React 把 input,textarea 和 select 三个组件做了抽象和封装,他们的用法变得非常统一,你基本上可以当做同一个组件来用。 他们现在有统一的 value 属性 和 onChange 事件,现在对于这三种组件你都可以这样写 <input type='text'name='intro'id='intro'value={this.state.email} onChange={this.handleEmail} /> ...
AI代码解释 functionuseInputValue(initialValue){let[value,setValue]=useState(initialValue);letonChange=useCallback(function(event){setValue(event.currentTarget.value);},[]);return{value,onChange};} 当然这随着表单项变多,会状态管理的问题,React官方提供的useReducerhooks就是为了解决这个问题而生的,useFormSt...
AI代码解释 import{useRef}from'react';exportdefault()=>{constinputRef=useRef({value:0})return(<div><h1>测试</h1><input type="text"ref={inputRef}/><button onClick={()=>{console.log(inputRef.current.value)}}>获取input 值</button><button onClick={()=>{inputRef.current.focus()}}>获...
}else{dispatch({ type:"NO_VALUE"});} };return(<>{state.isModalOpen? <Modal modalContent={state.modalContent} /> :""}<form className="form"onSubmit={handleSubmit}> <div> <input type="text"value={name} onChange={(e) =>{ setName(e.target.value); }}></input> </div> <button ...
var MyComponent = React.createClass({ getInitialState() { return { /* initial state */ }; }, }); 问题30:如何有条件地向 React 组件添加属性? 主题: React难度: ⭐⭐⭐⭐ 对于某些属性,React 非常聪明,如果传递给它的值是虚值,可以省略该属性。例如: var InputComponent = React.createClass(...
Default value: "textarea" Widget for rendering input fielddefaultValue : stringDefault value: "" Initial text for inputdisabled : booleanDefault value: false Disables widget, i.e. during form submissionmaxOptions : numberDefault value: 6
this.setState({ value: event.target.value }) } render () { return <input type...
initialValue Initial value of the Spinner StringNumber 0 inputProps Customized TextInput Component props Object null Could overwrite other props leftButtonProps Customized left button (Touchable Component) props Object null Could overwrite other props maxLength Limits the maximum number of characters that ...
) { const name = this.inputDemo.value; document.getElementById('disp').innerHTML = name; } render() { return( <div> Name: <input type="text" ref={input => this.inputDemo = input} /> <button name="Click" onClick={this.display}>Click</button> <h2>He...
```jsxconstForm = () => {const[value, setValue] = useState('');consthandleChange = (event) => {setValue(event.target.value);};return(<inputvalue={value} onChange={handleChange} />);};// Usage<Form />``` 14. 非受控...