How to implement the like function in WeChat mini program

This article mainly introduces the method of WeChat applet to implement the like function based on local cache, involving related implementation techniques such as WeChat applet interface layout, event response and cache operation. Friends in need can refer to the following

This article describes the example of how WeChat applet implements the like function based on local cache. Share it with everyone for your reference, the details are as follows:

Writing in wxml

Note:

1. Use wx:if= "{{condition}}" wx:elseRealize the switching effect of the icon;
2. Bind the click event to the imagebindtap="toCollect", both image tags must be bound !

<image wx:if="{{collection}}" src="/images/icon/pic1.png" bindtap="toCollect"></image>
<image wx:else src="/images/icon/pic2.png" bindtap="toCollect"></image>

Writing in js:

Page({
 data: {
 },
 onLoad: function(option) {
  // 获取接收到的id值
  var getId = option.id;
  // 让接收到的id值传递到data:{}里面
  this.setData({
   currentId: getId
  });
  // 读取所有的文章列表点赞缓存状态
  var cache = wx.getStorageSync('cache_key');
  // 如果缓存状态存在
  if (cache) {
   // 拿到所有缓存状态中的1个
   var currentCache = cache[getId];
   // 把拿到的缓存状态中的1个赋值给data中的collection，如果当前文章没有缓存状态，currentCache 的值就是 false，如果当前文章的缓存存在，那么 currentCache 就是有值的，有值的说明 currentCache 的值是 true
   this.setData({
    collection: currentCache
   })
  } else {
   // 如果所有的缓存状态都不存在 就让不存在的缓存存在
   var cache = {};
   // 既然所有的缓存都不存在，那么当前这个文章点赞的缓存也不存在，我们可以把当前这个文章点赞的缓存值设置为 false
   cache[getId] = false;
   // 把设置的当前文章点赞放在整体的缓存中
   wx.setStorageSync('cache_key',cache);
  }
 },
 // 点击图片的点赞事件 这里使用的是同步的方式
 toCollect: function(event) {
  // 获取所有的缓存
  var cache = wx.getStorageSync('cache_key');
  // 获取当前文章是否被点赞的缓存
  var currentCache = cache[this.data.currentId];
  // 取反，点赞的变成未点赞 未点赞的变成点赞
  currentCache = !currentCache;
  // 更新cache中的对应的1个的缓存值，使其等于当前取反的缓存值
  cache[this.data.currentId] = currentCache;
  // 重新设置缓存
  wx.setStorageSync('cache_key',cache);
  // 更新数据绑定,从而切换图片
  this.setData({
   // collection 默认的是 false
   collection: currentCache
  });
  // 交互反馈
  wx.showToast({
   title: currentCache?'点赞':'取消',
   icon: 'success',
   duration: 2000
  });
 }
})

Operation feedback in js—Writing of wx.showModal:

// 点击图片的点赞事件 这里使用的是同步的方式
toCollect: function(event) {
  // 获取缓存，得到当前文章是否被点赞
  var cache = wx.getStorageSync('cache_key');
  // 获取当前文章是否被点赞的缓存
  var currentCache = cache[this.data.currentId];
  // 取反，点赞的变成未点赞 未点赞的变成点赞
  currentCache = !currentCache;
  // 更新cache中的对应的1个的缓存值，使其等于当前取反的缓存值
  cache[this.data.currentId] = currentCache;
  // 调用 showModal方法
  this.showModal(cache,currentCache);
}，
showModal: function(cache,currentCache) {
 var that = this;
 wx.showModal({
  title: "点赞"
  content: currentCache?"要点赞吗？":"要取消赞吗？",
  showCancel: "true",
  cancelText: "取消",
  cancelColor: "#666",
  confirmText: "确定",
  confirmColor: "#222",
  success: function(res) {
   if (res.confirm) {
    // 重新设置缓存
    wx.setStorageSync('cache_key',cache);
    // 更新数据绑定,从而切换图片
    that.setData({
     collection: currentCache
    })
   }
  }
 })
}

Above I compiled it for everyone. I hope it will be helpful to everyone in the future.

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