React中classnames库使用示例

npm install classnames

bower install classnames

yarn add classnames

import classnames from ‘classnames';

var classNames = require('classnames');
classNames('foo', 'bar'); // => 'foo bar'

classNames('foo', { bar: true }); // => 'foo bar'
classNames({ 'foo-bar': true }); // => 'foo-bar'
classNames({ 'foo-bar': false }); // => ''
classNames({ foo: true }, { bar: true }); // => 'foo bar'
classNames({ foo: true, bar: true }); // => 'foo bar'
// lots of arguments of various types
classNames('foo', { bar: true, duck: false }, 'baz', { quux: true }); // => 'foo bar baz quux'
// other falsy values are just ignored
classNames(null, false, 'bar', undefined, 0, 1, { baz: null }, ''); // => 'bar 1'

var arr = ['b', { c: true, d: false }];`
classNames('a', arr); // => 'a b c'

let buttonType = 'primary';`
classNames({ [`btn-${buttonType}`]: true });

class Button extends React.Component {
// ...
render () {
var btnClass = 'btn';
if (this.state.isPressed) btnClass += ' btn-pressed';
else if (this.state.isHovered) btnClass += ' btn-over';
return <button className={btnClass}>{this.props.label}</button>;
}
}

var classNames = require('classnames');
class Button extends React.Component {
// ...
render () {
    var btnClass = classNames({
    btn: true,
   'btn-pressed': this.state.isPressed,
   'btn-over': !this.state.isPressed && this.state.isHovered
});
return <button className={btnClass}>{this.props.label}</button>;
}
}

var btnClass = classNames('btn', this.props.className, {
'btn-pressed': this.state.isPressed,
'btn-over': !this.state.isPressed && this.state.isHovered
});