WF-64705 - Updated the README file

README.md

@@ -1,2 +1,45 @@
-# How to differentiate combobox column from other columns in non-editable in view in winforms datagrid?
-This example illustrates how to differentiate combobox column from other columns in non-editable in view in winforms datagrid
+# How to differentiate combobox column from other columns in non-editable display mode in WinForms DataGrid (SfDataGrid) 
+
+## Differentiate combobox column from other columns
+
+Normally, the drop-down arrow for [GridComboBoxColumn](https://help.syncfusion.com/cr/wpf/Syncfusion.UI.Xaml.Grid.GridComboBoxColumn.html) will be shown only in the edit mode. You can differentiate the combo box column from other columns by showing the drop-down arrow in the display mode by creating custom renderer for the combo box column.
+
+## C#
+
+```C#
+public Form1()
+{
+    InitializeComponent();
+    this.sfDataGrid1.CellRenderers["ComboBox"] = new CustomComboBoxCellRenderer();
+}
+
+public class CustomComboBoxCellRenderer : GridComboBoxCellRenderer
+{
+    protected override void OnRender(Graphics paint, Rectangle cellRect, string cellValue, CellStyleInfo style, DataColumnBase column, Syncfusion.WinForms.GridCommon.ScrollAxis.RowColumnIndex rowColumnIndex)
+    {
+        base.OnRender(paint, cellRect, cellValue, style, column, rowColumnIndex);
+        var dropDownbuttonRect = new Rectangle(cellRect.X + cellRect.Width - 17, cellRect.Y + (cellRect.Height / 2), 8, 4);
+        paint.DrawLine(new Pen(Color.Gray), dropDownbuttonRect.X, dropDownbuttonRect.Y, dropDownbuttonRect.X + (dropDownbuttonRect.Width / 2), dropDownbuttonRect.Y + dropDownbuttonRect.Height);
+        paint.DrawLine(new Pen(Color.Gray), dropDownbuttonRect.X + dropDownbuttonRect.Width, dropDownbuttonRect.Y, dropDownbuttonRect.X + (dropDownbuttonRect.Width / 2), dropDownbuttonRect.Y + dropDownbuttonRect.Height);
+    }
+}
+```
+
+## VB
+
+```VB
+Public Sub New()
+    InitializeComponent()
+    Me.sfDataGrid1.CellRenderers("ComboBox") = New CustomComboBoxCellRenderer()
+End Sub
+
+Public Class CustomComboBoxCellRenderer
+    Inherits GridComboBoxCellRenderer
+    Protected Overrides Sub OnRender(ByVal paint As Graphics, ByVal cellRect As Rectangle, ByVal cellValue As String, ByVal style As CellStyleInfo, ByVal column As DataColumnBase, ByVal rowColumnIndex As Syncfusion.WinForms.GridCommon.ScrollAxis.RowColumnIndex)
+        MyBase.OnRender(paint, cellRect, cellValue, style, column, rowColumnIndex)
+        Dim dropDownbuttonRect = New Rectangle(cellRect.X + cellRect.Width - 17, cellRect.Y + (cellRect.Height \ 2), 8, 4)
+        paint.DrawLine(New Pen(Color.Gray), dropDownbuttonRect.X, dropDownbuttonRect.Y, dropDownbuttonRect.X + (dropDownbuttonRect.Width \ 2), dropDownbuttonRect.Y + dropDownbuttonRect.Height)
+        paint.DrawLine(New Pen(Color.Gray), dropDownbuttonRect.X + dropDownbuttonRect.Width, dropDownbuttonRect.Y, dropDownbuttonRect.X + (dropDownbuttonRect.Width \ 2), dropDownbuttonRect.Y + dropDownbuttonRect.Height)
+    End Sub
+End Class
+```