https://blog.csdn.net/woshisangsang/article/details/120035535
element级联（el-cascader）最后一层选不中
https://blog.csdn.net/wgb0409/article/details/122214760
需要把最后一层的ChildNodes设置为null或undefined
getTreeData(data) {
// 循环遍历json数据
for (var i = 0; i < data.length; i++) {
if (data[i].ChildNodes.length < 1) {
// children若为空数组，则将children设为undefined
data[i].ChildNodes = undefined;
} else {
// children若不为空数组，则继续 递归调用 本方法
this.getTreeData(data[i].ChildNodes);
}
}
return data;
},
