微信小程序现在越来越火爆了，我也看到很多在校大学生都在自学了，那些专门从事APP开发，网页开发的工作者更是看到了小程序的前景，在小程序领域也掺上一脚，本人也是自学小程序的，初期跟很多人一样，遇到一些不懂的想问问别人，到贴吧去，一大堆广告，根本没人帮忙解决问题。
今天教一些刚入门的同学做一款计算器，如果C语言是编程的最佳入门语言，那计算器应该算得上是小程序的入门demo了，希望刚入门的同学们认真品味下面的代码，从wxml到js，再到wxss（页面的布局)，每个代码都要弄懂他的意思
废话不多说，先上效果图，这是我入门时候自己做的一款计算器，很简单，逻辑也很单一，只是我们身边最常见的计算器的逻辑，我觉得从这个demo我更深刻学习到了wxss页面的布局知识
代码附上：
app.json
{ "pages":[ "pages/index/index", "pages/logs/logs" ], "window": { "navigationBarBackgroundColor": "#000000", "navigationBarTextStyle": "white", "navigationBarTitleText": "智能计算器" }, "tabBar": { //补充说一下，我这个tabBar是用来设置底部tab的 "color":"#ff69b4", "selectedColor":"#0000ff", "backgroundColor":"#ffff00", "list": [ { "pagePath": "pages/index/index", "text": "计 算 机" }, { "pagePath": "pages/logs/logs", "text": "日志" }, { "pagePath":"pages/logs/logs", "text":"回家" } ]}}/*app.wxss/*
.container { height: 100%; display: flex; flex-direction: column; align-items: center; justify-content: space-between; padding: 200rpx 0; box-sizing: border-box;} **其中一些组件不认识的话， 建议到微信小程序官网多看几遍
https://developers.weixin.qq.com/miniprogram/dev/framework/config.html**
index.wxml:
template name="calculator-key" button hover-start-time="{{5}}" hover-stay-time="{{100}}" hover-class="calculator-key-hover" data-key="{{className}}" class="calculator-key {{className}}"{{display}}/button/templateview class="calculator" view class="calculator-display" view class="calculator-display-text"{{displayValue}}/view /view view class="calculator-keypad" view class="input-keys" view class="function-keys" catchtap="onTapFunction" template is="calculator-key" data="{{className: 'key-clear', display: clearDisplay ? 'C' : 'C'}}"/ template is="calculator-key" data="{{className: 'key-sign', display: '+/-'}}"/ template is="calculator-key" data="{{className: 'key-percent', display: '%'}}"/ /view view class="digit-keys" catchtap="onTapDigit" template is="calculator-key" data="{{className: 'key-0', display: '0'}}"/ template is="calculator-key" data="{{className: 'key-dot', display: '●'}}"/ template is="calculator-key" data="{{className: 'key-1', display: '1'}}"/ template is="calculator-key" data="{{className: 'key-2', display: '2'}}"/ template is="calculator-key" data="{{className: 'key-3', display: '3'}}"/ template is="calculator-key" data="{{className: 'key-4', display: '4'}}"/ template is="calculator-key" data="{{className: 'key-5', display: '5'}}"/ template is="calculator-key" data="{{className: 'key-6', display: '6'}}"/ template is="calculator-key" data="{{className: 'key-7', display: '7'}}"/ template is="calculator-key" data="{{className: 'key-8', display: '8'}}"/ template is="calculator-key" data="{{className: 'key-9', display: '9'}}"/ /view /view view class="operator-keys" catchtap="onTapOperator" template is="calculator-key" data="{{className: 'key-divide', display: '÷'}}"/ template is="calculator-key" data="{{className: 'key-multiply', display: '×'}}"/ template is="calculator-key" data="{{className: 'key-subtract', display: '−'}}"/ template is="calculator-key" data="{{className: 'key-add', display: '+'}}"/ template is="calculator-key" data="{{className: 'key-equals', display: '='}}"/ /view /view/viewindex.js:
