微信小程序 TabBar怎么设置默认选中？app.json中，tabbar按照如下写法，进入界面默认选择第一个tab(代码中为“首页”)

"tabBar": {
    "list": [
      {
        "pagePath": "pages/index/index",
        "text": "首页",
        "iconPath": "/images/icon/home.png",
        "selectedIconPath": "/images/icon/home.png"
      },
      {
          "pagePath": "pages/message/message",
          "text": "消息",
          "iconPath": "images/icon/message.png",
          "selectedIconPath": "images/icon/message.png"
      },
      {
      	"pagePath": "pages/my/my",
      	"text": "我",
      	"iconPath": "/images/icon/my.png",
      	"selectedIconPath": "/images/icon/my.png"
      }
  ]
  }

假如我想把“消息”栏放在第一个，且默认选中，该怎么做？我自然而然的修改了”tabBar”里的顺序，如下：

"tabBar": {
    "list": [
      {
          "pagePath": "pages/message/message",
          "text": "消息",
          "iconPath": "images/icon/message.png",
          "selectedIconPath": "images/icon/message.png"
      },{
        "pagePath": "pages/index/index",
        "text": "首页",
        "iconPath": "/images/icon/home.png",
        "selectedIconPath": "/images/icon/home.png"
      },
      {
      	"pagePath": "pages/my/my",
      	"text": "我",
      	"iconPath": "/images/icon/my.png",
      	"selectedIconPath": "/images/icon/my.png"
      }
  ]
  }

改完一运行，发现“消息”栏虽然显示在第一个了，但是默认选中的还是“首页”…

研究了一下，发现如果想修改默认选中的tab，只需要修改”pages”数组里的顺序即可，放在前面的会优先选中。
所以，此处应该这么改：

"pages": [
    "pages/message/message",
    "pages/index/index",
    "pages/my/my"
  ],

OK，就这样搞定了！