yesen
/
vue-sgg


			
				
					
						
						
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							<!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" />
    <link rel="icon" href="../../logo.svg" />
    <title>天气案例_监视属性</title>
  </head>
  <body>
    <div id="root">
      <h2>今天天气很{{info}}</h2>
      <button @click="isHot = !isHot">切换天气</button>
    </div>

    <script src="../../vue.js"></script>
    <script>
      Vue.config.productionTip = false; // 阻止 vue 在启动时生成生产提示。

      const vm = new Vue({
        el: "#root",
        data: {
          isHot: true,
        },
        methods: {
          //   changeWeather() {
          //     this.isHot = !this.isHot;
          //   },
        },
        computed: {
          info() {
            return this.isHot ? "炎热" : "凉爽";
          },
        },
        // watch: {
        //   isHot: {
        //     immediate: true, // 初始化时让 handler 调用一下
        //     handler(currentValue, prevValue) {
        //       console.log(currentValue, prevValue);
        //     },
        //   },
        // },
      });
      vm.$watch("isHot", {
        immediate: true, // 初始化时让 handler 调用一下
        handler(currentValue, prevValue) {
          console.log(currentValue, prevValue);
        },
      });
    </script>
  </body>
</html>