微信小程序更改下方导航

app.json

{
  "pages": [
    "pages/index/index",
    "pages/logs/logs",
    "pages/home/home"
  ],
  "window": {
    "backgroundTextStyle": "light",
    "navigationBarBackgroundColor": "#fff",
    "navigationBarTitleText": "商城",
    "navigationBarTextStyle": "black"
  },
  "sitemapLocation": "sitemap.json",
  "tabBar": {
    "color": "#a9b7b7",
    "selectedColor": "#11cd6e",
    "borderStyle": "white",
    "list": [
       {
         "pagePath":"pages/index/index",
         "iconPath":"images/nav/home-off.png",
         "selectedIconPath":"images/nav/home-on.png",
         "text":"首页"
       },
       {
          "pagePath": "pages/index/index",
          "iconPath": "images/nav/cart-off.png",
          "selectedIconPath": "images/nav/cart-on.png",
          "text": "购物车"
        },
        {
            "pagePath": "pages/index/index",
            "iconPath": "images/nav/my-off.png",
            "selectedIconPath": "images/nav/my-on.png",
            "text": "我的"
          }
      
    ]
  }
}