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

i have tried so many different ways und looked for solutions online, but could not find any. can someone please help me with this problem? i want my button right in the middle of the bottom navigation bar like in picture 1

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

What I would do is remove/replace the FAB (Floating action button) with a BottomNavigationBarItem and put it in the center of the BottomNavigationBar and create styling for it

Here is an example:

    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',
      ),
    ],
  ),

Also there is this alternative option for the bottom navigation https://pub.dev/packages/convex_bottom_bar

flutter dart flutter-widget flutter-bottomnavigation