如何在 flutter 的底部导航栏中垂直和水平地在中心添加一个按钮？

Question

我尝试了很多不同的方法并在网上寻找解决方案，但找不到任何方法。有人可以帮我解决这个问题吗？我希望我的按钮位于底部导航栏的中间，如图 1 所示

the button is right in the middle which is what i want

this is a floating action button, however i cannot put it to the place i want

Answer 1

我会做的是 remove/replace 带有 BottomNavigationBarItem 的 FAB（浮动操作按钮）并将其放在 BottomNavigationBar 的中心并为其创建样式

这是一个例子：

    bottomNavigationBar: BottomNavigationBar(
    onTap: _selectTab,
    showSelectedLabels: false,
    showUnselectedLabels: false,
    backgroundColor: Theme.of(context).primaryColor,
    selectedItemColor: Theme.of(context).accentColor,
    unselectedItemColor: Colors.black,
    currentIndex: _selectedScreenIndex,
    //type: BottomNavigationBarType.shifting,
    items: [
      BottomNavigationBarItem(
        icon: Icon(
          Icons.category,
        ),
        label: 'Categories',
      ),
      BottomNavigationBarItem(
        icon: Container(
          decoration: BoxDecoration(
            color: Colors.yellow,
            shape: BoxShape.circle,
          ),
          child: Padding(
              padding: const EdgeInsets.all(8.0),
              child: IconButton(
                onPressed: () {},
                icon: Icon(
                  Icons.add,
                ),
                iconSize: 40,
              )
              // Icon(
              //   Icons.add,
              // ),
              ),
        ),
        label: 'Add',
      ),
      BottomNavigationBarItem(
        icon: Icon(
          Icons.star,
        ),
        label: 'Favorites',
      ),
    ],
  ),

底部导航也有这个替代选项https://pub.dev/packages/convex_bottom_bar

flutter dart flutter-widget flutter-bottomnavigation

如何在 flutter 的底部导航栏中垂直和水平地在中心添加一个按钮？

How do I add a button in the center both vertically and horizontally in a bottom navigation bar in flutter?

flutter

flutter-bottomnavigation