Flutter中的样式BottomNavigationBar [英] Style BottomNavigationBar in Flutter

问题描述

我正在尝试Flutter，并且尝试在应用程序上更改 BottomNavigationBar 的颜色，但我能做的就是更改<$ c $的颜色c> BottomNavigationItem （图标和文字）。

I am trying out Flutter and I am trying to change the colour of the BottomNavigationBar on the app but all I could achieve was change the colour of the BottomNavigationItem (icon and text).

在这里我声明我的 BottomNavigationBar ：

class _BottomNavigationState extends State<BottomNavigationHolder>{

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: null,
      body: pages(),
      bottomNavigationBar:new BottomNavigationBar(
        items: <BottomNavigationBarItem>[
          new BottomNavigationBarItem(
              icon: const Icon(Icons.home),
              title: new Text("Home")
          ),
          new BottomNavigationBarItem(
              icon: const Icon(Icons.work),
              title: new Text("Self Help")
          ),
          new BottomNavigationBarItem(
              icon: const Icon(Icons.face),
              title: new Text("Profile")
          )
        ],
        currentIndex: index,
        onTap: (int i){setState((){index = i;});},
        fixedColor: Colors.white,
      ),
    );
  }

我以前以为我是通过编辑来解决这个问题的canvasColor 在我的主应用程序主题上变为绿色，但它弄乱了整个应用程序的配色方案：

Earlier I thought I had it figured out by editing canvasColor to green on my main app theme but it messed up the entire app colour scheme:

class MyApp extends StatelessWidget {
  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      title: 'Flutter Demo',
      theme: new ThemeData(
        primarySwatch: Colors.blue,
        canvasColor: Colors.green
      ),
      home: new FirstScreen(),
    );
  }
}

推荐答案

有不能指定 BottomNavigationBar 的背景颜色，而只能更改 canvasColor 。您可以在不弄乱整个应用程序的情况下实现此目标的一种方法是，将 BottomNavigationBar 包装在具有所需<$的主题中c $ c> canvasColor 。

There is no option to specify the background color of BottomNavigationBar but to change the canvasColor. One way you can achieve it without messing up the whole app would be by wrapping BottomNavigationBar in a Theme with desired canvasColor.

示例：

  bottomNavigationBar: new Theme(
    data: Theme.of(context).copyWith(
        // sets the background color of the `BottomNavigationBar`
        canvasColor: Colors.green,
        // sets the active color of the `BottomNavigationBar` if `Brightness` is light
        primaryColor: Colors.red,
        textTheme: Theme
            .of(context)
            .textTheme
            .copyWith(caption: new TextStyle(color: Colors.yellow))), // sets the inactive color of the `BottomNavigationBar`
    child: new BottomNavigationBar(
      type: BottomNavigationBarType.fixed,
      currentIndex: 0,
      items: [
        new BottomNavigationBarItem(
          icon: new Icon(Icons.add),
          title: new Text("Add"),
        ),
        new BottomNavigationBarItem(
          icon: new Icon(Icons.delete),
          title: new Text("Delete"),
        )
      ],
    ),
  ),

希望有帮助！

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