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

Author: SreemonPremkumarM

README.md

@@ -1,2 +1,38 @@
-# How to hide the detailsview expander icon based on child records count in winui datagrid?
-This example describes how to hide the detailsview expander icon based on child records count in winui datagrid.
+# How to hide the detailsview expander icon based on child records count in WinUI DataGrid
+
+This example describes how to hide the detailsview expander icon based on child records count in [WinUI DataGrid](https://www.syncfusion.com/winui-controls/datagrid) (SfDataGrid).
+
+By default, the state of expander icon is visible for all the data rows in parent DataGrid even if its `RelationalColumn` property has an empty collection or null.
+
+You can customize hiding the details view expander icon by handling the `SfDataGrid.QueryDetailsViewExpanderState` event. This event occurs when expander icon is changed on expanding or collapsing the details view. You can hide the expander icon by setting the `ExpanderVisibility` property to `false` in the `SfDataGrid.QueryDetailsViewExpanderState` event based on condition.
+
+``` csharp
+dataGrid.DetailsViewExpanding += DataGrid_DetailsViewExpanding;
+dataGrid.QueryDetailsViewExpanderState += DataGrid_QueryDetailsViewExpanderState;
+
+private void DataGrid_DetailsViewExpanding(object sender, GridDetailsViewExpandingEventArgs e)
+{
+    var employeeInfo = e.Record as Employee;
+    if (employeeInfo != null)
+    {
+        if (employeeInfo.Sales.Count == 0)
+            e.Cancel = true;
+    }
+}
+
+private void DataGrid_QueryDetailsViewExpanderState(object sender, QueryDetailsViewExpanderStateEventArgs e)
+{
+    var employeeInfo = e.Record as Employee;
+    if (employeeInfo != null)
+    {
+        if (employeeInfo.Sales.Count == 0)
+        {
+            e.ExpanderVisibility = false;
+        }
+    }
+}
+```
+
+The following screenshot illustrates hiding expander icon state based on child items count.
+
+![hide the detailsview expander](hide_the_detailsview_expander_icon.png)