爲WPF用戶控件datagrid創建屬性

我有一個名爲IGrid的數據網格的用戶控件。我想爲它添加GridViewColumnCollection屬性。爲WPF用戶控件datagrid創建屬性

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; 
     } 
    } 
}

從谷歌我有一段代碼`

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

在這裏，我可以在可視樹得到GridViewColumnCollection，我的問題是如何使用集合中添加一個新的類型（DataGridNumericColumn）以上代碼。