JavaScript가 팬 인터페이스를 구현합니다.

function getFansList(userId, pageNum) {
  // 调用接口获取粉丝列表
  const url = `https://example.com/api/getFansList?userId=${userId}&pageNum=${pageNum}`;
  return fetch(url).then(response => response.json());
}

function renderFansList(list) {
  // 获取ul元素
  const ul = document.querySelector('#fansList');
  // 清空ul元素
  ul.innerHTML = '';
  // 遍历粉丝列表，创建li元素并添加到ul元素中
  for (let i = 0; i < list.length; i++) {
    const fan = list[i];
    const li = document.createElement('li');
    li.innerHTML = `
      <img src="${fan.avatar}">
      <div>${fan.nickname}</div>
      <button class="${fan.isFollowing ? 'following' : 'follow'}">${fan.isFollowing ? '已关注' : '关注'}</button>
    `;
    ul.appendChild(li);
  }
}

const input = document.querySelector('#searchInput');
const btnFilter = document.querySelectorAll('.filter-btn');

// 添加搜索功能
function searchFans(keyword, list) {
  const result = list.filter(fan => fan.nickname.includes(keyword));
  renderFansList(result);
}

input.addEventListener('input', function(e) {
  const keyword = e.target.value.trim();
  if (keyword) {
    searchFans(keyword, fansList);
  } else {
    renderFansList(fansList);
  }
});

// 添加过滤功能
function filterFans(status, list) {
  const result = list.filter(fan => {
    if (status === 'all') {
      return true;
    } else if (status === 'following') {
      return fan.isFollowing;
    } else {
      return !fan.isFollowing;
    }
  });
  renderFansList(result);
}

for (let i = 0; i < btnFilter.length; i++) {
  btnFilter[i].addEventListener('click', function(e) {
    const status = e.target.dataset.status;
    filterFans(status, fansList);
  });
}

const btnBatch = document.querySelector('#batchBtn');

// 添加复选框和批量操作功能
function addCheckbox(list) {
  const ul = document.querySelector('#fansList');
  for (let i = 0; i < list.length; i++) {
    const li = ul.children[i];
    const input = document.createElement('input');
    input.type = 'checkbox';
    input.value = i;
    li.insertBefore(input, li.firstChild);
  }
  // 监听“取消关注”按钮的点击事件
  btnBatch.addEventListener('click', function() {
    const inputs = document.querySelectorAll('input[type="checkbox"]');
    for (let i = 0; i < inputs.length; i++) {
      const input = inputs[i];
      if (input.checked) {
        const fan = list[input.value];
        cancelFollowing(fan.id).then(() => {
          fan.isFollowing = false;
          input.checked = false;
          li = input.parentNode;
          li.querySelector('button').className = 'follow';
          li.querySelector('button').textContent = '关注';
        });
      }
    }
  });
}