微信小程序开发之城市选择器 城市切换

移动开发中城市选择器必不可少. 

空白造了个. 

gif: 



这里只上部分js代码:

var city = require('../../utils/city.js');

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//CSDN微信小程序开发专栏:http://blog.csdn.net/column/details/13721.html
Page({
data: {
searchLetter: [],
showLetter: "",
winHeight: 0,
tHeight: 0,
bHeight: 0,
startPageY: 0,
cityList: [],
isShowLetter: false,
scrollTop: 0,
city: ""
},
onLoad: function (options) {
// 生命周期函数--监听页面加载
var searchLetter = city.searchLetter;
var cityList = city.cityList();
// console.log(cityInfo);

var sysInfo = wx.getSystemInfoSync();
console.log(sysInfo);
var winHeight = sysInfo.windowHeight;

//添加要匹配的字母范围值
//1、更加屏幕高度设置子元素的高度
var itemH = winHeight / searchLetter.length;
var tempObj = [];
for (var i = 0; i < searchLetter.length; i++) {
var temp = {};
temp.name = searchLetter[i];
temp.tHeight = i * itemH;
temp.bHeight = (i + 1) * itemH;

tempObj.push(temp)
}

this.setData({
winHeight: winHeight,
itemH: itemH,
searchLetter: tempObj,
cityList: cityList
})

console.log(this.data.cityInfo);
},
onReady: function () {
// 生命周期函数--监听页面初次渲染完成

},
onShow: function () {
// 生命周期函数--监听页面显示

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

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

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

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

},
onShareAppMessage: function () {
// 用户点击右上角分享
return {
title: 'title', // 分享标题
desc: 'desc', // 分享描述
path: 'path' // 分享路径
}
},
searchStart: function (e) {
var showLetter = e.currentTarget.dataset.letter;
var pageY = e.touches[0].pageY;
this.setScrollTop(this, showLetter);
this.nowLetter(pageY, this);
this.setData({
showLetter: showLetter,
startPageY: pageY,
isShowLetter: true,
})
},
searchMove: function (e) {
var pageY = e.touches[0].pageY;
var startPageY = this.data.startPageY;
var tHeight = this.data.tHeight;
var bHeight = this.data.bHeight;
var showLetter = 0;
console.log(pageY);
if (startPageY - pageY > 0) { //向上移动
if (pageY < tHeight) {
// showLetter=this.mateLetter(pageY,this);
this.nowLetter(pageY, this);
}
} else {//向下移动
if (pageY > bHeight) {
// showLetter=this.mateLetter(pageY,this);
this.nowLetter(pageY, this);
}
}
},
searchEnd: function (e) {
// console.log(e);
// var showLetter=e.currentTarget.dataset.letter;
var that = this;
setTimeout(function () {
that.setData({
isShowLetter: false
})
}, 1000)

},
nowLetter: function (pageY, that) {//当前选中的信息
var letterData = this.data.searchLetter;
var bHeight = 0;
var tHeight = 0;
var showLetter = "";
for (var i = 0; i < letterData.length; i++) {
if (letterData[i].tHeight <= pageY && pageY <= letterData[i].bHeight) {
bHeight = letterData[i].bHeight;
tHeight = letterData[i].tHeight;
showLetter = letterData[i].name;
break;
}
}

this.setScrollTop(that, showLetter);

that.setData({
bHeight: bHeight,
tHeight: tHeight,
showLetter: showLetter,
startPageY: pageY
})
},
bindScroll: function (e) {
console.log(e.detail)
},
setScrollTop: function (that, showLetter) {
var scrollTop = 0;
var cityList = that.data.cityList;
var cityCount = 0;
var initialCount = 0;
for (var i = 0; i < cityList.length; i++) {
if (showLetter == cityList[i].initial) {
scrollTop = initialCount * 30 + cityCount * 41;
break;
} else {
initialCount++;
cityCount += cityList[i].cityInfo.length;
}
}

that.setData({
scrollTop: scrollTop
})
},
bindCity: function (e) {
var city = e.currentTarget.dataset.city;
this.setData({ city: city })
}
})

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demo代码下载 
原文地址 
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