Merge pull request #2 from SyncfusionExamples/WF-64663-Index-ComboBox

WF-64663-Updated README.md file.

Author: Manivannan-E

README.md

@@ -1,2 +1,73 @@
-# How-to-select-the-item-through-index-in-WF-SfComboBox
-This respository contains the sample that how to select the item through index in WF SfComboBox control.
+# How to Select an Item by Index in WinForms SfComboBox
+This example demonstrates how to select an item programmatically by index in the Syncfusion WinForms SfComboBox control. The SfComboBox supports both index-based selection and object-based selection, making it flexible for scenarios like applying default selections, loading saved preferences, or responding to application logic.
+
+## Why This Is Useful
+- **Dynamic Selection**: Automatically select items based on conditions.
+- **Improved UX**: Pre-load user preferences or defaults.
+- **Flexibility**: Choose items by index or by object reference.
+
+## Key Properties
+- **SelectedIndex**: Sets or gets the zero-based index of the selected item.
+- **SelectedItem**: Sets or gets the actual object from the data source.
+
+## Example Code
+```C#
+
+public Form1()
+{
+    InitializeComponent();
+
+    // Sample data
+    List<State> list = GetData();
+
+    // Create and configure SfComboBox
+    SfComboBox sfComboBox1 = new SfComboBox
+    {
+        Size = new Size(150, 28),
+        Location = new Point(138, 56),
+        DataSource = list,
+        DisplayMember = "DispValue",
+        ValueMember = "SfValue",
+        ComboBoxMode = Syncfusion.WinForms.ListView.Enums.ComboBoxMode.SingleSelection,
+        AutoCompleteMode = AutoCompleteMode.SuggestAppend,
+        AutoCompleteSuggestMode = Syncfusion.WinForms.ListView.Enums.AutoCompleteSuggestMode.Contains,
+        MaxDropDownItems = 10
+    };
+
+    // Select the item based on index (second item)
+    sfComboBox1.SelectedIndex = 1;
+
+    // Select the item based on object
+    sfComboBox1.SelectedItem = list[1];
+
+    this.Controls.Add(sfComboBox1);
+}
+
+private List<State> GetData()
+{
+    return new List<State>
+    {
+        new State { DispValue = "California", SfValue = 1 },
+        new State { DispValue = "Texas", SfValue = 2 },
+        new State { DispValue = "Florida", SfValue = 3 }
+    };
+}
+
+public class State
+{
+    public string DispValue { get; set; }
+    public int SfValue { get; set; }
+}
+```
+
+## Notes
+- Use SelectedIndex for index-based selection (zero-based).
+- Use SelectedItem for object-based selection.
+- Ensure the data source is bound before setting these properties.
+
+## Reference
+For more details, refer to the official Syncfusion Knowledge Base: https://support.syncfusion.com/kb/article/10653/how-to-select-the-item-through-index-in-winforms-sfcombobox
+
+## Output
+![Select item through index in WinForms SfComboBox](index_selection_in_winforms_sfcombobox.png)
+