How to get the reference of the control added inside the DataTemplate of the GridTemplateColumn in WPF DataGrid (SfDataGrid)?

private void OnButton_Click(object sender, RoutedEventArgs e)
{
    var columnElement = this.dataGrid.SelectionController.CurrentCellManager.CurrentCell.ColumnElement as GridCell;
    var dataColumn = columnElement.ColumnBase as Syncfusion.UI.Xaml.Grid.DataColumn;
    if (dataColumn.Renderer.GetType() == typeof(GridCellTemplateRenderer))
    {
        ContentPresenter contentPresenter = this.FindVisualChild<ContentPresenter>(columnElement);
 
        var TextBox = GetVisualChild<TextBox>(contentPresenter);
    }
}
 
private T GetVisualChild<T>(DependencyObject parent) where T : Visual
{
    T child = default(T);
    int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
    for (int i = 0; i < numVisuals; i++)
    {
        Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
        child = v as T;
        if (child == null)
        {
            child = GetVisualChild<T>(v);
        }
        if (child != null)
        {
            break;
        }
    }
    return child;
}
public childItem FindVisualChild<childItem>(DependencyObject obj) where childItem : DependencyObject
{
    for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
    {
        DependencyObject child = VisualTreeHelper.GetChild(obj, i);
        if (child != null && child is childItem)
            return (childItem)child;
        else
        {
            childItem childOfChild = FindVisualChild<childItem>(child);
            if (childOfChild != null)
                return childOfChild;
        }
    }
    return null;
}