vue动态绑定属性--基本用法及动态绑定class

动态绑定属性v-bind:，语法糖形式:省略v-bind，仅写一个冒号。

一、动态绑定基本属性

 1 <body>
 2   <!-- v-bind 动态绑定属性-基本用法 -->
 3   <img v-bind:src="imgUrl" alt="">
 4   <script src="../js/vue.js"></script>
 5  　　<script>
 6      　setTimeout(function() {
 7        　const vm = new Vue({
 8          el: '#app',
 9          data: {
10            imgUrl: 'https://gimg2.baidu.com/image_search/src=http%3A%2F%2Fimg.jj20.com%2Fup%2Fallimg%2F4k%2Fs%2F02%2F2109242332225H9-0-lp.jpg&refer=http%3A%2F%2Fimg.jj20.com&app=2002&size=f9999,10000&q=a80&n=0&g=0n&fmt=auto?sec=1650099133&t=7737c14262a80534f32b81b3210ae247',
11          },
12        });
13      },2000);
14    </script>
15 </body>

二、动态绑定class

（1）基本用法：

 1 <head>
 2   <style>
 3     .active{
 4       color: red;
 5     }
 6   </style>
 7 </head>
 8 
 9 <body>
10   <div id="app">
11 
12     <!-- v-bind动态绑定class--基本用法 -->
13     <div class="active">{{msg}}</div>
14     <div :class="on">{{msg}}</div>
15 
16   </div>
17   <script src="../js/vue.js"></script>
18   <script>
19     setTimeout(function() {
20       const vm = new Vue({
21         el: '#app',
22         data: {
23           msg: 'hello',
24           on: 'active',
25         }
26       });
27     },2000);
28   </script>
29 </body>

（2）对象语法：

　　a.语法格式：v-bind:class="{类名1:布尔值,类名2:布尔值}"

 1 <head>
 2   <style>
 3     .active{
 4       color: red;
 5     }
 6   </style>
 7 </head>
 8 
 9 <body>
10   <div id="app">
11 
12     <!-- v-bind动态绑定class--对象语法(使用较多) -->
13     <div :class="{active:isActive,line:isLine}">{{msg}}</div>
14 
15   </div>
16   <script src="../js/vue.js"></script>
17   <script>
18     setTimeout(function() {
19       const vm = new Vue({
20         el: '#app',
21         data: {
22           msg: 'hello',
23           isActive: false,
24           isLine: true,
25         }
26       });
27     },2000);
28   </script>
29 </body>
30

　　b.如果绑定的对象太长，可以放在方法或者是计算属性中，将其返回，调用方法时必须加上括号

 1 <head>
 2   <style>
 3     .active{
 4       color: red;
 5     }
 6   </style>
 7 </head>
 8 
 9 <body>
10   <div id="app">
11 
12     <div :class="getClassesObj()">{{msg}}</div>
13  
14   </div>
15   <script src="../js/vue.js"></script>
16   <script>
17     setTimeout(function() {
18       const vm = new Vue({
19         el: '#app',
20         data: {
21           isActive: false,
22           isLine: true
23         },
24         methods: {
25           getClassesObj(){
26             return {active: this.isActive, line:this.isLine};
27           }
28         }
29       });
30     },2000);
31   </script>
32 </body>

（3）数组语法

 1 <head>
 2   <style>
 3     .active{
 4       color: red;
 5     }
 6   </style>
 7 </head>
 8 
 9 <body>
10   <div id="app">
11 
12     <!-- v-bind动态绑定class--数组语法(少) -->
13     <h1 :class="['active', 'line']"></h1>
14     <h1 :class="[active, line]">v-bind动态绑定class--数组语法(少)</h1>
15     <h1 :class="getClassesArr()">v-bind动态绑定class--数组语法(少)-方法</h1>
16    
17   </div>
18   <script src="../js/vue.js"></script>
19   <script>
20     setTimeout(function() {
21       const vm = new Vue({
22         el: '#app',
23         data: {
24           msg: 'hello',
25           active: 'aaa',
26           line: 'bbb',
27         },
28         methods: {
29           getClassesArr(){
30             return [this.active, this.line];
31           }
32         },
33       });
34     },2000);
35   </script>
36 </body>
37 
38 </html>