微信小程序设置地图组件的covers的iconPath属性怎么设置都无效

app.json文件面看自tabBar写

"tabBar":{
"selectedColor": "#3cc51f",
"list":[{
"pagePath":"pages/index/index",
"iconPath":"images/icon_home.png",
"selectedIconPath":"images/icon_home_selected.png",
"text":"主页"
},{
"pagePath":"pages/car/index",
"iconPath":"images/icon_home.png",
"selectedIconPath":"images/icon_home_selected.png",
"text":"购物车"
},{
"pagePath":"pages/member/index/index",
"iconPath":"images/icon_member.png",
"selectedIconPath":"images/icon_member_selected.png",
"text":"员"
},{
"pagePath":"pages/store/index/index",
"iconPath":"images/20170811112822.png",
"selectedIconPath":"images/20170811113017.png",
"text":"商家"
}]
}
我知道设置5少没留意 能设置太少吧 设置几试试