Vue.js 双向数据绑定

r囧r小猫 2022-03-18 02:52 349阅读 0赞

### 文章目录 ###

*   *  Vue指令之\`v-model\`和\`双向数据绑定\`
     *  简易计算器
     *  源代码

## Vue指令之`v-model`和`双向数据绑定` ##

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70]

## 简易计算器 ##

<!DOCTYPE html>
    <html lang="en">
    
    <head>
      <meta charset="UTF-8">
      <meta name="viewport" content="width=device-width, initial-scale=1.0">
      <meta http-equiv="X-UA-Compatible" content="ie=edge">
      <title>Document</title>
      <script src="./lib/vue-2.4.0.js"></script>
    </head>
    
    <body>
      <div id="app">
        <input type="text" v-model="n1">
    
        <select v-model="opt">
          <option value="+">+</option>
          <option value="-">-</option>
          <option value="*">*</option>
          <option value="/">/</option>
        </select>
    
        <input type="text" v-model="n2">
    
        <input type="button" value="=" @click="calc">
    
        <input type="text" v-model="result">
      </div>
    
      <script>
        // 创建 Vue 实例，得到 ViewModel
        var vm = new Vue({
          el: '#app',
          data: {
            n1: 0,
            n2: 0,
            result: 0,
            opt: '+'
          },
          methods: {
            calc() { // 计算器算数的方法  
              // 逻辑：
              /* switch (this.opt) {
                case '+':
                  this.result = parseInt(this.n1) + parseInt(this.n2)
                  break;
                case '-':
                  this.result = parseInt(this.n1) - parseInt(this.n2)
                  break;
                case '*':
                  this.result = parseInt(this.n1) * parseInt(this.n2)
                  break;
                case '/':
                  this.result = parseInt(this.n1) / parseInt(this.n2)
                  break;
              } */
    
              // 注意：这是投机取巧的方式，正式开发中，尽量少用
              var codeStr = 'parseInt(this.n1) ' + this.opt + ' parseInt(this.n2)'
              this.result = eval(codeStr)
            }
          }
        });
      </script>
    </body>
    
    </html>

![在这里插入图片描述][2019021822221450.png]

## 源代码 ##

[查看][Link 1]

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nja2V2aW5jeWg_size_16_color_FFFFFF_t_70]: /images/20220318/984a06622de64360894516241e9ba390.png
[2019021822221450.png]: /images/20220318/914e575921e84bbe8c416bd9496df3b2.png
[Link 1]: https://gitee.com/cckevincyh/VueDemo/tree/master/day01