I'm trying to implement this bottom nav bar in flutter, but the book now button isn't placing properly. how can I achieve this type of bottom nav bar??

CodePudding user response：

Here is custom bottom navigator without package

First create page controller and variable for controlling the index like this

int _currentIndex = 0;
  final PageController _pageController = PageController();

then here is the body

Scaffold(
    body: PageView(
      controller: _pageController,
      // physics: const NeverScrollableScrollPhysics(), if you dont want swip physics
      onPageChanged: (index) {
        setState(() => _currentIndex = index);
      },
      children: <Widget>[
        Container(
          child: Center(
            child: Container(
              width: 50,
              height: 50,
              color: Colors.purple,
            ),
          ),
        ),
        Container(
          child: Center(
            child: Container(
              width: 50,
              height: 50,
              color: Colors.red,
            ),
          ),
        ),
        Container(
          child: Center(
            child: Container(
              width: 50,
              height: 50,
              color: Colors.blue,
            ),
          ),
        ),
      ],
    ),

    bottomNavigationBar: Padding(
      padding: const EdgeInsets.fromLTRB(15, 5, 15, 10),
      child: Container(
        height: MediaQuery.of(context).size.height * .09,
        decoration: BoxDecoration(
            color: Colors.purple,
            borderRadius: const BorderRadius.all(Radius.circular(25)),
            boxShadow: [
              BoxShadow(
                  color: Colors.grey.shade300,
                  spreadRadius: 3,
                  blurRadius: 5)
            ]),
        child: Row(
          mainAxisAlignment: MainAxisAlignment.spaceEvenly,
          children: [
            IconButton(
                onPressed: () => setState(() {
                  _currentIndex = 0;
                  _pageController.animateToPage(0,
                      duration: const Duration(milliseconds: 200),
                      curve: Curves.ease);
                }),
                icon: Icon(
                  _currentIndex == 0 ? Icons.home : Icons.home_outlined,
                  color: _currentIndex == 0
                      ? Colors.blue.shade700
                      : Colors.white,
                )),
            IconButton(
                onPressed: () => setState(() {
                  _currentIndex = 1;
                  _pageController.animateToPage(1,
                      duration: const Duration(milliseconds: 200),
                      curve: Curves.ease);
                }),
                icon: Icon(
                  _currentIndex == 1
                      ? CupertinoIcons.heart_solid
                      : CupertinoIcons.heart,
                  color: _currentIndex == 1
                      ? Colors.blue.shade700
                      : Colors.white,
                )),
            IconButton(
                onPressed: () => setState(() {
                  _currentIndex = 3;
                  _pageController.animateToPage(3,
                      duration: const Duration(milliseconds: 200),
                      curve: Curves.ease);
                }),
                icon: Icon(
                  _currentIndex == 3
                      ? CupertinoIcons.person_fill
                      : CupertinoIcons.person,
                  color: _currentIndex == 3
                      ? Colors.blue.shade700
                      : Colors.white,
                )),
          ],
        ),
      ),
    )
);

here is the result