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

我认为这也是你需要的答案。此外,我在这里添加了所需的属性。每个输入组件都是函数。你需要在这里加入你自己的逻辑。

handleEmailChange: function(e) {
    this.setState({email: e.target.value});
},
handlePasswordChange: function(e) {
   this.setState({password: e.target.value});
},
formSubmit : async function(e) {
    e.preventDefault();
    // Form submit Logic
  },
render : function() {
      return (
        <form onSubmit={(e) => this.formSubmit(e)}>
          <input type="text" name="email" placeholder="Email" value={this.state.email} onChange={this.handleEmailChange} required />
          <input type="password" name="password" placeholder="Password" value={this.state.password} onChange={this.handlePasswordChange} required />
          <button type="button">Login</button>
        </form>);
},
handleLogin: function() {
    //Login Function
}

其他回答

下面是从表单中获取数据的最短方法,也是使用FormData避免id和ref的最佳方法

import React, { Component } from 'react'

class FormComponent extends Component {
  formSubmit = (event) => {
    event.preventDefault()
    var data = new FormData(event.target)
    let formObject = Object.fromEntries(data.entries())
    console.log(formObject)
  }
  render() {
    return (
      <div>
        <form onSubmit={this.formSubmit}>
          <label>Name</label>
          <input name="name" placeholder="name" />
          <label>Email</label>
          <input type="email" name="email" />
          <input type="submit" />
        </form>
      </div>
    )
  }
}
export default FormComponent

有几种方法可以做到这一点:

1)通过索引从数组的表单元素中获取值

handleSubmit = (event) => {
  event.preventDefault();
  console.log(event.target[0].value)
}

2)在html中使用name属性

handleSubmit = (event) => {
  event.preventDefault();
  console.log(event.target.elements.username.value) // from elements property
  console.log(event.target.username.value)          // or directly
}

<input type="text" name="username"/>

3)使用裁判

handleSubmit = (event) => {
  console.log(this.inputNode.value)
}

<input type="text" name="username" ref={node => (this.inputNode = node)}/>

完整的示例

class NameForm extends React.Component {
  handleSubmit = (event) => {
    event.preventDefault()
    console.log(event.target[0].value)
    console.log(event.target.elements.username.value)
    console.log(event.target.username.value)
    console.log(this.inputNode.value)
  }
  render() {
    return (
      <form onSubmit={this.handleSubmit}>
        <label>
          Name:
          <input
            type="text"
            name="username"
            ref={node => (this.inputNode = node)}
          />
        </label>
        <button type="submit">Submit</button>
      </form>
    )
  }
}

这是一个动态添加字段的示例。在这里,表单数据将使用React useState钩子通过输入名称键存储。

import React, { useState } from 'react' function AuthForm({ firebase }) { const [formData, setFormData] = useState({}); // On Form Submit const onFormSubmit = (event) => { event.preventDefault(); console.log('data', formData) // Submit here }; // get Data const getData = (key) => { return formData.hasOwnProperty(key) ? formData[key] : ''; }; // Set data const setData = (key, value) => { return setFormData({ ...formData, [key]: value }); }; console.log('firebase', firebase) return ( <div className="wpcwv-authPage"> <form onSubmit={onFormSubmit} className="wpcwv-authForm"> <input name="name" type="text" className="wpcwv-input" placeholder="Your Name" value={getData('name')} onChange={(e) => setData('name', e.target.value)} /> <input name="email" type="email" className="wpcwv-input" placeholder="Your Email" value={getData('email')} onChange={(e) => setData('email', e.target.value)} /> <button type="submit" className="wpcwv-button wpcwv-buttonPrimary">Submit</button> </form> </div> ) } export default AuthForm

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>

使用输入中的change事件来更新组件的状态,并在handllogin中访问它:

handleEmailChange: function(e) {
   this.setState({email: e.target.value});
},
handlePasswordChange: function(e) {
   this.setState({password: e.target.value});
},
render : function() {
      return (
        <form>
          <input type="text" name="email" placeholder="Email" value={this.state.email} onChange={this.handleEmailChange} />
          <input type="password" name="password" placeholder="Password" value={this.state.password} onChange={this.handlePasswordChange}/>
          <button type="button" onClick={this.handleLogin}>Login</button>
        </form>);
},
handleLogin: function() {
    console.log("EMail: " + this.state.email);
    console.log("Password: " + this.state.password);
}

工作小提琴。

此外,阅读文档,有一个完整的部分专门用于表单处理:表单

以前你也可以使用React的双向数据绑定助手mixin来实现同样的事情,但现在它被弃用了,取而代之的是设置值和更改处理程序(如上所述):

var ExampleForm = React.createClass({
  mixins: [React.addons.LinkedStateMixin],
  getInitialState: function() {
    return {email: '', password: ''};
  },
  handleLogin: function() {
    console.log("EMail: " + this.state.email);
    console.log("Password: " + this.state.password);
  },
  render: function() {
    return (
      <form>
        <input type="text" valueLink={this.linkState('email')} />
        <input type="password" valueLink={this.linkState('password')} />
        <button type="button" onClick={this.handleLogin}>Login</button>
      </form>
    );
  }
});

文档在这里:双向绑定助手。