can i freeze the First top row of datagrid in wpf ?

it’s a common confusion point in WPF DataGrid, because while you can easily freeze columns (using FrozenColumnCount), freezing rows isn’t natively supported out-of-the-box in WPF’s DataGrid.

Let’s break this down clearly

Problem

You want to:

• Keep the built-in column headers (already frozen ),

• AND freeze one more custom top row (like a secondary header or summary row)
  — so that this row stays visible even when scrolling vertically.

Limitation

In WPF’s DataGrid, there is no direct property like FrozenRowCount.
You can only freeze columns, not rows.

But — we can achieve the same effect with a UI layout trick.

Workaround: Use Two DataGrids in a Grid Layout

You can place two DataGrids (or one DataGrid + one Grid) —
the top one for your "frozen row", and the bottom one scrollable.

Example

Explanation:

• The top DataGrid (or even a simple Grid or StackPanel) holds the “frozen” top row data.

• The bottom DataGrid scrolls normally.

• The two can have identical columns to appear seamless.

• To make them scroll horizontally together, you can synchronize the scrollbars via event binding in code-behind.

Optional Enhancement – Sync Horizontal Scroll

In code-behind:

private void MainDataGrid_ScrollChanged(object sender, ScrollChangedEventArgs e)
{
    if (e.HorizontalChange != 0)
    {
        FrozenDataGrid.ScrollViewer.ScrollToHorizontalOffset(e.HorizontalOffset);
    }
}

You’d need to get the internal ScrollViewer of each DataGrid (can use VisualTreeHelper).

Alternative Approach – Use a Custom Template

If you really want everything in a single DataGrid, you can define a frozen summary row in the DataGrid’s template (via a Grid overlay), but that’s complex and doesn’t work well with virtualization or scrolling.

So the two-DataGrid layout is the most reliable, professional way.

Summary