Page({ data: { value: null, // 上次计算后的结果，null表示没有上次计算的结果 displayValue: '0', // 显示数值 operator: null, // 上次计算符号，null表示没有未完成的计算 waitingForOperand: false // 前一按键是否为计算符号 }, onLoad: function (options) { this.calculatorOperations = { 'key-divide': (prevValue, nextValue) = prevValue / nextValue, 'key-multiply': (prevValue, nextValue) = prevValue * nextValue, 'key-add': (prevValue, nextValue) = prevValue + nextValue, 'key-subtract': (prevValue, nextValue) = prevValue - nextValue, 'key-equals': (prevValue, nextValue) = nextValue } }, /* AC操作，一下回到解放前 */ clearAll() { this.setData({ value: null, displayValue: '0', operator: null, waitingForOperand: false }) }, /* 仅清空当前显示的输入值 */ clearDisplay() { this.setData({ displayValue: '0' }) }, onTapFunction: function (event) { const key = event.target.dataset.key; switch (key) { case 'key-clear': if (this.data.displayValue !== '0') { this.clearDisplay(); } else { this.clearAll(); } break; case 'key-sign': var newValue = parseFloat(this.data.displayValue) * -1 this.setData({ displayValue: String(newValue) }) break; case 'key-percent': const fixedDigits = this.data.displayValue.replace(/^-?d*.?/, '') var newValue = parseFloat(this.data.displayValue) / 100 this.setData({ displayValue: String(newValue.toFixed(fixedDigits.length + 2)) }); break; default: break; } }, onTapOperator: function (event) { const nextOperator = event.target.dataset.key; const inputValue = parseFloat(this.data.displayValue); if (this.data.value == null) { this.setData({ value: inputValue }); } else if (this.data.operator) { const currentValue = this.data.value || 0; const newValue = this.calculatorOperations[this.data.operator](currentValue, inputValue); this.setData({ value: newValue, displayValue: String(newValue) }); } this.setData({ waitingForOperand: true, operator: nextOperator }); }, onTapDigit: function (event) { const key = event.target.dataset.key; // 根据data-key标记按键 if (key == 'key-dot') { // 按下点号 if (!(/./).test(this.data.displayValue)) { this.setData({ displayValue: this.data.displayValue + '.', waitingForOperand: false }) } } else { // 按下数字键 const digit = key[key.length - 1]; if (this.data.waitingForOperand) { this.setData({ displayValue: String(digit), waitingForOperand: false }) } else { this.setData({ displayValue: this.data.displayValue === '0' ? String(digit) : this.data.displayValue + digit }) } } }})index.wxss:
page { height:100%;}.calculator { width: 100%; height: 100vh; border:solid 1px; background: rgb(238, 5, 5); position: relative; box-shadow: 0px 0px 20px 0px rgb(211, 41, 41); display: flex; flex-direction: column; box-sizing: border-box;}.calculator-display { /*显示器背景颜色*/ background: #2c2a2c; flex: 1;}/*TODO:解决文本垂直居中问题,显示器数字颜色*/.calculator-display-text { padding: 0 30px; font-size: 3em; color: rgb(245, 245, 248); text-align: right;}.calculator-keypad { display: flex;}.calculator .function-keys { display: flex; color:rgb(245, 13, 13);}.calculator .digit-keys { background: #0808f7; display: flex; flex-direction: row; flex-wrap: wrap-reverse;}.calculator-key-hover { /*按钮按下以后的颜色*/ box-shadow: inset 0px 0px 25vw 0px hsla(71, 90%, 48%, 0.898);}.calculator-key {background-color:aqua; display: block; width: 25vw; height: 25vw; line-height: 25vw; border-top: 1px solid rgb(6, 245, 78); border-right: 1px solid rgb(19, 241, 12); text-align: center; box-sizing: border-box;}.calculator .function-keys .calculator-key { font-size: 2em;}.calculator .digit-keys .calculator-key { font-size: 3em;}.calculator .digit-keys .key-0 {
