Blackscreen when navigate to new page flutter-CodePudding

At the moment I create an App where I display my sensor data in a List but my problem is that if I want to navigate to the List page I always get a Blackscreen. I tried to navigate like this:

Container(
                  height: 150.0,
                  margin: EdgeInsets.fromLTRB(75, 25, 75, 100),
                  child: Material(
                    borderRadius: BorderRadius.circular(20.0),
                    shadowColor: Colors.greenAccent,
                    color: Colors.green,
                    elevation: 7.0,
                    child: GestureDetector(
                      onTap: () {
                        Navigator.push(
                            context,
                            MaterialPageRoute(
                                builder: (context) =>  DataPage(key: null,)));

                      },

and I get the error

The argument type 'Null' can't be assigned to the parameter type 'Key'.

and that's part of my code for the List Page

class DataPage extends StatelessWidget {
  const DataPage({
    required Key key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text('Hive Test'),
        ),
        body: Column(
          children: <Widget>[
            Expanded(child: _buildListView()),
          ],
        ));
  }

with my current knowledge I don´t know how to solve my problem. Sorry for any grammar mistakes and I would be thankful for any help!

CodePudding user response：

It's happening because you're passing 'null' in Key while navigation to DataPage screen. Key is optional parameter, hence you can make it nullable this way.

Edits to your first snippet:

Container(
                  height: 150.0,
                  margin: EdgeInsets.fromLTRB(75, 25, 75, 100),
                  child: Material(
                    borderRadius: BorderRadius.circular(20.0),
                    shadowColor: Colors.greenAccent,
                    color: Colors.green,
                    elevation: 7.0,
                    child: GestureDetector(
                      onTap: () {
                        Navigator.push(
                            context,
                            MaterialPageRoute(
                                builder: (context) =>  DataPage()));

                      },

Edits to your second snippet:

class DataPage extends StatelessWidget {
  const DataPage({
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
        appBar: AppBar(
          title: Text('Hive Test'),
        ),
        body: Column(
          children: <Widget>[
            Expanded(child: _buildListView()),
          ],
        ));
  }

CodePudding user response：

your constructor in data page like this :

   const DataPage({Key? key}) : super(key: key);