详解mpvue scroll-view自动回弹bug解决方案

表现

设置了scroll-top的scroll-view组件，在组件所在vue实例data发生改变时会自动回弹到最上方

解决方案

打开 node_modules/mpvue/index.js, 在任意位置添加以下两个方法

function calcdiff(holder, key, newobj, oldobj) {
 if (newobj === oldobj || newobj === undefined) {
  return
 }

 if (newobj == null || oldobj == null || typeof newobj !== typeof oldobj) {
  holder[key] = newobj
 } else if (array.isarray(newobj) && array.isarray(oldobj)) {
  if (newobj.length === oldobj.length) {
   for (var i = 0, len = newobj.length; i < len; ++i) {
    calcdiff(holder, key + '[' + i + ']', newobj[i], oldobj[i])
   }
  } else {
   holder[key] = newobj
  }
 } else if (typeof newobj === 'object' && typeof oldobj === 'object') {
  var newkeys = object.keys(newobj)
  var oldkeys = object.keys(oldobj)

  if (newkeys.length !== oldkeys.length) {
   holder[key] = newobj
  } else {
   var allkeysset = object.create(null)
   for (var i = 0, len = newkeys.length; i < len; ++i) {
    allkeysset[newkeys[i]] = true
    allkeysset[oldkeys[i]] = true
   }
   if (object.keys(allkeysset).length !== newkeys.length) {
    holder[key] = newobj
   } else {
    for (var i = 0, len = newkeys.length; i < len; ++i) {
     var k = newkeys[i]
     calcdiff(holder, key + '.' + k, newobj[k], oldobj[k])
    }
   }
  }
 } else if (newobj !== oldobj) {
  holder[key] = newobj
 }
}

function diff(newobj, oldobj) {
 var keys = object.keys(newobj)
 var diffresult = {}
 for (var i = 0, len = keys.length; i < len; ++i) {
  var k = keys[i]
  var oldkeypath = k.split('.')
  var oldvalue = oldobj[oldkeypath[0]]
  for (var j = 1, jlen = oldkeypath.length; j < jlen && oldvalue !== undefined; ++j) {
   oldvalue = oldvalue[oldkeypath[j]]
  }
  calcdiff(diffresult, k, newobj[k], oldvalue)
 }
 return diffresult
} 

2.找到 throttlesetdata 修改为

var throttlesetdata = throttle(function (page, data) {
 page.setdata(diff(data, page.data));
}, 50); 

3.找到 updatedatatomp 方法, 将 throttlesetdata 的调用方式改为

throttlesetdata(page, data);

希望官方早日修复，参考：

使用脏检查优化每次更新数据时都会传输大量数据的问题, 解决删除回退, 列表忽然滚动到顶部等问题

 以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。