Merge pull request #3 from SweathaBharathi/patch-1

Update README.md

Author: vijayarasan

README.md

@@ -1,4 +1,100 @@
-# How-to-restrict-drag-and-drop-of-nodes-in-WPF-TreeViewAdv
-This session explains how to restrict drag and drop of nodes in WPF TreeViewAdv.
+# How to restrict drag and drop of parent node into another parent node in WPF TreeViewAdv?
 
-KB article - [How-to-restrict-drag-and-drop-of-nodes-in-WPF-TreeViewAdv](https://www.syncfusion.com/kb/11652/how-to-restrict-drag-and-drop-of-parent-node-into-another-parent-node-in-wpf-treeviewadv)
+This article will explain how to restrict drag and drop of a parent node into another parent node, where it will allow only reordering the child nodes in [WPF TreeViewAdv](https://help.syncfusion.com/wpf/classic/treeview/overview). This can be achieved by using [DragStart](https://help.syncfusion.com/cr/wpf/Syncfusion.Windows.Tools.Controls.TreeViewAdv.html#Syncfusion_Windows_Tools_Controls_TreeViewAdv_DragStart) and [DragEnd](https://help.syncfusion.com/cr/wpf/Syncfusion.Windows.Tools.Controls.TreeViewAdv.html#Syncfusion_Windows_Tools_Controls_TreeViewAdv_DragEnd) event.
+
+```csharp
+public class Model
+{
+    public Model()
+    {
+        SubItems = new ObservableCollection<Model>();
+    }
+
+    public string Header { get; set; }
+    public ObservableCollection<Model> SubItems { get; set; }
+}
+```
+
+```csharp
+public class ViewModel
+{
+    public ViewModel()
+    {
+        TreeItems = new ObservableCollection<Model>();
+        PopulateData();
+    }
+
+    public ObservableCollection<Model> TreeItems { get; set; }
+
+    private void PopulateData()
+    {
+        Model root1 = new Model() { Header = "Root1" };
+        PopulateSubItems(root1);
+        TreeItems.Add(root1);
+
+        Model root2 = new Model() { Header = "Root2" };
+        PopulateSubItems(root2);
+        TreeItems.Add(root2);
+
+        Model root3 = new Model() { Header = "Root3" };
+        PopulateSubItems(root3);
+        TreeItems.Add(root3);
+    }
+
+    private void PopulateSubItems(Model root)
+    {
+        Model subItem1 = new Model() { Header = "Item1" };
+        Model subItem2 = new Model() { Header = "Item2" };
+        Model subItem3 = new Model() { Header = "Item3" };
+        Model subItem4 = new Model() { Header = "Item4" };
+
+        root.SubItems.Add(subItem1);
+        root.SubItems.Add(subItem2);
+        root.SubItems.Add(subItem3);
+        root.SubItems.Add(subItem4);
+    }
+}
+```
+
+```xml
+<Grid>
+    <syncfusion:TreeViewAdv Margin="10"
+                            x:Name="tree"
+                            AllowDragDrop="True"
+                            ItemsSource="{Binding TreeItems}">
+        <syncfusion:TreeViewAdv.ItemTemplate>
+            <HierarchicalDataTemplate ItemsSource="{Binding SubItems}">
+                <TextBlock Text="{Binding Header}" />
+            </HierarchicalDataTemplate>
+        </syncfusion:TreeViewAdv.ItemTemplate>
+    </syncfusion:TreeViewAdv>
+</Grid>
+```
+
+```csharp
+public partial class MainWindow : Window
+{
+    TreeViewItemAdv drag = null;
+
+    public MainWindow()
+    {
+        InitializeComponent();
+    }
+
+    public void DragStart(object sender, DragTreeViewItemAdvEventArgs e)
+    {
+        drag = (sender as TreeViewAdv).SelectedContainer;
+    }
+
+    public void DragEnd(object sender, DragTreeViewItemAdvEventArgs e)
+    {
+        e.Cancel = false;
+        TreeViewItemAdv drop = e.TargetDropItem as TreeViewItemAdv;
+
+        if (drag != null && drop != null && drag.ParentItemsControl == drop.ParentItemsControl)
+        {
+            e.Cancel = true;
+        }
+    }
+}
+```