我正在考虑使用 react-select作为城市选择器的选择器,用户可以在其中选择一个或多个城市来过滤一些数据。这是在我的页面中呈现的屏幕截图:
城市列表可能很大,如果一次选择大量城市,我不希望选择器超出其蓝色容器。这是我现在模拟时发生的情况:
我不太喜欢它!我能想到的一种替代方法是呈现“选择的 4 个城市”而不是整个列表。这将在页面上具有可预测的大小。
这如何用 react-select
完成?
最佳答案
注意:此答案适用于 react-select v1。查看answer by NearHuscarl v3 的解决方案。
渲染“选择了 N 个项目”
这可以通过 valueRenderer
和 className
属性以及最少量的 CSS 来实现。
这里我正常显示前三个选择,然后在选择了 4 个以上项目时显示“已选择 N 个项目”。除了“已选择 N 个项目”之外,显示删除选择图标 (×) 是没有意义的,因此我也删除了它(使用 CSS)。
class App extends React.Component {
state = {
value: [],
}
className = () => {
const baseClassName = 'my-react-select';
if (this.state.value.length <= 3) {
return baseClassName;
}
return `${baseClassName} ${baseClassName}--compact`;
}
handleChange = (value) => {
this.setState({ value });
}
renderValue = (option) => {
// The first three selections are rendered normally
if (this.state.value.length <= 3) {
return option.label;
}
// With more selections, render "N items selected".
// Other than the first one are hidden in CSS.
return <span>{this.state.value.length} items selected</span>;
}
render() {
return (
<Select
className={this.className()}
multi
onChange={this.handleChange}
options={[
{ value: 'zero', label: 'Zero' },
{ value: 'one', label: 'One' },
{ value: 'two', label: 'Two' },
{ value: 'three', label: 'Three' },
{ value: 'four', label: 'Four' },
{ value: 'five', label: 'Five' },
{ value: 'six', label: 'Six' },
{ value: 'seven', label: 'Seven' },
{ value: 'eight', label: 'Eight' },
{ value: 'nine', label: 'Nine' },
]}
value={this.state.value}
valueRenderer={this.renderValue}
/>
);
}
}
ReactDOM.render(<App />, document.getElementById('root'));
.my-react-select {
/* Custom styles */
}
.my-react-select--compact .Select-value:first-child {
font-style: italic;
}
.my-react-select--compact .Select-value:first-child .Select-value-icon,
.my-react-select--compact .Select-value:nth-child(n+2) {
display: none;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<script src="https://unpkg.com/prop-types@15.5.10/prop-types.js"></script>
<script src="https://unpkg.com/classnames@2.2.5/index.js"></script>
<script src="https://unpkg.com/react-input-autosize@2.0.0/dist/react-input-autosize.js"></script>
<script src="https://unpkg.com/react-select@1.3.0/dist/react-select.js"></script>
<link rel="stylesheet" href="https://unpkg.com/react-select@1.3.0/dist/react-select.css">
<div id="root"></div>
替代方法
查看您的屏幕截图,似乎有空间可以显示最多四个选择而不会使选择器溢出。 选择了4个以上的城市时,您可以正常显示前3个选择,然后再显示“+ n”。
从用户体验的 Angular 来看,我认为正常显示前 3 个左右的选择是很好的。如果在选择第 4 个城市后,所有选择突然隐藏在文本“4 items selected”后面,这会让人感到困惑。 这个解决方案与第一个非常相似。 这是显示选择的另一种方法: 从 UX 的 Angular 来看,显示“+ 1 more”而不是显示值有点傻,所以在我看来这是最好的选择。
className
Prop 现在只是一个字符串。 renderValue
方法和 CSS 选择器有点不同。class App extends React.Component {
state = {
value: [],
}
handleChange = (value) => {
this.setState({ value });
}
renderValue = (option) => {
// The first three values are rendered normally
if (this.state.value.indexOf(option) < 3) {
return option.label;
}
// Render the rest as "+ N more".
