How to get total selected rows apart from filtering in Flutter DataTable (SfDataGrid)?

In this article, we will show you how to get total selected rows apart from filtering in Flutter DataTable.

Initialize the SfDataGrid with the necessary properties. Maintain a flag list to track selected rows. Use the onSelectionChanged event to add or remove rows from this list as they are selected or deselected. This callback is triggered after a row is selected. By accessing the list, you can retrieve the total number of selected rows, even after filtering.

@override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: const Text('Syncfusion Flutter DataGrid')),
      body: Column(
        children: [
          TextButton(
            child: const Text('Total selected rows'),
            onPressed: () {
              // Get total selected rows by accessing the flag list.
              showDialog(
                context: context,
                builder: (BuildContext context) {
                  return AlertDialog(
                    title: const Text('Selected Rows'),
                    content: Text(
                      'Total selected rows: ${selectedRows.length}',
                    ),
                    actions: [
                      TextButton(
                        onPressed: () {
                          Navigator.of(context).pop();
                        },
                        child: const Text('OK'),
                      ),
                    ],
                  );
                },
              );
            },
          ),
          Expanded(
            child: SfDataGrid(
              controller: dataGridController,
              source: employeeDataSource,
              allowFiltering: true,
              selectionMode: SelectionMode.multiple,
              columnWidthMode: ColumnWidthMode.fill,
              onSelectionChanged: (addedRows, removedRows) {
                // Add rows if not already in selectedRows.
                selectedRows.addAll(
                  addedRows.where((row) => !selectedRows.contains(row)),
                );

                // Remove rows if they exist in selectedRows.
                selectedRows.removeWhere((row) => removedRows.contains(row));
              },
              columns: <GridColumn>[
                GridColumn(
                  columnName: 'id',
                  label: Container(
                    padding: const EdgeInsets.all(16.0),
                    alignment: Alignment.center,
                    child: const Text('ID'),
                  ),
                ),
                GridColumn(
                  columnName: 'name',
                  label: Container(
                    padding: const EdgeInsets.all(8.0),
                    alignment: Alignment.center,
                    child: const Text('Name'),
                  ),
                ),
                GridColumn(
                  columnName: 'designation',
                  label: Container(
                    padding: const EdgeInsets.all(8.0),
                    alignment: Alignment.center,
                    child: const Text(
                      'Designation',
                      overflow: TextOverflow.ellipsis,
                    ),
                  ),
                ),
                GridColumn(
                  columnName: 'salary',
                  label: Container(
                    padding: const EdgeInsets.all(8.0),
                    alignment: Alignment.center,
                    child: const Text('Salary'),
                  ),
                ),
              ],
            ),
          ),
        ],
      ),
    );
  }

You can download this example on GitHub.