The ListControl looks exactly like the old ListBox, but it has better performance and fully supports virtualization.
I have prepared a small proof of concept that creates a label and two images for a list Item,
namespace RadListControlCustomItems
{
using System;
using System.ComponentModel;
using System.Drawing;
using System.Windows.Forms;
using Telerik.WinControls;
using Telerik.WinControls.Enumerations;
using Telerik.WinControls.Layouts;
using Telerik.WinControls.Primitives;
using Telerik.WinControls.UI;
public partial class Form1 : Form
{
private RadListControl radListControl1;
public Form1()
{
InitializeComponent();
this.radListControl1 = new RadListControl();
this.Size = new Size(500, 300);
this.Load += new System.EventHandler(Form1_Load);
}
void Form1_Load(object sender, System.EventArgs e)
{
radListControl1.Dock = DockStyle.Fill;
this.radListControl1.CreatingVisualListItem += CreatingVisualListItem;
this.radListControl1.ItemDataBinding += this.ItemDataBinding;
this.radListControl1.ItemDataBound += this.ItemDataBound;
this.Controls.Add(radListControl1);
PrepareDataSourceAndShowDropDown(1000);
}
private void PrepareDataSourceAndShowDropDown(int noObjects)
{
this.radListControl1.DataSource = null;
this.radListControl1.DisplayMember = "Name";
BindingList<BussinessObject> list = new BindingList<BussinessObject>();
for (int i = 0; i < noObjects; ++i)
{
BussinessObject businessObject = new BussinessObject();
businessObject.Image = Properties.Resources.combobox;
businessObject.Image2 = i % 2 == 0 ? Properties.Resources.calendar : null;
businessObject.Name = " Item " + (i + 1);
list.Add(businessObject);
}
this.radListControl1.DataSource = list;
}
#region Event Handlers
private void ItemDataBound(object sender, ListItemDataBoundEventArgs args)
{
CustomListDataItem listDataItem = (CustomListDataItem)args.NewItem;
BussinessObject dataObject = (BussinessObject)listDataItem.DataBoundItem;
listDataItem.Name = dataObject.Name;
listDataItem.Image = dataObject.Image;
listDataItem.Image2 = dataObject.Image2;
}
private void ItemDataBinding(object sender, ListItemDataBindingEventArgs args)
{
args.NewItem = new CustomListDataItem();
}
private void CreatingVisualListItem(object sender, CreatingVisualListItemEventArgs args)
{
args.VisualItem = new CustomListVisualItem();
}
#endregion Event Handlers
#region Overrides
#endregion Overrides
}
public class BussinessObject : INotifyPropertyChanged
{
#region Fields
private string name;
private Image image;
private Image image2;
#endregion Fields
#region Properties
public string Name
{
get
{
return name;
}
set
{
if (this.name == value)
{
return;
}
this.name = value;
this.OnNotifyPropertyChanged("Name");
}
}
public Image Image
{
get
{
return this.image;
}
set
{
if (this.image == value)
{
return;
}
this.image = value;
this.OnNotifyPropertyChanged("Image");
}
}
public Image Image2
{
get
{
return this.image2;
}
set
{
if (this.image2 == value)
{
return;
}
this.image2 = value;
this.OnNotifyPropertyChanged("Image2");
}
}
#endregion Properties
#region INotifyPropertyChanged Implementation
public event PropertyChangedEventHandler PropertyChanged;
private void OnNotifyPropertyChanged(string property)
{
if (this.PropertyChanged != null)
{
this.PropertyChanged(this, new PropertyChangedEventArgs(property));
}
}
#endregion INotifyPropertyChanged Implementation
}
public class CustomListDataItem : RadListDataItem
{
#region RadProperties
public static readonly RadProperty ImageProperty = RadProperty.Register("Image", typeof(Image), typeof(CustomListDataItem), new RadElementPropertyMetadata(null));
public static readonly RadProperty Image2Property = RadProperty.Register("Image2", typeof(Image), typeof(CustomListDataItem), new RadElementPropertyMetadata(null));
public static readonly RadProperty NameProperty = RadProperty.Register("Name", typeof(string), typeof(CustomListDataItem), new RadElementPropertyMetadata(""));
#endregion RadProperties
#region Properties
public new Image Image
{
get
{
return (Image)this.GetValue(CustomListDataItem.ImageProperty);
}
set
{
this.SetValue(CustomListDataItem.ImageProperty, value);
}
}
public Image Image2
{
get
{
return (Image)this.GetValue(CustomListDataItem.Image2Property);
}
set
{
this.SetValue(CustomListDataItem.Image2Property, value);
}
}
public string Name
{
get
{
return (string)this.GetValue(CustomListDataItem.NameProperty);
}
set
{
this.SetValue(CustomListDataItem.NameProperty, value);
}
}
#endregion Properties
#region Overrides
protected override void SetDataBoundItem(bool dataBinding, object value)
{
base.SetDataBoundItem(dataBinding, value);
if (value is INotifyPropertyChanged)
{
INotifyPropertyChanged item = value as INotifyPropertyChanged;
item.PropertyChanged += item_PropertyChanged;
}
}
#endregion Overrides
#region Private Methods
private void item_PropertyChanged(object sender, PropertyChangedEventArgs e)
{
if (e.PropertyName == "Image")
{
this.Image = (this.DataBoundItem as BussinessObject).Image;
}
if (e.PropertyName == "Image2")
{
this.Image2 = (this.DataBoundItem as BussinessObject).Image2;
}
if (e.PropertyName == "Name")
{
this.Name = (this.DataBoundItem as BussinessObject).Name;
}
}
#endregion Private Methods
}
public class CustomListVisualItem : RadListVisualItem
{
#region Fields
private RadLabelElement label = new RadLabelElement();
private ImagePrimitive image = new ImagePrimitive();
private ImagePrimitive image2 = new ImagePrimitive();
#endregion Fields
#region Initialization
static CustomListVisualItem()
{
RadListVisualItem.SynchronizationProperties.Add(CustomListDataItem.ImageProperty);
RadListVisualItem.SynchronizationProperties.Add(CustomListDataItem.Image2Property);
RadListVisualItem.SynchronizationProperties.Add(CustomListDataItem.NameProperty);
}
#endregion Initialization
#region Overrides
protected override Type ThemeEffectiveType
{
get
{
return typeof(RadListVisualItem);
}
}
protected override void CreateChildElements()
{
base.CreateChildElements();
this.label.StretchHorizontally = true;
var stack = new StackLayoutPanel { Orientation = Orientation.Horizontal };
image.ImageScaling = ImageScaling.SizeToFit;
image2.ImageScaling = ImageScaling.SizeToFit;
stack.Children.Add(label);
stack.Children.Add(image);
stack.Children.Add(image2);
this.Children.Add(stack);
}
protected override void PropertySynchronized(RadProperty property)
{
var dataItem = (CustomListDataItem)this.Data;
this.image2.Image = dataItem.Image2;
this.image.Image = dataItem.Image;
this.label.Text = dataItem.Name;
}
#endregion Overrides
}
}
Hope this helps, if you have any other questions or comments, please let me know,