el-tree组件图标的自定义

el-tree组件图标的自定义：

通过content 属性与 :before 伪元素配合使用，在元素头来插入生成内容。

一、方法一：当所需图标存在于content的字符集时

content字符集

<template>
  <!-- el-tree组件图标自定义 -->
  <div class="page_one">
    <el-tree :data="data" :props="defaultProps"></el-tree>
  </div>
</template>

<script lang="ts">
import { defineComponent, reactive, toRefs } from "vue";
export default defineComponent({
  name: "pageOne",
  setup() {
    const state = reactive({
      data: [
        {
          label: "一级 1",
          children: [
            {
              label: "二级 1-1",
              children: [
                {
                  label: "三级 1-1-1",
                },
              ],
            },
          ],
        },
        {
          label: "一级 2",
          children: [
            {
              label: "二级 2-1",
              children: [
                {
                  label: "三级 2-1-1",
                },
              ],
            },
            {
              label: "二级 2-2",
              children: [
                {
                  label: "三级 2-2-1",
                },
              ],
            },
          ],
        },
        {
          label: "一级 3",
          children: [
            {
              label: "二级 3-1",
              children: [
                {
                  label: "三级 3-1-1",
                },
              ],
            },
            {
              label: "二级 3-2",
              children: [
                {
                  label: "三级 3-2-1",
                },
              ],
            },
          ],
        },
      ],
      defaultProps: {
        children: "children",
        label: "label",
      },
    });
    return {
      ...toRefs(state),
    };
  },
});
</script>

<style scoped lang="scss">
.page_one {
  height: 600px;
  width: 230px;
  display: flex;
  flex-direction: column;
  :deep().el-tree {
    flex: 1;
    color: #fff;
    background-image: linear-gradient(to bottom right, #3c5575, #01060c);
    .el-tree-node {
      margin-left: 10px;
    }
    .el-tree-node__content:hover {
      background: rgba(255, 0, 0, 0) !important;
    }
    .el-tree-node:focus > .el-tree-node__content {
      color: #fff !important;
      background: #364354 !important;
      height: 40px;
    }
    //原有的箭头 去掉
    .el-icon svg {
      display: none;
      height: 0;
      width: 0;
    }
    //引入图标的位置
    .el-tree-node__expand-icon {
      position: absolute;
      right: 4px;
      // 图标是否旋转，如果是箭头类型的，可以设置旋转90度。
      .expanded {
        transform: rotate(90deg);
      }
      // 未展开的节点
      &:before {
        // content: "\009B";
        content: "\00BB";
        font-size: 12px;
        color: #fff;
      }
    }
    // 叶子节点（不显示图标）
    .is-leaf.el-tree-node__expand-icon::before {
      display: block;
      background: none !important;
      content: "";
      width: 18px;
      height: 18px;
    }
  }
}
</style>

方法二：通过设置背景图片

<style scoped lang="scss">
.page_two {
  height: 600px;
  width: 230px;
  display: flex;
  flex-direction: column;
  :deep().el-tree {
    flex: 1;
    color: #fff;
    background-image: linear-gradient(to bottom right, #3c5575, #01060c);
    .el-tree-node__content:hover {
      background: rgba(255, 0, 0, 0) !important;
    }
    .el-tree-node:focus > .el-tree-node__content {
      color: #fff !important;
      background: #364354 !important;
      height: 40px;
    }
  }
}

:deep().el-tree .el-icon svg {
  //原有的箭头 去掉
  display: none !important;
  height: 0;
  width: 0;
}

//图标是否旋转，如果是箭头类型的，可以设置旋转90度。如果是两张图片，则设为0
:deep().el-tree {
  .el-tree-node__expand-icon {
    //引入的图标（图片）size大小 => 树节点前的预留空间大小
    font-size: 18px;
    &.expanded {
      -webkit-transform: rotate(0deg);
      transform: rotate(0deg);
      &:before {
        //展开的节点
        background: url("@/assets/2.png") no-repeat center center;
        background-size: cover;
        content: "";
        display: block;
        width: 18px;
        height: 18px;
      }
    }
    &:before {
      // 未展开的节点
      background: url("@/assets/1.png") no-repeat center center;
      background-size: cover;
      content: "";
      display: block;
      width: 18px;
      height: 18px;
    }
  }
}

:deep().el-tree .is-leaf.el-tree-node__expand-icon::before {
  //叶子节点（不显示图标）
  display: block;
  background: none !important;
  content: "";
  width: 18px;
  height: 18px;
}
</style>