ListBoxItemCollection.AddEnum<TEnum>(Converter<TEnum, String>, Boolean) Method

Adds new items that represent elements of the specified enumeration to the control. Allows you to customize item descriptions and specify whether underlying integer values are assigned to the item values.

Namespace: DevExpress.XtraEditors.Controls

Assembly: DevExpress.XtraEditors.v24.2.dll

Declaration

C#

public void AddEnum<TEnum>(
    Converter<TEnum, string> displayTextConverter,
    bool addEnumeratorIntegerValues
)

VB.NET

Public Sub AddEnum(Of TEnum)(
    displayTextConverter As Converter(Of TEnum, String),
    addEnumeratorIntegerValues As Boolean
)

Parameters

Name	Type	Description
displayTextConverter	Converter<TEnum, String>	A System.Converter delegate that generates item descriptions to be displayed.
addEnumeratorIntegerValues	Boolean	true, if values for generated items should store numeric enumerator values; false, if these values should store constant enumerator names instead.

Type Parameters

Name	Description
TEnum	The type of the required enumeration.

Remarks

This method fetches elements from the specified enumeration and stores them as ListBoxItem objects within the ListBoxItemCollection. The ListBoxControl bound to this collection displays the items according to settings passed as the method’s parameters:

• addEnumeratorIntegerValues

  Each ListBoxItem generated from the enumeration’s element has the Value property. Some descendants also have the Description property. When you populate an editor from an enumeration, the Description and Value properties are both assigned the enumeration text values. If the addEnumeratorIntegerValues parameter is set to true, the items’ Value properties store integer constants related to enumeration elements, and Description properties - the enumeration elements’ text values.

• displayTextConverter This parameter allows you to specify a delegate that encapsulates a method which modifies item descriptions the users see. Note that you can do the same thing by declaring Description attributes before enumeration values as shown below.

  C#

  public enum Actions {
      Add = 2,
      Remove = 4,
      New = 8,
      Save = 16,
      [Description("Save All")]
      SaveAll = 32,
      None
  }
  

  VB.NET

  Public Enum Actions
      Add = 2
      Remove = 4
      [New] = 8
      Save = 16
      <Description("Save All")>
      SaveAll = 32
      None
  End Enum
  

Example

The example below demonstrates how to populate the ListBoxControl‘s ListBoxItemCollection with items from the specified enum.

C#

using System;
using System.ComponentModel;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public enum Day {
        // The Description attribute can be used
        // to provide descriptions for items.
        [Description("Saturday")]
        Sat = 7,
        Sun = 1,
        Mon,
        Tue,
        Wed,
        Thu,
        Fri
    };
    public partial class Form1 : DevExpress.XtraEditors.XtraForm {
        public Form1() {
            InitializeComponent();
            listBoxControl1.Items.AddEnum<Day>(new Converter<Day, string>(MyConverter), false);
        }

        // Returns a custom string based on the specified day.
        public static string MyConverter(Day d) {
            Type dayType = d.GetType();
            Type dayUnderlyingType = Enum.GetUnderlyingType(dayType);
            return Convert.ChangeType(d, dayUnderlyingType).ToString() + ". " + d.ToString();
        }
    } 
}

VB.NET

Imports System
Imports System.ComponentModel
Imports System.Windows.Forms

Namespace WindowsFormsApplication1
    Public Enum Day
        ' The Description attribute can be used
        ' to provide descriptions for items.
        <Description("Saturday")>
        Sat = 7
        Sun = 1
        Mon
        Tue
        Wed
        Thu
        Fri
    End Enum
    Partial Public Class Form1
        Inherits DevExpress.XtraEditors.XtraForm

        Public Sub New()
            InitializeComponent()
            listBoxControl1.Items.AddEnum(Of Day)(New Converter(Of Day, String)(AddressOf MyConverter), False)
        End Sub

        ' Returns a custom string based on the specified day.
        Public Shared Function MyConverter(ByVal d As Day) As String
            Dim dayType As Type = d.GetType()
            Dim dayUnderlyingType As Type = System.Enum.GetUnderlyingType(dayType)
            Return Convert.ChangeType(d, dayUnderlyingType).ToString() & ". " & d.ToString()
        End Function
    End Class
End Namespace