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Binding to Classes Derived from CollectionBase

One of the data sources that you can bind the Chart control to is classes that you derived from the CollectionBase.

To bind Chart to a class derived from CollectionBase:

  1. First, you will need a class that you will be adding to the CollectionBase. For this example we will be using a class called Widget.

In Visual Basic:

Public Class Widget
    Public Sub New(ByVal name As String, ByVal marketValue As Double, _
      ByVal magnitude As Long)
        Me.Name = name
        Me.MarketValue = marketValue
        Me.Magnitude = magnitude
    End Sub
    Private _name As String
    Private _marketValue As Double
    Private _magnitude As Long
    Public Property Name() As String
        Get
            Return Me._name
        End Get
        Set(ByVal Value As String)
            Me._name = Value
        End Set
    End Property
    Public Property MarketValue() As Double
        Get
            Return Me._marketValue
        End Get
        Set(ByVal Value As Double)
            Me._marketValue = Value
        End Set
    End Property
    Public Property Magnitude() As Long
        Get
            Return Me._magnitude
        End Get
        Set(ByVal Value As Long)
            Me._magnitude = Value
        End Set
    End Property
End Class

In C#:

/// <summary>
/// Widget class.
/// </summary>
public class Widget
{
	/// <summary>
	/// Constructor
	/// </summary>
	/// <param name="name">Name</param>
	/// <param name="marketValue">Market value</param>
	/// <param name="magnitude">Magnitude</param>
	public Widget(string name, double marketValue, long magnitude)
	{
		this.Name=name;
		this.MarketValue=marketValue;
		this.Magnitude=magnitude;
	}
	private string name;
	private double marketValue;
	private long magnitude;
	/// <summary>
	/// Public property Name
	/// </summary>
	public string Name
	{
		get
		{
			return this.name;
		}
		set
		{
			this.name=value;
		}
	}
	/// <summary>
	/// Public property Market value
	/// </summary>
	public double MarketValue
	{
		get
		{
			return this.marketValue;
		}
		set
		{
			this.marketValue=value;
		}
	}
	/// <summary>
	/// Public property Magnitude
	/// </summary>
	public long Magnitude
	{
		get
		{
			return this.magnitude;
		}
		set
		{
			this.magnitude=value;
		}
	}
}

  1. Next you need to create a class that inherits from CollectionBase. For this sample we will be using the following class.

In Visual Basic:

Public Class MyCollection
  Inherits CollectionBase
	Public Sub Add(ByVal widget As Widget)
		Me.List.Add(widget)
	End Sub
	Default Public ReadOnly Property Item(ByVal index As Integer) As Widget
		Get
			Return CType(Me.List(index), Widget)
		End Get
	End Property
End Class

In C#:

/// <summary>
/// Custom collection
/// </summary>
public class MyCollection : CollectionBase
{
	/// <summary>
	/// Add a new item to the collection
	/// </summary>
	public virtual void Add(Widget widget)
	{
		this.List.Add(widget);
	}
	/// <summary>
	/// Gets or sets the element at the specified index.
	/// </summary>
	public Widget this[int index]
	{
		get
		{
			return this.List[index] as Widget;
		}
	}
}

  1. Once you have created the above mentioned classes you would then go about instantiating them in the following manner. Finally, bind the chart to the instance of MyCollection that is created.

In Visual Basic:

Private Sub Binding_to_Classes_Derived_from_CollectionBase_Load( _
  ByVal sender As System.Object, _
  ByVal e As System.EventArgs) Handles MyBase.Load
	Dim col As New MyCollection()
	col.Add(New Widget("Nondescript Widget", 6.3, 4))
	col.Add(New Widget("Oblique Widget", 4.2, 3))
	col.Add(New Widget("Diet Widget", 7.9, 2))
	col.Add(New Widget("Widget of mysterious origin", 9.5, 1))
	Me.UltraChart1.Data.DataSource = col
End Sub

In C#:

private void Binding_to_Classes_Derived_from_CollectionBase_Load(object sender,
  EventArgs e)
{
	MyCollection col = new MyCollection();
	col.Add(new Widget("Nondescript Widget", 6.3, 4));
	col.Add(new Widget("Oblique Widget", 4.2, 3));
	col.Add(new Widget("Diet Widget", 7.9, 2));
	col.Add(new Widget("Widget of mysterious origin", 9.5, 1));
	this.ultraChart1.Data.DataSource=col;
}