vue项目中限制input只能输入一个小数点及后两位number

我这里用的是vue移动端的vant框架中的NumberKeyboard 数字键盘组件

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如下图这种效果 ↓

image.png

1.安装vue脚手架

推荐使用 Vue 官方提供的脚手架 Vue Cli 3 创建项目
npm install -g @vue/cli

2.创建一个项目

vue create hello-world

3.安装 vant

npm 安装
npm i vant -S
** yarn 安装**
yarn add vant

4.引入组件

使用 babel-plugin-import (推荐)

babel-plugin-import 是一款 babel 插件，它会在编译过程中将 import 的写法自动转换为按需引入的方式
安装 babel-plugin-import 插件
npm i babel-plugin-import -D

image.png

// .babelrc 中配置
// 注意：webpack 1 无需设置 libraryDirectory
{
  "plugins": [
    ["import", {
      "libraryName": "vant",
      "libraryDirectory": "es",
      "style": true
    }]
  ]
}

5.引用组件，实现效果图

<template>
  <!-- 抽奖奖金提现页面 -->
  <div class="withDrawals-wrapper">
    <!-- 选择银行卡 -->
    <div class="bank-wrapper">
      <div class="logo"></div>
      <div class="content">
        <div class="name">中国建设银行</div>
        <div class="number">尾号8015储蓄卡</div>
      </div>
    </div>
    <!-- 输入提现金额 -->
    <div class="amount-wrapper">
      <div class="amount-title">提现金额</div>
      <div class="amount-count">
        <span class="yuan">￥</span>
        <van-field
          class="count"
          onfocus="this.blur()"
          v-model="withDrawalsAmount"
          placeholder="请输入提现金额"
        />
      </div>
      <div class="balance-wrapper">
        <span
          class="balance"
        >可用余额{{balance}}元</span>
        <span
          class="all-btn"
        >全部提现</span>
      </div>
      <van-button
        type="primary"
        :disabled="isHasInputValue"
        size="large"
        style="background-color: #128ee8; border-color: #128ee8;"
      >预计两小时内到账,确认提现</van-button>
    </div>
    <!-- 输入键盘 -->
    <van-number-keyboard
      :show="isShowKeyBoard"
      theme="custom"
      extra-key="."
      close-button-text="完成"
      @blur="show = false"
      @input="onClickInputKeyBoard"
      @delete="onDeleteKeyBoard"
    />
  </div>
</template>

// 按需引用组件
import { NumberKeyboard } from 'vant';
Vue.use(NumberKeyboard);
export default {
  data() {
    return {
      isShowKeyBoard: true, // 是否显示虚拟键盘
      withDrawalsAmount: '', // 提现金额
      balance: '0.03' // 可用余额
    }
  },
  methods: {
    /**
     * 模拟键盘点击数字时触发的函数
     */
    onClickInputKeyBoard (value) {
      this.withDrawalsAmount += value
      // 限制只能输入一个小数点及两位小数
      this.withDrawalsAmount = this.withDrawalsAmount.toString().match(/^\d*(\.?\d{0,2})/g)[0] || null
    },
    /**
     * 模拟键盘删除时触发的函数
     */
    onDeleteKeyBoard () {
      let flag = true
      if (flag) {
        // 删除掉字符串最后一个
        this.withDrawalsAmount = this.withDrawalsAmount.substring(0, this.withDrawalsAmount.length - 1)
        if (this.withDrawalsAmount.length === 0) {
          flag = false
          return false
        }
      }
    }
  }
}

// 用的是scss
.withDrawals-wrapper{
  height: 100%;
  font-size: 0.16rem;
  // 选择银行卡
  .bank-wrapper{
    display: flex;
    padding: 0.1rem;
    margin-bottom: 0.1rem;
    background-color: #fff;
    box-shadow: 0px 0px 1px 0px rgba(51, 51, 51, 0.14);
    .logo{
      height: 0.4rem;
      width: 0.4rem;
      flex-shrink: 0;
      background-color: #999;
    }
    .content{
      flex: 1;
      display: flex;
      flex-direction: column;
      justify-content: space-between;
      padding-left: 0.1rem;
      position: relative;
      &::after{
        content: '';
        display: block;
        width: 0.06rem;
        height: 0.06rem;
        border-top: 1px solid rgb(195, 195, 195);
        border-right: 1px solid rgb(195, 195, 195);
        position: absolute;
        top: 50%;
        margin-top: -0.03rem;
        right: 0.1rem;
        transform: rotate(45deg);
      }
      .name{
        font-size: 0.16rem;
      }
      .number{
        font-size: 0.14rem;
        color: #808080;
      }
    }
  }
  // 输入提现金额
  .amount-wrapper{
    padding: 0.14rem 0.1rem;
    background-color: #fff;
    .amount-title{
      color: #333;
    }
    .amount-count{
      display: flex;
      align-items: center;
      padding: 0.2rem 0;
      .yuan{
        width: 0.5rem;
        text-align: center;
        font-size: 0.3rem;
      }
      // .count{}
    }
    .balance-wrapper{
      display: flex;
      justify-content: space-between;
      padding: 0.1rem 0;
      margin-bottom: 0.3rem;
      font-size: 0.14rem;
      .balance{
        color: #808080;
      }
      .active{
        color: #f80000;
      }
      .all-btn{
        color: rgb(52, 152, 214);
      }
    }
  }
}

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记载下，方便自己以后重新回顾。