How to sort ASP.NET DropDownList based on DataValueField or DataTextField using LINQ?

Sorting ASP.NET Dropdown list is very common requirement for any of the web application development.  To Implement this features sometimes developers used to iterate through each and every item and create a sorted list of element then reassign the same source to dropdownlist or sort the element at source itself. But this thing can be done easily using LINQ. In this post I am going describe how you can sort a ASP.NET DropDownList based on either of DataTextField or DataValueField using LINQ and list of KeyValuePair elements as DataSource.

To start with the application, let’s consider you have following List of employee data as datasource of the DropDownList.

 /// <summary>
 /// Create List Of Employee
 /// </summary>
 List<KeyValuePair<int, string>> employees = new List<KeyValuePair<int, string>>
        {        new KeyValuePair<int,string>(1,"Abhijit"),
                  new KeyValuePair<int,string>(2,"Rahul"),
                  new KeyValuePair<int,string>(3,"Kunal"),
                  new KeyValuePair<int,string>(4,"Atul"),
                 new KeyValuePair<int,string>(5,"Abhishek"),

In the employee list collection, you have added KeyValuePair for each element, where Key is employee ID and Value is the employee name.  The most interesting part of using KeyValuePair is you can bind either of Key or Value with the DropDownList as per your requirement

Now let’s bind the DropDownList with the DataSource