特性：

1. 支持自定义折叠状态
2. 支持自定义标签名称

sgCollapseBtn源码 

<template>
  <div :class="$options.name" @click="show = !show" :placement="placement">
    <div class="collapse-btns">
      <div class="collapse-btn" v-if="show">
        <i class="el-icon-caret-top"></i>
        <div class="label">折叠{{ collapseLabel || expandLabel || `` }}</div>
      </div>
      <div class="collapse-btn" v-else>
        <i class="el-icon-caret-bottom"></i>
        <div class="label">展开{{ expandLabel || collapseLabel || `` }}</div>
      </div>
    </div>
  </div>
</template>

<script>
export default {
  name: "sgCollapseBtn",
  components: {},
  data() {
    return {
      show: false,
    };
  },
  props: ["data", "value", "collapseLabel", "expandLabel", "placement"],
  watch: {
    value: {
      handler(d) {
        this.show = d;
      },
      deep: true,
      immediate: true,
    },
    show(d) {
      this.$emit("input", d);
    },
  },
  created() {},
  mounted() {},
  computed: {},
  methods: {},
};
</script>

<style lang="scss" scoped>
.sgCollapseBtn {
  position: relative;
  z-index: 1;
  /*禁止选中文本*/
  user-select: none;
  width: 100%;
  height: 30px;
  line-height: 30px;
  background-color: white;
  cursor: pointer;
  
  &[placement="bottom"] {
    position: absolute;
    top: revert;
    bottom: 0;
    left: 0;
    right: 0;
  }

  .collapse-btns {
    width: 100%;
    $side: 20%; //渐变边界
    /*左右渐变遮罩(兼容IOS)*/
    -webkit-mask-image: linear-gradient(
      to right,
      transparent,
      white $side,
      white calc(100% - #{$side}),
      transparent
    );
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 14px;
    background-color: white;
    &::after {
      content: "";
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      background: linear-gradient(white, #e2f0ff);
      opacity: 0;
      transition: 1s ease !important;
      z-index: -1;
    }
    .collapse-btn {
      transition: 0.4s !important;
      display: flex;
      align-items: center;
      transform: translateX(40%);
      i {
        transition: 0.4s !important;
        color: #d3dce6;
      }
      .label {
        transition: 0.2s !important;
        margin-left: 25px;
        color: #409eff;
        opacity: 0;
      }
    }
  }

  &:active,
  &:hover {
    .collapse-btns {
      &::after {
        opacity: 1;
      }
      .collapse-btn {
        transform: translateX(0%);

        i {
          color: #409eff;
        }
        .label {
          margin-left: 5px;
          color: #409eff;
          opacity: 1;
          // width: 100%;
        }
      }
    }
  }
}
</style>

应用

<template>
  <div :class="$options.name">
    <!-- 折叠按钮 -->
    <sgCollapseBtn v-model="expandSearch" :placement="`bottom`" :collapseLabel="``" />
  </div>
</template>
<script>
import sgCollapseBtn from "@/vue/components/admin/sgCollapseBtn";
export default {
  name: "sgComponent",
  components: { sgCollapseBtn },
  data() {
    return {
      expandSearch: false,
    };
  },
  props: ["value"],
  computed: {},
  watch: {},
  created() {},
  mounted() {},
  methods: {},
  destroyed() {},
};
</script>
<style lang="scss" scoped>
.sgComponent {
}
</style>