核心代码

bull() {
                    if (this.show) {
                        this.show = false
                    } else {
                        this.show = true
                    }
                }

演示代码

<script src="https://unpkg.com/vue@next"></script>
<div id="Application">
        <h1 v-if="show">title</h1>
        <p v-else>如果不显示标题就显示段落</p>
        <button @click="bull">点击切换show布尔属性</button>
    </div>


    <script>
        const App = {
            data() {
                return {
                    show: true,
                }
            },

            methods: {
                bull() {
                    if (this.show) {
                        this.show = false
                    } else {
                        this.show = true
                    }
                }
            }
        }
        Vue.createApp(App).mount("#Application")

    </script>

Demo