ztree树中，一级节点图标如何显示成文件夹

Question

ztree树中，如果一级节点没有子节点，图标显示成文件夹的形式，而不是文件的形式，该怎么设置？
我的setting是这样设置的：

 setting: {
    data: {
        simpleData: {
            idKey: 'catId',
            pIdKey: 'parentId'
        },
        key: {
            name: 'catName',
            children: 'childCategories'
        }
    },
    check: {
        enable: true,
        chkboxType: {'Y': '', 'N': ''}
    }
}

树节点mock数据：

 {
    "catId": 750620002,
    "catLevel": 1,
    "catName": "crossCateName1",
    "catNameEn": "crossCateNameEn1",
    "childCategories": [
        {
            "catId": 750620001,
            "catLevel": 2,
            "catName": "crossCateName2",
            "catNameEn": "crossCateNameEn2",
            "childCategories": [
                {
                    "catId": 750620000,
                    "catLevel": 3,
                    "catName": "crossCateName3",
                    "catNameEn": "crossCateNameEn3",
                    "parentId": 750620001,
                    "productPicType": 1,
                    "sortOrder": 1,
                    "status": 1
                }
            ],
            "parentId": 750620002,
            "sortOrder": 1,
            "status": 1
        }
    ],
    "parentId": 750620003,
    "sortOrder": 1,
    "status": 1
},
{
    "catId": 750611326,
    "catLevel": 1,
    "catName": "RanTest4",
    "catNameEn": "RanTest4IN",
    "sortOrder": 1,
    "status": 1
},
{
    "catId": 750611325,
    "catLevel": 1,
    "catName": "RanTest3",
    "catNameEn": "RanTest3",
    "sortOrder": 1,
    "status": 1
}

Answer 1

给没有子节点的父节点增加属性 isParent:true。
如果一个节点是父节点但是没有子节点，需要增加属性 isParent:true。

{
    "catId": 750611325,
    "catLevel": 1,
    "catName": "RanTest3",
    "catNameEn": "RanTest3",
    "sortOrder": 1,
    "status": 1,
    "isParent":true
}

Answer 2

给RanTest4加一个空子类数组试试，如：

{
    "catId": 750611326,
    "catLevel": 1,
    "catName": "RanTest4",
    "catNameEn": "RanTest4IN",
    "sortOrder": 1,
    "status": 1,
    "childCategories": []
}