How to select the rows based on a cell value in WinUI DataGrid SfDataGrid

You can select the rows based on cell value by adding corresponding records to SelectedItems in WinUI DataGrid (SfDataGrid). You can get the cell value of the particular cell using GetPropertyAccessprovider method in SfDataGrid.View, as shown in the following code example.

private void btnSelectRowClicked(object sender, RoutedEventArgs e)
{
    if (dataGrid.View != null)
    {
        reflector = dataGrid.View.GetPropertyAccessProvider();

        if (reflector != null)
        {
            // Check the DataGrid has rows and columns.
            if (dataGrid.View.Records != null && dataGrid.Columns != null)
            {
                // Clear the previously selected items in SfDataGrid
                dataGrid.SelectedItems.Clear();

                // Get the total number of rows in the DataGrid.
                var totalRowIndex = dataGrid.View.Records.Count;

                // Get the total number of columns in the DataGrid.
                var totalColumnIndex = dataGrid.Columns.Count;

                // Iterate the rows.
                for (int recordIndex = 0; recordIndex < totalRowIndex; recordIndex++)
                {
                    // Iterate the columns.
                    for (int colindex = 0; colindex < totalColumnIndex; colindex++)
                    {
                        // Get the record based on recordIndex.
                        var record = this.dataGrid.View.Records[recordIndex];

                        if (record != null)
                        {
                            // Get the mappingName of the column.
                            var mappingName = dataGrid.Columns[colindex].MappingName;

                            if (mappingName != null)
                            {
                                //Get the cell value based on mappingName.
                                var currentCellValue = reflector.GetValue(record.Data, mappingName);

                                // Check the cell value is equal to "Germany".
                                if (currentCellValue != null && currentCellValue.ToString() == "Germany")
                                {
                                    // Get the record entry based on recordIndex that satisfied the condition.
                                    RecordEntry item = dataGrid.View.Records[recordIndex];

                                    if (item != null && dataGrid.SelectedItems != null)
                                    {
                                        //selected rows should be added here.
                                        dataGrid.SelectedItems.Add(item.Data);
                                    }
                                }
                            }
                        }
                    }
                }
            }
        }
    }
}

Take a moment to peruse the WinUI DataGrid - Selection documentation, to learn more about selection with code examples.