改微信小程序子页面的tabbar的案例：
可在app.json中写的tabList中修改，例如在app.json中找到tabbar，设置tabbar的列表，也就是底部的菜单栏。
"list":[ { "pagePath":"pages/idndex/index", "text":"首页", "iconPath":"images/tabbar/tabbar1.png", "selectedIconPath":"images/tabbar/tabbar1_selected.png" }
{
"pagePath":"pages/idndex/index",
"text":"首页",
"iconPath":"images/tabbar/tabbar1.png",
"selectedIconPath":"images/tabbar/tabbar1_selected.png"
}
