1.2

4.v-show指令

作用：v-show指令，根据真假值，切换元素的显示状态

代码实例

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../js/vue.js"></script>
</head>
<body>
    <div id="app" >
        <input type="button" value="切换" @click="change" />
        <img v-show="flag" src="../img/car.gif">
    </div>
</body>
    <script>
        var obj = new Vue({
            el: "#app",
            data: {
                flag: true,
            },
            methods:{
                change:function(){
                    this.flag = !this.flag;
                },
            }
        });
    </script>
</html>

v-show指令总结

原理是修改元素的display属性，实现显示或者隐藏
指令后面导入内容，最终会解析为布尔值
值为true显示，为false则隐藏
数据改变之后，显示的状态会同步更新

5. v-if 指令

作用：根据表达式的真假，切换元素的显示和隐藏（操纵dom元素）

代码实例：

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../js/vue.js"></script>
</head>
<body>
    <div id="app">
        <input type="button" value="切换" v-on:click="changeShow" />
        <img v-if="isShow" src="../img/car.gif"/>
    </div>
</body>
    <script>
        var obj = new Vue({
            el: "#app",
            data: {
                isShow: true,
            },
            methods:{
                changeShow: function(){
                    this.isShow = !this.isShow;
                },
            }
        });
    </script>
</html>