为什么tabBar底部图标不显示？

{

“pagePath”: “pages/logs/logs”,

“text”: “首页”,

“iconPath”: “icons/r.png”,

“selectedIconPath”: “icons/rr.png”

},

{

“pagePath”: “pages/logs/logs”,

“text”: “日志”,

“iconPath”: “icons/a.png”,

“selectedIconPath”: “icons/aa.png”

}