Bind Enum constants to Dropdown control in ASP.NET

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The following extension method is used to bind enumerated constants to any ListControls (DropdownList, ListBox etc) in ASP.NET:


using System;

using System.ComponentModel.DataAnnotations;
using System.Linq;
using System.Web.UI.WebControls;

public static class ListControlExtension{
    public static void BindEnum(this ListControl listControl,
                                Type enumType) 
        {
       string caption;
       string value;
       object[] objArray;

       foreach (var enumValue in Enum.GetValues(enumType))    
               {
           // Get the numeric value of enum member
                value = ((int)enumValue).ToString(); 

           // Get the DisplayAttribute object of enum member
           objArray = enumType.GetField(enumValue.ToString())
                            .GetCustomAttributes(typeof(DisplayAttribute),
                            false);            

         // If Display attribute is not specified
          if (objArray.Count() == 0) 
          {
             // just take the enum member text         
             caption = enumValue.ToString(); 
          }
          else         
          {
             // take the DisplayAttribute name of enum member
             caption = ((DisplayAttribute)objArray.Single()).GetName();            
      }

          listControl.Items.Add(new ListItem(caption, value));
                      objArray =  null;
            }
       }
}

For example, the following Enum constant,

public enum EmploymentStatus{
    Active,
    Resigned,
    Retired,
    [Display(Name = "Unpaid Long Leave")]
    LongLeave,
         [Display(Name = "Paid Long Leave")] 
    Sabbatical
}

can be bound to a Dropdown control as

     
        ddlDefectStatus.BindEnum(typeof(EmploymentStatus));


Note that the extension method binds the Display attribute's Name property value (if it is provided) to the list control.

The Display attribute is helpful when you want to show a  text other than the enum text. For example, 'Unpaid Long Leave' and 'Paid Long Leave' are shown in the list control instead of LongLeave and Sabbatical respectively.

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