废话少说，能看懂就看，看不懂路过，解释了你也未必懂，直接上代码。
效果图：
这个demo需要6张图片：
做好好三个界面并注册，界面的数量要大于1小于6：
app.json代码：
{
"pages":[
"pages/index/index",
"pages/index2/index2",
"pages/index3/index3"
],
"window":{
"backgroundTextStyle":"light",
"navigationBarBackgroundColor": "#fff",
"navigationBarTitleText": "tabBar",
"navigationBarTextStyle":"black"
},
"tabBar": {
"position":"bottom",
"borderStyle":"white",
"list": [
{
"pagePath": "pages/index/index",
"text": "阅读",
"iconPath":"/images/ciwei.png",
"selectedIconPath":"/images/ciwei_hl.png"
},
{
"pagePath": "pages/index2/index2",
"text": "电影",
"iconPath": "/images/dianying.png",
"selectedIconPath": "/images/dianying_hl.png"
},
{
"pagePath": "pages/index3/index3",
"text": "我的",
"iconPath": "/images/yuedu.png",
"selectedIconPath": "/images/yuedu_hl.png"
}
]
}
}