为WPF用户控件datagrid创建属性

我有一个名为IGrid的数据网格的用户控件。我想为它添加GridViewColumnCollection属性。为WPF用户控件datagrid创建属性

public class DataGridNumericColumn : DataGridTextColumn 
{ 
    protected override object PrepareCellForEdit(System.Windows.FrameworkElement editingElement, System.Windows.RoutedEventArgs editingEventArgs) 
    { 
     TextBox edit = editingElement as TextBox; 
     edit.PreviewTextInput += OnPreviewTextInput; 
     return base.PrepareCellForEdit(editingElement, editingEventArgs); 
    } 
    void OnPreviewTextInput(object sender, System.Windows.Input.TextCompositionEventArgs e) 
    { 
     try 
     { 
      Convert.ToInt32(e.Text); 
     } 
     catch 
     { 
      e.Handled = true; 
     } 
    } 
}

从谷歌我有一段代码`

private Collection<DataGridColumn> field = new Collection<DataGridColumn>(); 
[Category("Data")] 
[Description("Column Creation")]      
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)] 
public Collection<DataGridColumn> Columns 
{ 
    get { return field; } 
}

在这里，我可以在可视树得到GridViewColumnCollection，我的问题是如何使用集合中添加一个新的类型（DataGridNumericColumn）以上代码。