zhengwu-wechat-applet/pages/home/location/location.js

// pages/home/location/location.js
var city = require('../../../libs/city.js');
const app = getApp();
Page({

  /**
   * 页面的初始数据
   */
  data: {
    city: app.globalData.city,
    cityData: {},//所有城市
    hotCityData: [],//热门城市
    _py: ["hot", "A", "B", "C", "D", "E", "F", "G", "H", "J", "K", "L", "M", "N", "P", "Q", "R", "S", "T", "W", "X", "Y", "Z"],//字母索引
    hidden: true,
    showPy: '★',
  },
  //选择城市
  selectCity: function (e) {
    app.globalData.city = e.currentTarget.dataset.name;
    wx.reLaunch({
      url: '/pages/home/index?city=' + e.currentTarget.dataset.name,
    })
  },
  /**
   * 生命周期函数--监听页面加载
   */
  onLoad: function (options) {
    var that = this;
    that.setData({
      cityData: city.all,
      hotCityData: city.hot
    });
  },

  /**
   * 生命周期函数--监听页面初次渲染完成
   */
  onReady: function () {

  },

  /**
   * 生命周期函数--监听页面显示
   */
  onShow: function () {
    this.setData({
      city: app.globalData.city
    })
  },

  /**
   * 生命周期函数--监听页面隐藏
   */
  onHide: function () {

  },

  /**
   * 生命周期函数--监听页面卸载
   */
  onUnload: function () {

  },

  /**
   * 页面相关事件处理函数--监听用户下拉动作
   */
  onPullDownRefresh: function () {

  },

  /**
   * 页面上拉触底事件的处理函数
   */
  onReachBottom: function () {

  },

  /**
   * 用户点击右上角分享
   */
  onShareAppMessage: function () {

  },
  //获取文字信息
  getPy: function (e) {
    this.setData({
      hidden: false,
      showPy: e.target.id,
    })
  },

  setPy: function (e) {
    this.setData({
      hidden: true,
      scrollTopId:e.target.id
      // scrollTopId: this.data.showPy
    })
  },

  //触发全部开始选择
  tStart: function () {
    this.setData({
      hidden: false
    })
  },

  //滑动选择城市
  tMove: function (e) {
    var y = e.touches[0].clientY;//触摸点Y坐标
    var offsettop = e.currentTarget.offsetTop;//节点Y坐标
    //判断选择区域,只有在选择区才会生效
    if (y > offsettop && y < offsettop+276) {
      var num = parseInt((y - offsettop) / 12);
      this.setData({
        showPy: this.data._py[num]
      })
    };
  },

  //触发结束选择
  tEnd: function () {
    this.setData({
      hidden: true,
      scrollTopId: this.data.showPy
    })
  },

})