微信小程序开发之map地图组件定位并手动修改位置偏差

//app.js
App({
 onLaunch: function () {
  //调用API从本地缓存中获取数据
  var logs = wx.getStorageSync('logs') || []
  logs.unshift(Date.now())
  wx.setStorageSync('logs', logs)
 }
 ,getUserInfo:function(cb){
  var that = this
  if(this.globalData.userInfo){
   typeof cb == "function" && cb(this.globalData.userInfo)
  }else{
   //调用登录接口
   wx.login({
    success: function () {
     wx.getUserInfo({
      success: function (res) {
       that.globalData.userInfo = res.userInfo
       typeof cb == "function" && cb(that.globalData.userInfo)
      }
     })
    }
   })
  }
 }
 //get locationInfo
 ,getLocationInfo: function(cb){
  var that = this;
  if(this.globalData.locationInfo){
    cb(this.globalData.locationInfo)
  }else{
    wx.getLocation({
     type: 'gcj02', // 默认为 wgs84 返回 gps 坐标，gcj02 返回可用于 wx.openLocation 的坐标
     success: function(res){
      that.globalData.locationInfo = res;
      cb(that.globalData.locationInfo)
     },
     fail: function() {
      // fail
     },
     complete: function() {
      // complete
     }
    })
  }
 }

 ,globalData:{
  userInfo:null
  ,locationInfo: null
 }
})

<map id="map4select"
 longitude="{{longitude}}" latitude="{{latitude}}" 
 markers="{{markers}}"
 scale="20" 
 style="width:{{map_width}}px;height:{{map_height}}px"
 bindregionchange="regionchange"
 controls="{{controls}}">
</map>

var app = getApp()

Page({
  data:{
   map_width: 380
   ,map_height: 380
  }
  //show current position
  ,onLoad: function(){
  var that = this;
  // 获取定位，并把位置标示出来
  app.getLocationInfo(function(locationInfo){
    console.log('map',locationInfo);
    that.setData({
     longitude: locationInfo.longitude
     ,latitude: locationInfo.latitude
     ,markers:[
      {
      id: 0
      ,iconPath: "../../imgs/ic_position.png"
      ,longitude: locationInfo.longitude
      ,latitude: locationInfo.latitude
      ,width: 30
      ,height: 30
      }
     ]
    })
  })

  //set the width and height
  // 动态设置map的宽和高
  wx.getSystemInfo({
   success: function(res) {
    console.log('getSystemInfo');
    console.log(res.windowWidth);
    that.setData({
      map_width: res.windowWidth
     ,map_height: res.windowWidth
     ,controls: [{
      id: 1,
      iconPath: '../../imgs/ic_location.png',
      position: {
       left: res.windowWidth/2 - 8,
       top: res.windowWidth/2 - 16,
       width: 30,
       height: 30
      },
      clickable: true
     }]
    })
   }
  })

 }
 //获取中间点的经纬度，并mark出来
 ,getLngLat: function(){
   var that = this;
   this.mapCtx = wx.createMapContext("map4select");
   this.mapCtx.getCenterLocation({
    success: function(res){

      that.setData({
      longitude: res.longitude
      ,latitude: res.latitude
      ,markers:[
       {
       id: 0
       ,iconPath: "../../imgs/ic_position.png"
       ,longitude: res.longitude
       ,latitude: res.latitude
       ,width: 30
       ,height: 30
       }
      ]
     })

    }
   })
 }
 ,regionchange(e) {
  // 地图发生变化的时候，获取中间点，也就是用户选择的位置
   if(e.type == 'end'){
     this.getLngLat()
   }
 }
 ,markertap(e) {
  console.log(e)
 }
})