Based on the code you provided, it seems like the InkWell widget is being wrapped inside a Row widget, which could be causing it to not show up on top of the blue Container. The InkWell widget needs to be a direct child of the Stack widget in order to be positioned on top of the blue Container.
Try removing the Row widget and placing the InkWell widget directly inside the Stack widget. Here's an updated code snippet:
Stack(
children: [
Container(height: 280, color: Colors.blue),
InkWell(
onTap: () {
Navigator.of(context).pushReplacement(MaterialPageRoute(builder: (context) => Mainpage()));
},
splashColor: Colors.brown.withOpacity(0.5),
child: Ink(
height: 48,
width: 48,
decoration: const BoxDecoration(
image: DecorationImage(
image: AssetImage('assets/dagger.png'),
fit: BoxFit.cover,
),
),
),
),
],
),
This should position the InkWell widget on top of the blue Container.