我想从不知道类型的非泛型类中调用泛型类的方法。
interface IShape
{
SomeType AProperty; // Edit 2, sorry this should be a property.
}
interface IShapeEditor
{
}
class ShapeEditorBase : IShapeEditor
{
}
class RectangleEditor<T> : ShapeEditorBase where T : IShape
{
void Offset(T shape, int x, int y)
{
}
}
// This class must not be a generic class.
class OffsetRectangleButton
{
void ButtonPressed(IShapeEditor editor)
{
IShape shape = ashape; // from somewhere
dynamic editorInstance = editor;
editorInstance.Offset(shape, 1, 1); // Will trigger an exception here!
}
}
但是它触发了一个异常，它说 C# 在 ShapeEditorBase 中找不到 Offset 方法。
为什么不是 RectangleEditor，而是 ShapeEditorBase？
我该如何解决这个问题？或者也许是重构建议？
如果可能不反思（我听说这不好）。
====================
编辑以获取更多信息：
- 所有代码片段都位于作为控件的框架中。
- 应用程序通过泛型提供类型
- OffsetRectangleButton 或其他矩形按钮了解有关方法的所有信息，因为它们位于组件/dll 中。
=====================
编辑 3
- 使代码尽可能与问题相似
- 我重写代码以使前面的答案易于理解，而不是编辑前面的代码
- 请参阅 OffsetRectangleAction
- 问题：接口 IRectangleEditor 是否正确？（而且我可以继续解决OffsetRectangleAction）
- 问题：或者有更好的解决方案？
// =========================================
// Shape Display Component (a Winform Panel)
// =========================================
// In reality, rectangle is very complex implementation.
interface IRectangle // For rectangle display
{
Rectangle Rectangle { get; set; }
}
interface ILine // ICircle etc for other displays
{
Line Line { get; set; }
}
// Edit/Offset actions interface. It is represented by a button.
interface IAction
{
void Run(IShapeDisplay display);
}
// Container of all display's actions.
interface IActionContainer
{
IList<IAction> Actions; // Every action is related to a control (button, edit box, etc).
}
// Please see "OffsetRectangleAction".
// This class is container of all RectangleDisplays actions (as buttons in UI).
// This is also important, because this class shows why OffsetRectangleAction must not be generic.
// If OffsetRectangleAction is generic, then this class must be generic because it has OffsetRectangleAction.
// If this class generic, then in user interface has more than one OffsetRectangleAction buttons are created.
// And each OffsetRectangleAction edit certain type of Rectangle generic.
class RectangleActionContainer : IActionContainer
{
// List of all actions/buttons
IList<IAction> Actions;
RectangleActionContainer()
{
// It must be able to edit various types of rectangle.
this.Actions.Add(new EditAction());
this.Actions.Add(new OffsetRectangleAction());
}
}
// This class must not be a generic class. Please see RectangleActionContainer class.
// This is the most important problem!!!!!!!!!!!!!!!!!!!!!!!!!
// How can I access RectangleDisplay.RetctangleEditor.Offset or Edit
class OffsetRectangleAction: IAction // Similar also EditRectangleAction, InflateRectangleAction
{
void Run(IShapeDisplay display)
{
IRectangle rectangle = this.GelectedRectangle(); // from somewhere
// How to make it runs properly without exception.
dynamic rectangleDisplayInstance = display;
dynamic editHandler = rectangleDisplayInstance.EditHandler;
editHandler.Offset(rectangle, 1, 1); // Will trigger an exception here!
}
}
// RectangleEditor interface to edit rectangles and as rectangles container.
interface IRectangleEditor<T> where T : IRectangle // Generic because there are many type rectangle for various purposes.
{
IList<T> Rectangles { get; } // List of rectangle to be edited/visualized.
Edit(T rect, Rectangle dimension);
Offset(T rect, double x, double y);
}
// Shape display interface
interface IShapeDisplay
{
IActionContainer ActionContainer { get; }
void Draw(Graphics canvas);
}
// Base of all displays (rectangle, line, circle)
class ShapeDisplayBase : IShapeDisplay
{
IActionContainer ActionContainer { get; private set; }
virtual void Draw(Graphics canvas)
{
}
}
// Rectangle Display.
// Controller for displaying and bussines logic of rectangle shapes.
// ShapeDisplayBase inherited also for Line, Circular etc displays.
class RectangleDisplay<T> : ShapeDisplayBase where T : IShape
{
IRectangleEditor<T> RectangleEditor { get; private set; }
RectangleDisplay<T>(IRectangleEditor<T> editor)
{
this.RectangleEditor = editor;
}
override void Draw(Graphics canvas)
{
}
}
// Controller for the whole shape displays (Rectangle, Line, Circle etc.)
class ShapeDisplaysController
{
IList<IActionContainer> ActionContainers { get; private set; } // Action container for all displays (rectangle, line, etc)
IList<IShapeDisplay> ShapeDisplays { get; private set; } // Can be RectangleDisplay, LineDisplay, CircularDisplay
void RegisterDisplay(IShapeDisplay display)
{
this.ShapeDisplays = display;
// A type of displays can only one action container (eg: many rectangle types can be edited only with one edit button)
if (!ActionContainer.Contains(display))
{
ActionContainers.Add(display.ActionContainer);
}
}
// Show all shape display objects.
void Draw(Graphics canvas)
{
foreach(var display in this.ShapeDisplays)
{
display.Draw(canvas);
}
}
}
// ==========================
// Application
// ==========================
class RoundedRectangleEditHandler<T> : IRectangleEditor<T> where T : IRectangle
{
IList<T> Rectangles { get; private set;} // List of rectangle to be edited/visualized.
implementation...
}
class FillRectangleEditHandler<T> : IRectangleEditor<T> where T : IRectangle
{
IList<T> Rectangles { get; private set;} // List of rectangle to be edited/visualized.
implementation...
}
// There are many application that use ShapeViewer component.
// And every application has their own rectangle type, so we decided to use generic.
class ShapeViewerApp: Form
{
// Visualization control for shape.
private ShapeDisplaysController myShapeDisplaysController;
// Show shape list in grid.
private GridController myGridController;
static void Main()
{
this.myShapeDisplaysController = new ShapeDisplaysController();
var roundedRectangleEditHandler = new RoundedRectangleEditHandler<RoundedRect>();
var roundedRectangleDisplay = new RoundedRectangleDisplay<RoundedRect>(roundedRectangleEditHandler);
var fillRectangleEditHandler = new FillRectangleEditHandler<FillRectangle>();
var fillRectangleDisplay = new FillRectangleDisplay<FillRectangle>(fillRectangleEditHandler);
this.myShapeDisplaysController.Register(fillRectangleDisplay);
this.myShapeDisplaysController.Register(roundedRectangleDisplay);
this.myShapeDisplaysController.Register(lineDisplay);
this.myShapeDisplaysController.Register(circleDisplay);
// ShapeDisplaysController is a Winform Panel UI.
this.Controls.Add(this.myShapeDisplaysController.Control);
this.ShowDialog();
}
}