<switch bindchange="switchChange" color ="#F39C89" class="switch"/>

Page({
 data: {
 skinStyle: ""
 },
 onLoad: function (options) {
 },
 switchChange:function(e){
 var that =this
 var style
 //如果开启
 if(e.detail.value == true){
  style="dark"
 }else{
  //否则
  style.skin = ""
 }
 //保存信息
 that.setData({
  skinStyle: style
 })
 }
})

/*夜间模式*/
/****个人信息页面****/
.dark-box{
 background: #000 !important;
}
/*用户信息部分*/
.dark-box .user-box{
 background: #333 !important;
 color: #999;
}
/*列表部分*/
.dark-box .extra-box{
 background: #333 !important;
}
.dark-box .extra-box .extra-item{
 border-bottom: 1px solid #000 !important;
}
.dark-box .extra-box .item-head{
 color: #999;
}
.dark-box .between-box{
 background: #333 !important;
}
.dark-box .between-left{
 background: #333 !important;
}
.dark-box .between-left .item-head{
 color: #999;
}
/****个人信息页面结束****/

<view class="my-box {{skinStyle}}-box">

@import "../../skin/dark.wxss";

var app=getApp()
Page({
 data: {
 skinStyle: ""
 },
 onLoad: function (options) {
 },
 switchChange:function(e){
 var that =this
 //设置全局变量
 if(e.detail.value == true){
  app.globalData.skin="dark"
 }else{
  app.globalData.skin = ""
 }
 that.setData({
  skinStyle: app.globalData.skin
 })
 }
})

var app=getApp()
Page({
 data: {
 skinStyle: ""
 },
 onLoad: function (options) {

 },
 switchChange:function(e){
 var that =this

 //设置全局变量
 if(e.detail.value == true){
  app.globalData.skin="dark"
 }else{
  app.globalData.skin = ""
 }
 that.setData({
  skinStyle: app.globalData.skin
 })
 //保存到本地
 wx.setStorage({
  key: "skin",
  data: app.globalData.skin
 })
 }
})

 getSkin:function(){
 var that =this
 wx.getStorage({
  key: 'skin',
  success: function (res) {
  that.globalData.skin=res.data
  }
 })
 }

 onLoad: function (options) {
  var that =this 
  that.setData({
  skinStyle: app.globalData.skin
  })
 }