Added new kb article dropdownlist-sorting-numerically-by-value (#686)

Co-authored-by: KB Bot <[email protected]>

Author: github-actions[bot]

knowledge-base/dropdownlist-sorting-numerically-by-value.md

@@ -0,0 +1,85 @@
+---
+title: Sorting RadDropDownList Numerically by Value
+description: Learn how to sort items in a RadDropDownList numerically by their values using code-behind logic in ASP.NET AJAX.
+type: how-to
+page_title: Sorting RadDropDownList Items by Numeric Value in ASP.NET AJAX
+slug: dropdownlist-sorting-numerically-by-value
+tags: asp.net ajax, dropdownlist, sorting, numeric, code-behind
+res_type: kb
+ticketid: 1686740
+---
+
+## Environment
+
+<table>
+<tbody>
+<tr>
+<td>Product</td>
+<td>RadDropDownList for ASP.NET AJAX</td>
+</tr>
+<tr>
+<td>Version</td>
+<td>All</td>
+</tr>
+</tbody>
+</table>
+
+## Description
+
+I want to sort the items of a [RadDropDownList](https://docs.telerik.com/devtools/aspnet-ajax/controls/dropdownlist/overview) numerically based on their `Value` property instead of the `Text` property. By default, the control sorts items by `Text`. Is there a way to sort the RadDropDownList by numeric values programmatically?
+
+This knowledge base article also answers the following questions:
+
+- How can I sort RadDropDownList items by value in ASP.NET AJAX?
+- Is it possible to perform numeric sorting on RadDropDownList?
+- How to sort RadDropDownList using code-behind?
+
+## Solution
+
+To sort the RadDropDownList items numerically by their `Value`, you can perform custom sorting in the code-behind. The following example demonstrates how to achieve this:
+
+### Code Example
+
+````
+protected void Page_Load(object sender, EventArgs e)
+{
+    if (!IsPostBack)
+    {
+        // Define RadDropDownList items
+        List<DropDownListItem> tourItems = new List<DropDownListItem>
+        {
+            new DropDownListItem("Alps Tour", "100"),
+            new DropDownListItem("Desert Safari", "25"),
+            new DropDownListItem("Island Escape", "7"),
+            new DropDownListItem("Mountain Hike", "50"),
+            new DropDownListItem("City Lights", "300")
+        };
+
+        // Sort by Value numerically
+        List<DropDownListItem> sortedItems = tourItems.OrderBy(item => int.Parse(item.Value)).ToList();
+
+        // Clear existing items and add sorted items
+        RadDropDownList1.Items.Clear();
+        foreach (DropDownListItem item in sortedItems)
+        {
+            RadDropDownList1.Items.Add(item);
+        }
+    }
+}
+````
+
+Explanation
+
+1. **Sorting Items**: The code uses LINQ to sort the items based on their numeric `Value`. The `int.Parse` method is used to ensure the sorting is numerical rather than alphabetical.
+2. **Re-adding Items**: After sorting, the existing items are cleared using `RadDropDownList1.Items.Clear()`. The sorted items are then added back to the control.
+
+Notes
+
+- Ensure that all `Value` properties can be parsed into integers. If the values are non-integer, adjust the parsing logic accordingly.
+- This approach is ideal when you need to customize sorting behavior for RadDropDownList items.
+
+## See Also
+
+- [RadDropDownList Overview](https://docs.telerik.com/devtools/aspnet-ajax/controls/dropdownlist/overview)
+- [RadComboBox vs RadDropDownList](https://docs.telerik.com/devtools/aspnet-ajax/controls/dropdownlist/dropdownlist-vs-radcombobox)
+- [Sorting Items in RadComboBox](https://docs.telerik.com/devtools/aspnet-ajax/controls/combobox/overview)