简易搜索组件（vue键盘事件）

<template>
  <div class="hello">
    <h1>值：{{text}}</h1>
    <div
      class="box"
      @keydown.down="increment"
      @keydown.up="decrement"
      @keydown.enter="go"
    >
      <div class="search_box">
        <div class="search_box_wrapper">
          <input
            id="search"
            ref="search"
            v-model="q"
            class="search_input"
            placeholder="搜索"
            type="search"
            autocomplete="off"
            @focus="onFocus"
            @blur="onBlur"
          />
        </div>
        <ul
          v-show="focus && results.length"
          class="search_list"
          style="margin-top: 37px"
        >
          <li
            v-for="(result, index) of results"
            :key="result.title + index"
            @mouseenter="focusIndex = index"
            @mousedown="go"
          >
            <div
              class="link"
              :class="{
                link_active: focusIndex === index,
              }"
              @click="focus = false"
            >
              <span v-if="result.title" style="font-weight: bold">{{
                result.title
              }}</span>
            </div>
          </li>
        </ul>
      </div>
    </div>
  </div>
</template>

<script>
export default {
  name: "HelloWorld",
  data() {
    return {
      q: "",
      focus: false,
      focusIndex: -1,
      allResults: [
        { title: '1' },
        { title: '11' },
        { title: '2' },
        { title: '22' },
        { title: '3' },
        { title: '33' },
        { title: '4' },
        { title: '44' },
        { title: '5' },
        { title: '55' },
      ],
      results: [],
      text: ''
    };
  },
  watch: {
    q(q) {
      this.focusIndex = -1
      if (!q) {
        this.results = []
        return
      }
      this.results = []
      for (let i = 0; i < this.allResults.length; i++) {
        if(this.allResults[i].title.includes(q)) {
          this.results.push(this.allResults[i])
        }
      }
    }
  },
  methods: {
    onFocus() {
      this.focus = true;
      this.$emit("focus", true);
    },
    onBlur() {
      this.focus = false;
      this.$emit("focus", false);
    },
    increment() {
      if (this.focusIndex < this.results.length - 1) {
        this.focusIndex++;
      }
    },
    decrement() {
      if (this.focusIndex >= 0) {
        this.focusIndex--;
      }
    },
    go() {
      if (this.results.length === 0) {
        return;
      }
      this.$refs.search.blur();
      this.q = "";
      this.text = this.results[this.focusIndex].title
    },
  },
};
</script>


<style scoped>
ul {
  list-style: none;
  margin: 0;
  padding: 0;
  margin-bottom: 1.25rem;
}
li {
  position: relative;
  padding-left: 1.75em;
  margin: 0.5rem 0;
}
.hello {
  width: 100%;
  height: 100%;
}
.box {
  display: block;
  width: 100%;
  position: relative;
  display: flex;
  flex-direction: column;
  /* align-items: center; */
  justify-content: space-between;
}
.search_box {
  width: 100%;
}
.search_box_wrapper {
  position: relative;
}
.search_input {
  display: block;
  width: 100%;
  padding: 0.5rem 0.75rem 0.5rem 2.5rem;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  line-height: 1.25rem;
  border: 1px solid transparent;
  color: #374151;
  border-radius: 0.375rem;
  background: #e5e7eb;
}
.search_input::placeholder {
  color: #6b7280;
}
.search_input:focus {
  border-color: #d1d5db;
  outline: none;
  background: white;
}
.search_list {
  position: absolute;
  width: 100%;
  flex: 1;
  top: 0;
  background: white;
  border: 1px solid #d1d5db;
  overflow: hidden;
  z-index: 10;
  border-radius: 0.375rem;
  max-height: 500px;
  overflow-y: auto;
}
.link_active {
  color: #10b981;
  background: #e5e7eb;
}
</style>