vue.js $set的使用 数组

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<!DOCTYPE html>  
<html lang="en">  
  
<head>  
    <meta charset="UTF-8">  
    <title>Document</title>  
    <script src="vue.js"></script>  
    <style>  
    .blue {  
        color: blue;  
    }  
    </style>  
</head>  
  
<body>  
    <div id="example-1">  
        <ul>  
            <template v-for="item in items">  
                <li>  
                    {{$index}}.{{ item.msg }}  
  
                    <button v-on:click="f5(item)">vm.items.splice(index, 1)</button>  
  
                    <button v-on:click="f6(item)">vm.remove</button>  
                </li>  
            </template>  
        </ul>  
  
          
        <ul>  
            <li>  
                <button v-on:click="f1">vm.items[0] = {} 失效</button>  
            </li>  
            <li>  
                <button v-on:click="f2">vm.items.$set(0, { childMsg: 'Changed!'}) </button>  
            </li>  
            <li>  
                <button v-on:click="f3">vm.items.length = 0 失效</button>  
            </li>  
            <li>  
                <button v-on:click="f4">vm.items={}</button>  
            </li>  
        </ul>  
        <div class="blue">  
            {{$data | json }}  
        </div>  
        <pre>  
        因为 JavaScript 的限制,Vue.js 不能检测到下面数组变化:  
        直接用索引设置元素,如 vm.items[0] = {};  
        修改数据的长度,如 vm.items.length = 0</pre>  
    </div>  
    <script>  
    var vm = new Vue({  
        el: '#example-1',  
        data: {  
            items: [{  
                msg: 'Foo'  
            }, {  
                msg: 'Bar'  
            }, {  
                msg: 'George'  
            }]  
        },  
        methods: {  
            f1: function() {  
                vm.items[0] = {}; // 失效  
            },  
            f2: function() {  
                vm.items.$set(0, {  
                    childMsg: 'Changed!'  
                })  
                  
                 vm.items.$set(2, {  
                    msg: 'dongtao!'  
                })  
            },  
            f3: function() {  
                vm.items.length = 0; // 失效  
            },  
            f4: function() {  
                vm.items = {}  
            },  
            f5: function(item) {  
                var index = this.items.indexOf(item) //Search an array for the item  
                if (index !== -1) {  
                    this.items.splice(index, 1) //Selects a part of an array, and returns the new array  
                }  
            },  
            f6: function(item) {  
                this.items.$remove(item)  
            }  
        }  
  
    })  
    </script>  
</body>  
  
</html>  
原文地址:https://www.cnblogs.com/lsy0403/p/8780709.html