flutter - BottomNavigationBar无法应用背景图像-Flutter

Question

当 BottomNavigationBarItem 多于3个时， BottomNavigationBar 不应用背景图像。它显示白色背景而不是应用的图像。请查看代码，如果代码中缺少某些内容，请通知我。

 bottomNavigationBar: Container(
            decoration: BoxDecoration(
              image: DecorationImage(image: AssetImage('assets/images/tabbar_background.png'), fit: BoxFit.fill),
            ),
            child: BottomNavigationBar(
              backgroundColor: Colors.transparent,
              elevation: 0,
              items: [
                BottomNavigationBarItem(icon: Image.asset("assets/images/eplay.png"), title: Text('title')),
                BottomNavigationBarItem(icon: Image.asset("assets/images/games.png"), title: Text('title')),
                  BottomNavigationBarItem(icon: Image.asset("assets/images/retail-location.png"), title: Text('title')),
                 BottomNavigationBarItem(icon: Image.asset("assets/images/scan.png"), title: Text('title')),
                /*  BottomNavigationBarItem(icon: Image.asset("assets/images/scan.png"), title: Text('title')),
*/
              ],
            ),

Answer 1

将type: BottomNavigationBarType.fixed添加为BottomNavigationBar的属性。

我以您的代码为例添加了一个演示:

  bottomNavigationBar: Container(
            decoration: BoxDecoration(
              image: DecorationImage(image: AssetImage('assets/images/tabbar_background.png'), fit: BoxFit.fill),
            ),
            child: BottomNavigationBar(
              backgroundColor: Colors.transparent,
              type: BottomNavigationBarType.fixed, // new line
              elevation: 0,
              items: [
                BottomNavigationBarItem(icon: Image.asset("assets/images/eplay.png"), title: Text('title')),
                BottomNavigationBarItem(icon: Image.asset("assets/images/games.png"), title: Text('title')),
                  BottomNavigationBarItem(icon: Image.asset("assets/images/retail-location.png"), title: Text('title')),
                 BottomNavigationBarItem(icon: Image.asset("assets/images/scan.png"), title: Text('title')),
                /*  BottomNavigationBarItem(icon: Image.asset("assets/images/scan.png"), title: Text('title')),
*/
              ],
            ),