js加载中的动画

<div id="loading" class="loading">
  <div class="spinner"></div>
</div>

.loading {
  display: none; /* 默认隐藏 */
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.8);
  justify-content: center;
  align-items: center;
  z-index: 9999;
}

.spinner {
  border: 4px solid #f3f3f3;
  border-top: 4px solid #3498db;
  border-radius: 50%;
  width: 50px;
  height: 50px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

function showLoading() {
  document.getElementById('loading').style.display = 'flex';
}

function hideLoading() {
  document.getElementById('loading').style.display = 'none';
}

// 示例：在AJAX请求时显示和隐藏加载动画
document.getElementById('myButton').addEventListener('click', function() {
  showLoading();
  fetch('https://api.example.com/data')
    .then(response => response.json())
    .then(data => {
      // 处理数据
    })
    .catch(error => {
      console.error('Error:', error);
    })
    .finally(() => {
      hideLoading();
    });
});