'宣言 Public Class C1PrintViewTool Inherits C1.WPF.RichTextBox.Ribbon.RichTextBoxToggleButtonTool(Of Nullable(Of TextViewMode)) Implements IUpdateableTool
public class C1PrintViewTool : C1.WPF.RichTextBox.Ribbon.RichTextBoxToggleButtonTool<Nullable<TextViewMode>>, IUpdateableTool