// Other than the first one are hidden in CSS.
return <span>+ {this.state.value.length - 3} more</span>;
}
render() {
return (
<Select
className='my-react-select'
multi
onChange={this.handleChange}
options={[
{ value: 'zero', label: 'Zero' },
{ value: 'one', label: 'One' },
{ value: 'two', label: 'Two' },
{ value: 'three', label: 'Three' },
{ value: 'four', label: 'Four' },
{ value: 'five', label: 'Five' },
{ value: 'six', label: 'Six' },
{ value: 'seven', label: 'Seven' },
{ value: 'eight', label: 'Eight' },
{ value: 'nine', label: 'Nine' },
]}
value={this.state.value}
valueRenderer={this.renderValue}
/>
);
}
}
ReactDOM.render(<App />, document.getElementById('root'));
/* If you change the amount of how many selections are shown normally,
* be sure to adjust these selectors accordingly. */
.my-react-select .Select-value:nth-child(4) {
font-style: italic;
}
.my-react-select .Select-value:nth-child(4) .Select-value-icon,
.my-react-select .Select-value:nth-child(n+5) {
display: none;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<script src="https://unpkg.com/prop-types@15.5.10/prop-types.js"></script>
<script src="https://unpkg.com/classnames@2.2.5/index.js"></script>
<script src="https://unpkg.com/react-input-autosize@2.0.0/dist/react-input-autosize.js"></script>
<script src="https://unpkg.com/react-select@1.3.0/dist/react-select.js"></script>
<link rel="stylesheet" href="https://unpkg.com/react-select@1.3.0/dist/react-select.css">
<div id="root"></div>
renderValue
方法再次有点不同。 CSS 选择器现在有点丑陋和复杂,但它们可以工作。class App extends React.Component {
state = {
value: [],
}
handleChange = (value) => {
this.setState({ value });
}
renderValue = (option) => {
// The first four values are rendered normally
if (this.state.value.length <= 4) {
return option.label;
}
// The first 3 values are rendered normally when
// more than 4 selections have been made
if (this.state.value.indexOf(option) < 3) {
return option.label;
}
// Render the rest as "+ N more".
// Other than the first one are hidden in CSS.
return <span>+ {this.state.value.length - 3} more</span>;
}
render() {
return (
<Select
className='my-react-select'
multi
onChange={this.handleChange}
options={[
{ value: 'zero', label: 'Zero' },
{ value: 'one', label: 'One' },
{ value: 'two', label: 'Two' },
{ value: 'three', label: 'Three' },
{ value: 'four', label: 'Four' },
{ value: 'five', label: 'Five' },
{ value: 'six', label: 'Six' },
{ value: 'seven', label: 'Seven' },
{ value: 'eight', label: 'Eight' },
{ value: 'nine', label: 'Nine' },
]}
value={this.state.value}
valueRenderer={this.renderValue}
/>
);
}
}
ReactDOM.render(<App />, document.getElementById('root'));
/* If you change the amount of how many selections are shown normally,
* be sure to adjust these selectors accordingly. */
.my-react-select .Select-value:nth-child(4):not(:nth-last-child(2)) {
font-style: italic;
}
.my-react-select .Select-value:nth-child(4):not(:nth-last-child(2)) .Select-value-icon,
.my-react-select .Select-value:nth-child(n+5) {
display: none;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.min.js"></script>
<script src="https://unpkg.com/prop-types@15.5.10/prop-types.js"></script>
<script src="https://unpkg.com/classnames@2.2.5/index.js"></script>
<script src="https://unpkg.com/react-input-autosize@2.0.0/dist/react-input-autosize.js"></script>
<script src="https://unpkg.com/react-select@1.3.0/dist/react-select.js"></script>
<link rel="stylesheet" href="https://unpkg.com/react-select@1.3.0/dist/react-select.css">
<div id="root"></div>
关于javascript - 如何使用 react-select 呈现 "N items selected"而不是 N 个选定项目的列表,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/48323716/