我有一个React组件,在组件的渲染方法中,我有这样的东西:

render() {
    return (
        <div>
            <div>
                // removed for brevity
            </div>

           { switch(...) {} }

            <div>
                // removed for brevity
            </div>
        </div>
    );
}

Now the point is that I have two div elements, one at the top and one at the bottom, that are fixed. In the middle I want to have a switch statement, and according to a value in my state I want to render a different component. So basically, I want the two div elements to be fixed always, and just in the middle to render a different component each time. I'm using this to implement a multi-step payment procedure). Though, as is the code currently it doesn't work, as it gives me an error saying that switch is unexpected. Any ideas how to achieve what I want?


当前回答

这是另一种方法。

render() {
   return {this[`renderStep${this.state.step}`]()}

renderStep0() { return 'step 0' }
renderStep1() { return 'step 1' }

其他回答

与其他答案相比,我更倾向于在渲染函数中内联“开关”。它使什么组件可以在那个位置呈现更清楚。你可以使用一个简单的javascript对象来实现一个类似switch的表达式:

render () {
  return (
    <div>
      <div>
        {/* removed for brevity */}
      </div>
      {
        {
          'foo': <Foo />,
          'bar': <Bar />
        }[param]
      }
      <div>
        {/* removed for brevity */}
      </div>
    </div>
  )
}

我们可以直接使用useCallback来做到这一点

const renderContent = useCallback(() => { switch (sortState) { “一”: 返回“一”; “两个”: 返回“两个”; “三”: 返回“三”; “四”: 返回“四”; 默认值: 返回“一”; } }, [sortState]);

这将在jsx中使用

<div>排序:{renderContent()}</div>

如何:

mySwitchFunction = (param) => {
   switch (param) {
      case 'A':
         return ([
            <div />,
         ]);
      // etc...
   }
}
render() {
    return (
       <div>
          <div>
               // removed for brevity
          </div>

          { this.mySwitchFunction(param) }

          <div>
              // removed for brevity
          </div>
      </div>
   );
}

React组件中的Switch-Case语句可以如下使用:

<div  id="time-list">
{   
    (() => {
        switch (groupByFilterId) {
            case 0:/*Case 0 */
                return (
                    <div>Case 0</div>
                )
               break;
           case 1: /*Case 1 */
           return ( 
            <div>Case 1</div>
            )
            break;
           case 2:/*Case 2 */
           return ( 
            <div>Case 2</div>
            )
            break;
        }
     })()}

      
       
    
    </div>

这是另一种方法。

render() {
   return {this[`renderStep${this.state.step}`]()}

renderStep0() { return 'step 0' }
renderStep1() { return 'step 1' }