Flutter Failed assertion: line 1890 pos 16: 'constraints.hasBoundedWidth':-CodePudding

I'm working with sqflite database, and I want to show the sum of all scores stored in my DB.

I have a screen where I show a banner inside widget Stack, and I need to show the sum just right there.

But I get this error Failed assertion:

Here is an example image, which is what I need to show the sum in Cumulative Score:

this is how I call my database List to show on screen, a Positioned widget inside a Stack

  Positioned(
    right: 40,
    child: Expanded(

      //calling database

      child: FutureBuilder<List<scoregamilibre>>(                        
        future: _scoregamilibreRC,
        builder: (BuildContext context,
            AsyncSnapshot<List<scoregamilibre>> snapshot) {
          if (snapshot.connectionState ==
              ConnectionState.waiting) {
            return const Center(
              child: CircularProgressIndicator(),
            );
          } else if (snapshot.hasError) {
            return Text('Error: ${snapshot.error}');
          } else {
            var items = snapshot.data ?? <scoregamilibre>[];

            print(items);

            return Container(
              margin: const EdgeInsets.symmetric(
                horizontal: 1.0,
                vertical: 1.0,
              ),
              decoration: BoxDecoration(
                borderRadius: BorderRadius.circular(12),
              ),
              child: ListView.builder(
                scrollDirection: Axis.vertical,
                shrinkWrap: true,
                itemCount: items.length,
                itemBuilder:
                    (BuildContext context, int index) {

                  //this are the scores parsed to int, to make the sum

                  int Ipos0 = int.parse(items[0].score);
                  int Ipos1 = int.parse(items[1].score);
                  int Ipos2 = int.parse(items[2].score);
                  int Ipos3 = int.parse(items[3].score);
                  int Ipos4 = int.parse(items[4].score);
                  int Ipos5 = int.parse(items[5].score);
                  int Ipos6 = int.parse(items[6].score);
                  int Ipos7 = int.parse(items[7].score);
                  int Ipos8 = int.parse(items[8].score);
                  int Ipos9 = int.parse(items[9].score);

                  int sumatoria = Ipos0  
                      Ipos1  
                      Ipos2  
                      Ipos3  
                      Ipos4  
                      Ipos5  
                      Ipos6  
                      Ipos7  
                      Ipos8  
                      Ipos9;

                  //here is where i try to show in Text widget

                  return GestureDetector(
                    onTap: () {},
                    child: Column(
                      children: [
                        SizedBox(height: 7),
                        const Text(
                          "Sum Score",
                          style: TextStyle(
                              color: Colors.black,
                              fontFamily: 'ZCOOL',
                              fontSize: 11),
                        ),
                        Text( 

                          //here is where it would be shown
                          sumatoria.toString(),
                          style: const TextStyle(
                            color: Colors.black,
                            fontFamily: 'ZCOOL',
                            fontSize: 22,
                          ),
                        ),
                      ],
                    ),
                  );
                },
              ),
            );
          }
        },
      ),
    ),
  )

but before I go to that screen, that error appears:

Exception has occurred.
_AssertionError ('package:flutter/src/rendering/viewport.dart': Failed assertion: line 1890 pos 16: 'constraints.hasBoundedWidth': is not true.)

How can I resolve this error? maybe calling the database in another way? or do the sum inside dbHelper.dart and deliver the sum variable of the scores through a method?

CodePudding user response：

The problem is that the ListView is only limited vertically by the shrinkWrap property. But horizontally, there is no limit on the left of the Positioned. To fix it do the following:

Remove the Expanded widget inside Positioned. This is because Expanded widgets make a child of a Row, Column, or Flex expand to fill the available space along the main axis -- but only in a Row, Column, or Flex. Mixing Positioned and Expanded is not OK.
Set the width of the Container to something like 100.0 (or set the Positioned.left). This will set the horizontal limits for the ListView.

The code is going to be like this:

Positioned(
  right: 40,
  child: FutureBuilder<List<scoregamilibre>>(
    future: _scoregamilibreRC,
    builder: (context, snapshot) {
      if (snapshot.connectionState == ConnectionState.waiting) {
        return const Center(
          child: CircularProgressIndicator(),
        );
      } else if (snapshot.hasError) {
        return Text('Error: ${snapshot.error}');
      } else {
        var items = snapshot.data ?? <scoregamilibre>[];

        print(items);

        return Container(
          width: 100,                                      // <- Here
          margin: const EdgeInsets.symmetric(
            horizontal: 1.0,
            vertical: 1.0,
          ),
          decoration: BoxDecoration(
            color: Colors.amber,
            borderRadius: BorderRadius.circular(12),
          ),
          child: ListView.builder(
            scrollDirection: Axis.vertical,
            shrinkWrap: true,
            itemCount: items.length,
            itemBuilder: (BuildContext context, int index) {
              //this are the scores parsed to int, to make the sum

              int Ipos0 = int.parse(items[0].score);
              int Ipos1 = int.parse(items[1].score);
              int Ipos2 = int.parse(items[2].score);
              int Ipos3 = int.parse(items[3].score);
              int Ipos4 = int.parse(items[4].score);
              int Ipos5 = int.parse(items[5].score);
              int Ipos6 = int.parse(items[6].score);
              int Ipos7 = int.parse(items[7].score);
              int Ipos8 = int.parse(items[8].score);
              int Ipos9 = int.parse(items[9].score);

              int sumatoria = Ipos0  
                  Ipos1  
                  Ipos2  
                  Ipos3  
                  Ipos4  
                  Ipos5  
                  Ipos6  
                  Ipos7  
                  Ipos8  
                  Ipos9;

              //here is where i try to show in Text widget

              return GestureDetector(
                onTap: () {},
                child: Column(
                  children: [
                    SizedBox(height: 7),
                    const Text(
                      "Sum Score",
                      style: TextStyle(
                          color: Colors.black,
                          fontFamily: 'ZCOOL',
                          fontSize: 11),
                    ),
                    Text(
                      //here is where it would be shown
                      sumatoria.toString(),
                      style: const TextStyle(
                        color: Colors.black,
                        fontFamily: 'ZCOOL',
                        fontSize: 22,
                      ),
                    ),
                  ],
                ),
              );
            },
          ),
        );
      }
    },
  ),
)