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react学习(四)- 表单,
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文本框
import React,{Component} from 'react';
class App extends Component {
constructor(props) {
super(props);
this.handleInputChange = this.handInputChange.bind(this);
this.handleTextareaChange = this.handleTextareaChange.bind(this);
this.state = {
inputValue: '',textareaValue = '';
};
}
handleInputChange(e) {
this.setState({
inputValue: e.target.value
});
}
handleTextareaChange(e) {
this.setState({
textareaValue: e.target.value
});
}
render() {
const {inputValue,textareaValue} = this.state;
return (
<div>
<p>单行输入框:<input type="text" value={inputValue} onChange={this.handleInputChange} /></p>
<p>多行输入框:<textarea value={e} onChange={this.handleTextareaChange} /></p>
)
}
}
单选按钮
import React,{Component} from 'react';
class App extends Component{
constructor(props) {
super(props);
this.handleChange = this.handleChange.bind(this);
this.state = {
radioValue: ''
};
}
handleChange(e) {
this.setState({
radioValue: e.target.value
});
}
render() {
const {radioValue} = this.state;
return (
<div>
<p>gender:</p>
<label>
male:
<input type="text" value="male" checked={radioValue === 'male'} onChange={this.handChange} />
</label>
<label>
female:
<input type="text" value="female" checked={radioValue === 'female'} onChange={this.handChange} />
</label>
)
}
}
复选框
import React,{Component} from 'react';
class App extends Component {
constructor(props) {
super(props);
this.handChange = this.handChange.bind(this);
this.state = {
coffee: []
};
}
handleChange(e) {
const {checked,value} = e.target;
let {coffee} = this.state;
if (checked && coffee.indexOf(value) === -1) {
coffee.push(value);
}
else {
coffee = coffee.filter(i => i !== value);
}
this.setState({
coffee
});
}
render() {
const {coffee} = this.state;
return (
<div>
<p>请选择你最喜欢咖啡:</p>
<label>
<input type="checkBox" value="Cappuccino"
checked={coffee.indexOf('Cappuccino') !== -1}
onChange={this.handleChange} />
Cappuccino
</label>
<br />
<label>
<input type="checkBox" value="CafeMocha"
checked={coffee.indexOf('CafeMocha') !== -1}
onChange={this.handleChange} />
CafeMocha
</label>
<br />
<label>
<input type="checkBox" value="CaffeLatte"
checked={coffee.indexOf('CaffeLatte') !== -1}
onChange={this.handleChange} />
CaffeLatte
</label>
<br />
<label>
<input type="checkBox" value="Machiatto"
checked={coffee.indexOf('Machiatto') !== -1}
onChange={this.handleChange} />
Machiatto
</label>
)
}
}
Select组件
import React,{Component} from 'react';
class App extends Component {
constructor(props) {
super(props);
this.handleChange = this.handleChange.bind(this);
this.state = {
area: ['beijing','shanghai']
};
}
handleChange(e) {
const {options} = e.target;
// 注意,这里返回的options是一个对象,并非数组
const area = Object.keys(options).filter(i => options[i].selected === true).map(i => options[i].value);
this.setState({
area: area
});
}
render() {
const {area} = this.state;
return (
<select multiple={true} value={area} onChange={this.handleChange}>
<option value="beijing">北京</option>
<option value="shanghai">上海</option>
<option value="hangzhou">杭州</option>
</select>
);
}
}
Select多选组件
import React,{Component} from 'react';
class App extends Component {
constructor(props) {
super(props);
this.handleChange = this.handleChange.bind(this);
this.state = {
area: ''
};
}
handleChange(e) {
this.setState({
area: e.target.value
});
}
render() {
const {area} = this.state;
return (
<select value={area} onChange={this.handleChange}>
<option value="beijing">北京</option>
<option value="shanghai">上海</option>
<option value="hangzhou">杭州</option>
</select>
);
}
}
原文链接:https://www.f2er.com/react/305009.html