method UnboundHandler.ReadItem (Index as Long, Source as Object, ItemHandle as Long)
The source requires an item.

TypeDescription
Index as Long A Long expression that specifies the index of the item to be requested
Source as Object The source object to be filled. 
ItemHandle as Long A Long expression that specifies the handle of the item in the source, that's associated with the requested index.
The ReadItem method is called every time the Source requires an item to be displayed.

The following VB sample, shows how ReadItem method should be implemented: 

Private Sub IUnboundHandler_ReadItem(ByVal Index As Long, ByVal Source As Object, ByVal ItemHandle As Long)
    With Source.Items
        .CellValue(ItemHandle, 0) = Index + 1
    End With
End Sub

The following VB/NET sample, shows how ReadItem method should be implemented: 

Public Sub ReadItem(ByVal Index As Integer, ByVal Source As Object, ByVal ItemHandle As Integer) Implements EXGRIDLib.IUnboundHandler.ReadItem
    With Source.Items
        .CellValue(ItemHandle, 0) = Index + 1
    End With
End Sub

The following C# sample, shows how ReadItem method should be implemented: 

public void ReadItem(int Index, object Source, int ItemHandle)
{
    (Source as EXGRIDLib.IGrid).Items.set_CellValue(ItemHandle, 0, Index + 1);
}

The following VFP sample , shows how ReadItem method should be implemented: 

function IUnboundHandler_ReadItem(Index, Source, ItemHandle)
    With Source.Items
        .CellValue(ItemHandle, 0) = Index + 1 
    EndWith
endfunc