After many attempts and trying different things, I get the same error ( throw constraintsError ) as soon as I add Expanded, while the error disappears by deleting it,, i I want the upper part to be fixed and the other part to be Scrollable

thanks

SingleChildScrollView(
    child: Column(
         children: [ 
           Column(
            children: [
               Container(), // fixed
               Row(), // fixed
               **Expanded**(
                 child: Container(
                    color: constants.kLightGrayColor,
                    child: ListView.builder(
                    scrollDirection: Axis.vertical,
                    shrinkWrap: true,
                    controller: controller.scrollController,
                    itemCount: data.posts.length,
                    itemBuilder: (context, index) {

CodePudding user response：

firstly cannot used Expanded inside SingleChildScrollView. to work normally pls remove SingleChildScrollView widget and remove outer Column, used one of Column in green box. it is small example

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(),
      body: Column(
        children: [
          Container(
            height: 200,
            width: MediaQuery.of(context).size.width,
            color: Colors.red,
            child: const Center(child: Text("Fixed Box")),
          ),
          Expanded(
            child: ListView.builder(
              shrinkWrap: true,
              itemCount: 20,
              itemBuilder: (context, index) {
                return ListTile(
                  title: Text("$index"),
                );
              },
            ),
          ),
        ],
      ),
    );
  }