Question

我正在处理React.js分页，每当我按特定数字时，我想设置一个活动类。

如何在下面的代码中添加它：

function Pagination() {
    const [page, setPage] = useState(1);
  
    const goPreviousPage = () => {
      if (page > 1) {
        setPage(prevPage => prevPage - 1);
      }
    };
  
    const goNextPage = () => {
      if (page < 11) {
        setPage(prevPage => prevPage + 1);
      }
    };
  
    const goSpecificPage = page => {
      setPage(page);
    };
  
    return (
      <div className="pagination-wrapper">
        <button onClick={goPreviousPage} disabled={page <= 1}>
          Previous Page
        </button>
        <button className="" onClick={() => goSpecificPage(page)}>{page}</button>
        <button onClick={() => goSpecificPage(page + 1)}>{page + 1}</button>
        <button onClick={() => goSpecificPage(page + 2)}>{page + 2}</button>
        <button onClick={goNextPage} disabled={page >= 10 }>
          Next Page
        </button>
      </div>
    );
  }

非常感谢！

Answer 1

您需要跟踪状态中当前活动的按钮并有条件地分配className：

const { useState } = React,
      { render } = ReactDOM,
      rootNode = document.getElementById('root')
      
const PaginationButtons = () => {
  const [activeButton, setActiveButton] = useState(1),
        handleButtonClick = buttonIdx => {
          setActiveButton(buttonIdx)
          // do whatever you need upon button click
        }
  return (
    <div>
    <button onClick={() => handleButtonClick(0)}>Prev</button>
    <button 
      onClick={() => handleButtonClick(1)}
      className={activeButton == 1 ? 'active' : ''}
    >
      1
    </button>
    <button 
      onClick={() => handleButtonClick(2)} 
      className={activeButton == 2 ? 'active' : ''}
    >
      2
    </button>
    <button 
      onClick={() => handleButtonClick(3)}
      className={activeButton == 3 ? 'active' : ''}
    >
      3
    </button>
    <button onClick={() => handleButtonClick(4)}>Next</button>
    </div>
  )
}      

render (
  <PaginationButtons />,
  rootNode
)

.active {
  background-color: orange;
  color: #fff;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.12.0/umd/react.production.min.js"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.11.0/umd/react-dom.production.min.js"></script><div id="root"></div>

将活动班级分配给单击的按钮

1 个答案: