事件处理

事件修饰符

修饰符3个：event，stop，self

//stop 阻止事件的传播

<div @click="fn($event)">
  内容2
  <div @click.stop="fn($event)">内容1</div>
</div>

new Vue({
  el: "#app",
  data: {
    
  },
  methods: {
    fn(e){
      console.log(e.currentTarget)
    }
  },
});
//prevent 阻止事件的默认行为

<form>
  <input type="text">
  <button @click.prevent="submit">提交</button>
</form>

new Vue({
    el: "#app",
    data: {
      
    },
    methods: {
      submit(){
        console.log(123)
      }
    },
  });
//capture 把冒泡改为捕获

<div @click.capture="fn($event)">
  内容2
  <div @click.capture="fn($event)">内容1</div>
</div>

new Vue({
    el: "#app",
    data: {
      
    },
    methods: {
      fn(e){
        console.log(e.currentTarget)
      }
    },
  });
//self 当currentTarget和target都是同一个时候才触发

<div @click.self="fn($event)">
  内容2
  <div @click.self="fn($event)">内容1</div>
</div>

new Vue({
  el: "#app",
  data: {
    
  },
  methods: {
    fn(e){
      console.log(e.currentTarget)
      console.log(e.target)
    }
  },
});
//once 只触发一次

<div @click.once="fn($event)">
  内容
</div>

new Vue({
  el: "#app",
  data: {
    
  },
  methods: {
    fn(e){
      console.log(e.currentTarget)
    }
  },
});
//passive 主动告诉浏览器不需要阻止事件的默认行为

//移动端 滑动屏幕 会发询问给浏览器 需不需要阻止这个事件
//passive 不需要问我，每次都不阻止。目的是提升浏览器的运行效率

按键修饰符

<input type="text" @keydown.q="fn">

new Vue({
  el: "#app",
  data: {
    
  },
  methods: {
    fn(){
      console.log(123)
    }
  },
});

练习

%accordion% 仅参考💢 %accordion%

<div id="app">
    <button @click="handlerClick($event)">按钮</button>
</div>

<script>
    new Vue({
        el: "#app",
        data: {},
        methods: {
            handlerClick(e) {
                console.log(e);
            }
        }
    })
</script>

<div id="app">
    <form>
        <input type="text">
        <button @click="submit($event)">提交</button>
    </form>
</div>

<script>
    new Vue({
        el: "#app",
        data: {},
        methods: {
            submit(e) {
                e.preventDefault();//阻止事件的默认行为
                console.log(123);
            }
        }
    })
</script>

%/accordion%

%accordion% 练习🚀 %accordion%

<div id="app">
    <form>
        <input type="text">
        <!-- <button @click.stop="submit()">按钮</button> -->
        <button @click.prevent="submit()">按钮</button>
    </form>
</div>

<script>
    new Vue({
        el: "#app",
        data: {
        },
        methods: {
            submit() {
                console.log(123);
            }
        }
    })
</script>

%/accordion%

%accordion% 点击事件练习🔨 %accordion%

添加了.self

<style>
    .a {
        width: 500px;
        height: 500px;
        background: red;
    }

    .b {
        width: 300px;
        height: 300px;
        background: #f0f;
    }
</style>
<div id="app">
    <div class="a" @click.self="handler($event)">
        <div class="b" @click.self="handler($event)"></div>
    </div>
</div>

<script>
    new Vue({
        el: "#app",
        data: {
        },
        methods: {
            handler(e) {
                // console.log(e.currentTarget) //冒泡事件 冒泡上去了就先b然后a
                console.log(e.target) //触发该元素，添加.self点击谁就是谁
            }
        },
    })
</script>

传播事件

<style>
    .a {
        width: 500px;
        height: 500px;
        background: red;
    }

    .b {
        width: 300px;
        height: 300px;
        background: #f0f;
    }
</style>
<div id="app">
    <div class="a" @click="handler($event)">
        <div class="b" @click="handler($event)"></div>
    </div>
</div>

<script>
    new Vue({
        el: "#app",
        data: {
        },
        methods: {
            handler(e) {
                // console.log(e.currentTarget) //冒泡事件 冒泡上去了就先b然后a
                console.log(e.target) //触发该元素，触发b就两个b咯，触发a就a咯
            }
        },
    })
</script>