ElementUI之tree形下拉选

vue代码：

<el-row>
<el-col :span="11">
<el-form-item label="类型" prop="categoryId">
<SelectTree
:props="props"
:options="categoryList"
//数据源
:clearable="true"
:accordion="true"
:disableds="false"
@getValue="handleChange($event,row)"/>
//点击事件
</el-form-item>
</el-col>
</el-row>

import SelectTree from "@/views/SelectTree.vue";	//引入
data() {
return {
props:{
value: 'id',
label: 'label',
children: 'children',
},
}
}

SelectTree.vue

<template>
<el-select :value="valueTitle" :clearable="clearable" :disabled="disableds" @clear="clearHandle">
<el-option :value="valueTitle" :label="valueTitle" class="options">
<el-tree
id="tree-option"
ref="selectTree"
:accordion="accordion"
:data="options"
:props="props"
:node-key="props.value"
:default-expanded-keys="defaultExpandedKey"
@node-click="handleNodeClick">
</el-tree>
</el-option>
</el-select>
</template>
<script>
export default {
name: "el-tree-select",
props:{
/* 配置项 */
props:{
type: Object,
default:()=>{
return {
value:'id',
// ID字段名
label: 'label',
// 显示名称
children: 'children'
// 子级字段名
}
}
},
/* 选项列表数据(树形结构的对象数组) */
options:{
type: Array,
default: ()=>{ return [] }
},
/* 初始值 */
value:{
type: Number,
default: ()=>{ return null }
},
/* 可清空选项 */
clearable:{
type:Boolean,
default:()=>{ return true }
},
rules:{
type:Array
},
/* 禁用 */
disableds:{
type:Boolean,
default:()=>{ return true }
},
/* 自动收起 */
accordion:{
type:Boolean,
default:()=>{ return true }
},
},
data() {
return {
valueId:this.value,
// 初始值
valueTitle:'',
defaultExpandedKey:[]
}
},
mounted(){
this.initHandle()
},
methods: {
// 初始化值
initHandle(){
if(this.valueId){
this.valueTitle = this.$refs.selectTree.getNode(this.valueId).data[this.props.label]
// 初始化显示
this.$refs.selectTree.setCurrentKey(this.valueId)
// 设置默认选中
this.defaultExpandedKey = [this.valueId]
// 设置默认展开
}
this.initScroll()
},
// 初始化滚动条
initScroll(){
this.$nextTick(()=>{
let scrollWrap = document.querySelectorAll('.el-scrollbar .el-select-dropdown__wrap')[0]
let scrollBar = document.querySelectorAll('.el-scrollbar .el-scrollbar__bar')
scrollWrap.style.cssText = 'margin: 0px; max-height: none; overflow: hidden;'
scrollBar.forEach(ele => ele.style.width = 0)
})
},
// 切换选项
handleNodeClick(node){
this.valueTitle = node[this.props.label]
this.valueId = node[this.props.value]
this.$emit('getValue',this.valueId)
this.defaultExpandedKey = []
},
// 清除选中
clearHandle(){
this.valueTitle = ''
this.valueId = null
this.defaultExpandedKey = []
this.clearSelected()
this.$emit('getValue',null)
},
/* 清空选中样式 */
clearSelected(){
let allNode = document.querySelectorAll('#tree-option .el-tree-node')
allNode.forEach((element)=>element.classList.remove('is-current'))
}
},
watch: {
value(){
this.valueId = this.value
this.initHandle()
}
},
};
</script>
<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
.el-scrollbar .el-scrollbar__view .el-select-dropdown__item{
height: auto;
max-height: 274px;
padding: 0;
overflow: hidden;
overflow-y: auto;
}
.el-select-dropdown__item.selected{
font-weight: normal;
}
ul li >>>.el-tree .el-tree-node__content{
height:auto;
padding: 0 20px;
}
.el-tree-node__label{
font-weight: normal;
}
.el-tree >>>.is-current .el-tree-node__label{
color: #409EFF;
font-weight: 700;
}
.el-tree >>>.is-current .el-tree-node__children .el-tree-node__label{
color:#606266;
font-weight: normal;
}
</style>

java代码

@ResponseBody
@RequestMapping("/queryTreeData")
public List<TreeData<Category>> queryTreeData() {
TreeData<Category> tree = categoryService.queryTreeList();
return tree .getChildren();
}

public interface CategoryService {
TreeData<Category> queryTreeList();
}

@Service
@Transactional
public class CategoryServiceImpl implements CategoryService {
@Override
public TreeData<Category> queryTreeList() {
//查询源数据(根据实际情况调整)
List<Category> categoryList = categoryMapper.queryCategoryList();
//组织数据
List<TreeData<Category>> treeList = new ArrayList<>();
for (Category category: categoryList ) {
TreeData<Category> tree = new TreeData<>();
tree.setParentId(category.getCategoryPid());
tree.setId(category.getCategoryId());
tree.setLabel(category.getCategoryName());
tree.setDomPath(category.getPath());
treeList.add(tree);
}
// 默认顶级菜单数据库存为0，根据实际情况调整
TreeData<Category> tree = this.build(treeList);
return tree;
}
public static <T> TreeData<T> build(List<TreeData<T>> nodes) {
if (nodes == null) {
return null;
}
List<TreeData<T>> topNodes = new ArrayList<>();
for (TreeData<T> children : nodes) {
String pid = children.getParentId();
// 默认顶级菜单数据库存为0，根据实际情况调整
if (pid == null || "0".equals(pid)) {
topNodes.add(children);
continue;
}
for (TreeData<T> parent : nodes) {
String id = parent.getId();
if (id != null && id.equals(pid)) {
parent.getChildren().add(children);
children.setHasParent(true);
parent.setChildren(true);
continue;
}
}
}
TreeData<T> root = new TreeData<T>();
root.setId("-1");
root.setParentId("");
root.setHasParent(false);
root.setChildren(true);
root.setChecked(true);
root.setChildren(topNodes);
root.setLabel("顶级节点");
return root;
}
}

@Data
public class TreeData<T> {
private String id;//节点ID
private String parentId;//父ID
private String label;//显示节点文本
private String domPath;//结构
private List<TreeData<T>> children = new ArrayList<TreeData<T>>();//节点的子节点
private boolean checked = false;//节点是否被选中 true false
private boolean hasParent = false;//是否有父节点
private boolean hasChildren = false;//是否有子节点
private String domDesc;//备注
public void setChildren(boolean isChildren) {
this.hasChildren = isChildren;
}
public void setChildren(List<TreeData<T>> topNodes) {
this.children = topNodes;
}
}

最后

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