对于表单的处理,react的处理和原生很相像,所以没有什么多说的,就是看例子吧~ 以下就是input, textarea, select的用法,其实都一样,把state的值挂载到相应位置的value上,并且监听相应的事件即可,注意事件的写法onChange驼峰哦。回调函数的第一个参数是event哦,原生event对象可以做一些例如消除默认行为和停止冒泡的事情。这些被控制的组件叫做controlled components。
然后你会发现这也太麻烦啦,每一个表单控件我都得写一个handler区处理它,这样的话不仅麻烦而且和原生代码以及非react得库难以整合,所以有uncontrolled components, 来改善这一情况,会另起文章来记录~
class NameForm extends React.Component { constructor(props) { super(props); this.state = {value: ''}; this.handleChange = this.handleChange.bind(this); this.handleSubmit = this.handleSubmit.bind(this); } handleChange(event) { this.setState({value: event.target.value}); } handleSubmit(event) { alert('A name was submitted: ' + this.state.value); event.preventDefault(); } render() { return ( <form onSubmit={this.handleSubmit}> <label> Name: <input type="text" value={this.state.value} onChange={this.handleChange} /> </label> <input type="submit" value="Submit" /> </form> ); } }
class EssayForm extends React.Component { constructor(props) { super(props); this.state = { value: 'Please write an essay about your favorite DOM element.' }; this.handleChange = this.handleChange.bind(this); this.handleSubmit = this.handleSubmit.bind(this); } handleChange(event) { this.setState({value: event.target.value}); } handleSubmit(event) { alert('An essay was submitted: ' + this.state.value); event.preventDefault(); } render() { return ( <form onSubmit={this.handleSubmit}> <label> Name: <textarea value={this.state.value} onChange={this.handleChange} /> </label> <input type="submit" value="Submit" /> </form> ); } }
class FlavorForm extends React.Component { constructor(props) { super(props); this.state = {value: 'coconut'}; this.handleChange = this.handleChange.bind(this); this.handleSubmit = this.handleSubmit.bind(this); } handleChange(event) { this.setState({value: event.target.value}); } handleSubmit(event) { alert('Your favorite flavor is: ' + this.state.value); event.preventDefault(); } render() { return ( <form onSubmit={this.handleSubmit}> <label> Pick your favorite La Croix flavor: <select value={this.state.value} onChange={this.handleChange}> <option value="grapefruit">Grapefruit</option> <option value="lime">Lime</option> <option value="coconut">Coconut</option> <option value="mango">Mango</option> </select> </label> <input type="submit" value="Submit" /> </form> ); } }