我设置的tabbar背景色是白色，iphone预览却是黑色，，，安卓可以正常预览

下面是代码

{

“pages”:[

“pages/index/index”

],

“window”:{

“backgroundTextStyle”:“light”,

“navigationBarBackgroundColor”: “#fff”,

“navigationBarTitleText”: “WeChat”,

“navigationBarTextStyle”:“black”

},

“tabBar”: {

“backgroundColor”:“white”,

“list”: [{

“pagePath”: “pages/index/index”,

“text”: “text”,

“iconPath”: “pages/icon/index.png”,

“selectedIconPath”: “pages/icon/index_sele.png”

},{

“pagePath”: “pages/index/index”,

“text”: “text”,

“iconPath”: “pages/icon/message.png”,

“selectedIconPath”: “pages/icon/message_sele.png”

}]

}

}