)} />
                <button type="submit">Sign Up</button>
            </form>
        );
    }
}

下面是我使用单个inputChangeHandler收集多个表单输入的方法

import React from "react";

const COLORS = ["red", "orange", "yellow", "purple", "green", "white", "black"];

export default function App() {

  const initialFormFields = {
    name: undefined,
    email: undefined,
    favourite_color: undefined
  };
  const [formInput, setFormInput] = React.useState(initialFormFields);

  function inputChangeHandler(event) {
    setFormInput(prevFormState => ({
      ...prevFormState,
      [event.target.name]: event.target.value
    }))
  };

  return (
    <div className="App">
      <form>
        <label>Name: <input name="name" type="text" value={formInput.name} onChange={inputChangeHandler}/></label>
        <label>Email: <input name="email" type="email" value={formInput.email} onChange={inputChangeHandler}/></label>
        <div>
          {COLORS.map(color => <label><input type="radio" name="favourite_color" value={color} key={color} onChange={inputChangeHandler}/> {color} </label>)}
        </div>
      </form>

      <div>
        Entered Name: {formInput.name}
        Entered Email: {formInput.email}
        Favourite Color: {formInput.favourite_color}
      </div>
    </div>
  );
}

如果你在项目中使用Redux,你可以考虑使用这个更高阶的组件https://github.com/erikras/redux-form。

不需要使用引用,你可以使用事件访问

function handleSubmit(e) {
    e.preventDefault()
    const {username, password } = e.target.elements
    console.log({username: username.value, password: password.value })
}

<form onSubmit={handleSubmit}>
   <input type="text" id="username"/>
   <input type="text" id="password"/>
   <input type="submit" value="Login" />
</form>

我像这样使用React Component state:

<input type="text" name='value' value={this.state.value} onChange={(e) => this.handleChange(e)} />

handleChange(e){
   this.setState({[e.target.name]: e.target.value})
}`