Question

我正在尝试Flutter，我正在尝试更改应用中BottomNavigationBar的颜色，但我所能实现的只是更改了BottomNavigationItem（图标和文字）的颜色。

我在这里宣布我的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,
      ),
    );
  }

早些时候我以为我已经通过在我的主应用主题上编辑canvasColor绿色来解决这个问题，但它搞砸了整个应用配色方案：

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(),
    );
  }
}

Answer 1

没有选项可以指定BottomNavigationBar的背景颜色，但可以更改canvasColor。在不弄乱整个应用程序的情况下实现它的一种方法是将BottomNavigationBar包裹在Theme所需的canvasColor中。

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"),
        )
      ],
    ),
  ),

希望有所帮助！

Answer 2

如果类型固定，可以通过将颜色设置为backgroundColor属性来更改

。

BottomNavigationBar(
          backgroundColor: Colors.red,
          type: BottomNavigationBarType.fixed,
          items: [
            BottomNavigationBarItem(
                icon:Icon(Icons.home, color: Color.fromARGB(255, 255, 255, 255)),
                title: new Text('Home'),),
            BottomNavigationBarItem(
                icon: Icon(Icons.work,color: Color.fromARGB(255, 255, 255, 255)),
                title: new Text('Self Help'),),
            BottomNavigationBarItem(
                icon:Icon(Icons.face, color: Color.fromARGB(255, 255, 255, 255)),
                title: new Text('Profile'),),
          ]
        )

如果类型正在转换，它将在bottomNavigationBarItem内部使用颜色。

BottomNavigationBar(
          backgroundColor: Colors.red,
          type: BottomNavigationBarType.shifting,
          items: [
            BottomNavigationBarItem(
                icon:Icon(Icons.home, color: Color.fromARGB(255, 255, 255, 255)),
                title: new Text('Home'),
                backgroundColor: Colors.red),
            BottomNavigationBarItem(
                icon: Icon(Icons.work,color: Color.fromARGB(255, 255, 255, 255)),
                title: new Text('Self Help'),
                backgroundColor: Colors.blue),
            BottomNavigationBarItem(
                icon:Icon(Icons.face, color: Color.fromARGB(255, 255, 255, 255)),
                title: new Text('Profile'),
                backgroundColor: Colors.amber),
          ]

        )

即使我设置了backgroundColor属性，您也可以看到它不会应用该颜色，并且BottomNavigationBarItem小部件内的背景颜色将覆盖该颜色。

来自here

Answer 3

设置以下属性以更改背景，选定和未选定颜色

bottomNavigationBar: BottomNavigationBar(
        backgroundColor: Colors.blue,
        selectedItemColor: Colors.black,
        unselectedItemColor: Colors.white,
        type: BottomNavigationBarType.fixed,
        ...
)

Answer 4

您当前可以直接从BottomNavigationBar为Theme设置样式，如下所示：

ThemeData(
     
      bottomNavigationBarTheme: BottomNavigationBarThemeData(
        backgroundColor: Colors.grey[900],
        elevation: 10,
        selectedLabelStyle: TextStyle(
            color: Color(0xFFA67926), fontFamily: 'Montserrat', fontSize: 14.0),
        unselectedLabelStyle: TextStyle(
            color: Colors.grey[600], fontFamily: 'Montserrat', fontSize: 12.0),
        selectedItemColor: Color(0xFFA67926),
        unselectedItemColor: Colors.grey[600],
        showUnselectedLabels: true,
      ),

）

Answer 5

title已过时。我们改用label。
对于label，我们可以使用相应的属性：selectedLabelStyle, unselectedLabelStyle。
例如：

