树状结构加减号

src/components/mechanismTree/index.vue

@@ -23,6 +23,7 @@
           class="filter-tree tree-line"
           :data="treeData"
           :props="defaultProps"
+          icon-class="icon-tree"
           :check-strictly="true"
           :current-node-key="nodeKeyId"
           node-key="id"
@@ -169,6 +170,12 @@ export default {
 </script>
 
 <style lang="less" scoped>
+/deep/ .icon-tree {
+  margin: 0 5px 0 10px;
+  position: relative;
+  background: url('~@/assets/images/shangqi/img/tree-add.png');
+  background-size: 100% 100%;
+}
 /deep/ .el-tree-node__content {
   padding-left: 0px !important;
 }