ES-975464 - Resolve the ReadMe file length issue in this sample repository

Author: SreemonPremkumarM

README.md

@@ -1,2 +1,41 @@
-# how-to-programmatically-expand-an-item-in-wpf-treeview-treeviewadv-
-This sample shows how to programmatically expand an item in wpf treeview (treeviewadv).
+# How to programmatically expand an item in WPF TreeViewAdv
+
+This sample shows how to programmatically expand an item in [WPF TreeView](https://help.syncfusion.com/wpf/classic/treeview/overview) (TreeViewAdv).
+
+`TreeViewAdv` allows to expand or collapse each node by setting [IsExpanded](https://help.syncfusion.com/cr/wpf/Syncfusion.Windows.Tools.Controls.TreeViewItemAdv.html#Syncfusion_Windows_Tools_Controls_TreeViewItemAdv_IsExpanded) property.
+
+``` csharp
+public MainWindow()
+{
+    InitializeComponent();
+    TreeViewAdv treeViewAdv = new TreeViewAdv();
+    TreeViewItemAdv root1 = new TreeViewItemAdv() { Header = "Marital Status" };
+    TreeViewItemAdv subitem11 = new TreeViewItemAdv() { Header = "Single" };
+    TreeViewItemAdv subitem12 = new TreeViewItemAdv() { Header = "Married" };
+    TreeViewItemAdv subitem13 = new TreeViewItemAdv() { Header = "Married with Children" };
+
+    root1.Items.Add(subitem11);
+    root1.Items.Add(subitem12);
+    root1.Items.Add(subitem13);
+
+    TreeViewItemAdv root2 = new TreeViewItemAdv() { Header = "Baby Vaccines" };
+    TreeViewItemAdv subitem21 = new TreeViewItemAdv() { Header = "Hepatitis B" };
+    TreeViewItemAdv subitem22 = new TreeViewItemAdv() { Header = "Tetanus" };
+    TreeViewItemAdv subitem23 = new TreeViewItemAdv() { Header = "Polio" };
+    TreeViewItemAdv subitem24 = new TreeViewItemAdv() { Header = "Measles" };
+
+    root2.Items.Add(subitem21);
+    root2.Items.Add(subitem22);
+    root2.Items.Add(subitem23);
+    root2.Items.Add(subitem24);
+
+    TreeViewItemAdv root3 = new TreeViewItemAdv() { Header = "Baby Vaccines" };
+
+    treeViewAdv.Items.Add(root1);
+    treeViewAdv.Items.Add(root2);
+    treeViewAdv.Items.Add(root3);
+    Grid.Children.Add(treeViewAdv);
+
+    root1.IsExpanded = true;
+}
+```