dart - BottomNavigationBarItem 中添加的四个图标不起作用

Question

我是 Flutter 的新手 我在尝试添加四个图标时创建了一个底部导航栏。图标颜色变为白色。我应该如何实现这一点，任何人都可以建议我。下面是我的代码。任何帮助将不胜感激。

 bottomNavigationBar: new BottomNavigationBar(items: [
    new BottomNavigationBarItem(icon: new Icon(Icons.add), title: new Text("Text")),
    new BottomNavigationBarItem(icon: new Icon(Icons.person), title: new Text("Contact")),
    new BottomNavigationBarItem(icon: new Icon(Icons.accessibility), title: new Text("Acess")),
    new BottomNavigationBarItem(icon: new Icon(Icons.account_balance), title: new Text("Balance"))
  ]),

Answer 1

当元素超过3个时，需要显式设置type: BottomNavigationBarType.fixed,

bottomNavigationBar: new BottomNavigationBar(
    type: BottomNavigationBarType.fixed,
    items: [
    new BottomNavigationBarItem(icon: new Icon(Icons.add), title: new Text("Text")),
    new BottomNavigationBarItem(icon: new Icon(Icons.person), title: new Text("Contact")),
    new BottomNavigationBarItem(icon: new Icon(Icons.accessibility), title: new Text("Acess")),
    new BottomNavigationBarItem(icon: new Icon(Icons.account_balance), title: new Text("Balance"))
  ]),

When more than 3 BottomNavigationBar items are provided the type, if unspecified, changes to BottomNavigationBarType.shifting per https://docs.flutter.io/flutter/material/BottomNavigationBar/BottomNavigationBar.html.