Flutter 应为Map String，dynamic类型的值，但得到的值为type()= Map String，dynamic'

我正在制作一个数据表，用于使用按钮进行筛选.我看了一个教程.

我必须创建一个对象(名为:Kasalar_object).在我的专栏中，我已经将StreamBuilder小部件命名为.我创造了我的DataSourceTable.

在那之后，我用我的DataSourceTable替换了我的来源，但我必须把我的价值观放在我的对象上.我试着把它放进go ，但我的应用程序显示:

应为‘Map&lt；字符串，动态&gt；’类型的值，但获得的类型为‘()=&gt；映射&lt；字符串，动态&gt；’

流媒体没有错误.因为当我试图在没有对象的情况下使用它时.它起作用了.以下是我的代码:

我的目标是:

class Kasalar_object  {
 final String kasa_adi;
 final String doviz_cinsi;
 final String acilis_bakiyesi;
 final String olusturulma_tarihi;
 final  String aktivite;

 Kasalar_object( {required this.kasa_adi , required this.doviz_cinsi, required this.acilis_bakiyesi, required this.olusturulma_tarihi, required this.aktivite});

//     Map<String, dynamic>
  factory Kasalar_object.fromMap( Map<String, dynamic> kasalar_objectim )  {
    return Kasalar_object(
      kasa_adi: kasalar_objectim['kasa_adi'],
      doviz_cinsi: kasalar_objectim['doviz_cinsi'],
      acilis_bakiyesi: kasalar_objectim['acilis_bakiyesi'],
    olusturulma_tarihi: kasalar_objectim['olusturulma_tarihi'],
    aktivite:  kasalar_objectim['aktivite'], ); // );   
  }

  StreamBuilder(
     stream:  firestore.collection("Users").doc(FirebaseAuth.instance.currentUser?.email).collection("kasalar").snapshots(),
     builder: (context, AsyncSnapshot<QuerySnapshot> snap) {
          List<Kasalar_object> kasalarim = [];

          kasalarim = snap.data!.docs.map((e) => Kasalar_object.fromMap(e.data() as Map<String, dynamic> )).toList();

            final DataTableSource _all_kasa = MyKasaData(kasalarim);

            List<dynamic> map = snap.data!.docs;

        if(snap.hasData ){
              return PaginatedDataTable(
                columns:  [        
                  DataColumn(label: Text('Kasa Adi'),),
                  DataColumn(label: Text('Para Birimi')),
                  DataColumn(label: Text('Açılıs Bakiyesi')),
                  DataColumn(label: Text('Oluşturulma Tarihi')),
                  DataColumn(label: Text('Aktif/Pasif')),
                  DataColumn(label: Text('İslemler')),
                ],
                source: _all_kasa,
                columnSpacing: witdh/15,
              );
        }
        else{
          return Center(child: CircularProgressIndicator()); // new Text('No data...');
        }
      }),

我的dataSourceTable:

class MyKasaData extends DataTableSource {    

  SideBarController sideBarController = Get.put(SideBarController());    

  // List<Kasalar> kasalar = [];

  MyKasaData(this._data);

  final List<dynamic> _data;

  DataRow getRow(int index) {
    return DataRow(cells: [
      DataCell(Text(_data[index].data()['kasa_adi'])),
      DataCell(Text(_data[index].data()['doviz_cinsi'])),
      DataCell(Text(_data[index].data()['acilis_bakiyesi'])),
      DataCell(Text(_data[index].data()['olusturulma_tarihi'])),
      DataCell(Text(_data[index].data()['aktivite'])), }

以下是错误消息的图像:

enter image description here个

如果我将数据更改为data()，则结果如下:

enter image description here个

我怎么才能修好它呢？