Merge pull request #644 from telerik/new-kb-prevent-column-drag-over-…

…pinned-radgridview-winforms-e15c72f0216146808edb804998f45c41

Added new kb article prevent-column-drag-over-pinned-radgridview-winforms

knowledge-base/prevent-column-drag-over-pinned-radgridview-winforms.md

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+---
+title: Prevent Column Dragging Over Pinned Columns in RadGridView for WinForms
+description: Learn how to restrict the reordering of RadGridView columns by preventing columns from being dragged over pinned columns.
+type: how-to
+page_title: How to Restrict Column Dragging Over Pinned Columns in RadGridView for WinForms
+slug: gridview-prevent-column-drag-over-pinned
+tags: gridview, winforms, drag-and-drop, pinned-columns, radgriddragdropservice
+res_type: kb
+ticketid: 1667283
+---
+
+## Environment
+
+|Product Version|Product|Author|
+|----|----|----|
+|2024.3.924|RadGridView for WinForms|[Nadya Todorova](https://www.telerik.com/blogs/author/nadya-karaivanova)|
+
+## Description
+
+When working with pinned columns in RadGridView, the client may want to prevent dragging unpinned columns over or between the pinned columns. Currently, unpinned column can be moved and placed between pinned columns, effectively increasing the number of pinned columns. 
+
+## Solution
+
+To achieve the desired behavior, leverage the [RadDragDropService](https://docs.telerik.com/devtools/winforms/controls/gridview/drag-and-drop/radgridviewdragdropservice) of RadGridView, which handles the drag-and-drop operations. By handling the `PreviewDragOver` event, you can prevent a column from being dropped over a pinned column.
+
+Follow these steps to implement the solution:
+
+````C#
+// Access the RadDragDropService
+RadDragDropService svc = this.radGridView1.GridViewElement.GetService<RadDragDropService>();
+
+// Subscribe to the PreviewDragOver event
+svc.PreviewDragOver += svc_PreviewDragOver;
+
+// Event handler to prevent dropping over pinned columns
+private void svc_PreviewDragOver(object sender, RadDragOverEventArgs e)
+{
+    if (e.HitTarget is GridHeaderCellElement)
+    {
+        GridHeaderCellElement headerCell = e.HitTarget as GridHeaderCellElement;
+        if (headerCell.ColumnInfo.IsPinned)
+        {
+            // Prevent dropping over pinned columns
+            e.CanDrop = false;
+        }
+    }
+}
+
+````
+
+## See Also
+
+- [RadGridView for WinForms Documentation - Drag and Drop](https://docs.telerik.com/devtools/winforms/controls/gridview/drag-and-drop/radgridviewdragdropservice)
+- [RadGridView for WinForms Documentation - Pinned Columns](https://docs.telerik.com/devtools/winforms/controls/gridview/columns/pinned-columns)