bottomNavigationBar: BottomNavigationBar(
          type: BottomNavigationBarType.fixed,
          selectedItemColor: Theme.of(context).accentColor,
          selectedFontSize: 0,
          unselectedFontSize: 0,
          iconSize: 22,
          elevation: 0,
          backgroundColor: Colors.transparent,
          selectedIconTheme: IconThemeData(size: 28),
          unselectedItemColor: Theme.of(context).focusColor.withOpacity(1),
          selectedLabelStyle: Theme.of(context).textTheme.bodyText1.merge(TextStyle(fontSize: 12)),
          unselectedLabelStyle: Theme.of(context).textTheme.button.merge(TextStyle(fontSize: 11)),
          showUnselectedLabels: true,
          currentIndex: widget.currentTabIdx,
          onTap: (int i) {
            this._selectTab(i);
          },
          showSelectedLabels: true,
          // this will be set when a new tab is tapped
          items: [
            BottomNavigationBarItem(
              icon: SvgPicture.asset(IMAGE_ASSETS_ICONS_HOME) ,
              activeIcon: SvgPicture.asset(IMAGE_ASSETS_ICONS_HOME, color: Theme.of(context).accentColor),
              label: 'Home',
            ),
            BottomNavigationBarItem(
                label: 'Categories',
              icon: SvgPicture.asset(IMAGE_ASSETS_ICONS_CATEGORY),
              activeIcon: SvgPicture.asset(IMAGE_ASSETS_ICONS_CATEGORY, color: Theme.of(context).accentColor) ,
            ),
            BottomNavigationBarItem(
              icon: SvgPicture.asset(IMAGE_ASSETS_ICONS_ORDER_HISTORY, ) ,
              activeIcon: SvgPicture.asset(IMAGE_ASSETS_ICONS_ORDER_HISTORY, color: Theme.of(context).accentColor ) ,
              label: 'Order History',
            ),
            BottomNavigationBarItem(
              icon: SvgPicture.asset(IMAGE_ASSETS_ICONS_CART,) ,
              activeIcon: SvgPicture.asset(IMAGE_ASSETS_ICONS_CART, color: Theme.of(context).accentColor) ,
              label: 'Cart',
            ),
          ],

Answer 6

只需按照下面给出的代码即可根据您的要求进行自定义。您只需要使用 Theme 设置 NavigationBar 的父级并设置 canvasColor 以更改背景颜色

      bottomNavigationBar: Theme(
    data: Theme.of(context).copyWith(
      canvasColor: kOrangeMaterialColor
    ),
    child: BottomNavigationBar(
      type: BottomNavigationBarType.shifting,
      currentIndex: _currentIndex,
      onTap: _onTapItem,

      items: [
        BottomNavigationBarItem(icon: Icon(Icons.home,
        color: kWhiteColor,),
        label: ''),
        BottomNavigationBarItem(icon: Icon(Icons.notifications,
        color: kWhiteColor,),
        label: ''),
        // BottomNavigationBarItem(icon: Icon(Icons.favorite_border,
        // color: kWhiteColor,),
       // label: ''),
        BottomNavigationBarItem(icon: Icon(Icons.account_circle,
        color: kWhiteColor,),
        label: ''),
        BottomNavigationBarItem(icon: Icon(Icons.settings,
        color: kWhiteColor,),
        label: ''),
      ],
    ),
  ),

Answer 7

只需将backgroundColor属性添加到BottomNavigationBar小部件。

@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,
        backgroundColor: Colors.black45,
      ),
    );
  }

Answer 8

接受的答案并非完全错误。但是，BottomNavigationBar实际上具有backgroundColor的属性。根据文档

如果类型为BottomNavigationBarType.shifting且项目设置为BottomNavigationBarItem.backgroundColor，则项目的backgroundColor将飞溅并覆盖此颜色。

这意味着BottomNavigation的backgroundColor将被单个项目backgroundColor覆盖，因为默认类型为BottomNavigationBarType.shifting。

要解决此问题，只需将以下属性添加到已声明的BottomNavigationbar小部件中即可。

type: BottomNavigationBarTyle.fixed,

注意：但是，如果要这样做，则需要转换效果，您必须为每个项目声明颜色，或包装允许覆盖子小部件背景颜色的小部件。

即Container小部件之类的东西。

Answer 9

以前没有直接设置颜色的方法，但是现在可以使用了。

BottomNavigationBar(
  backgroundColor: Colors.red,
  selectedItemColor: Colors.black,
  unselectedItemColor: Colors.white,
  ...
)

Answer 10

尝试将BottomNavigationBar包裹在Container中，然后设置其color。

示例：

@override
  Widget build(BuildContext context) {
    return new Scaffold(
      appBar: null,
      body: pages(),
      bottomNavigationBar:new Container(
        color: Colors.green,
        child: 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,
        ),
      );
    );
  };

Flutter中的Style BottomNavigationBar

10 个答案: