『SOLID 重構挑戰練習』3. 使用 物件導向設計的 多型 來重構程式碼

using System;
	using System.Collections.Generic;
	using System.Drawing;
	namespace RefactorSwitchPolymorphism
	{
	public class StringToColor
	{
	public Color Transfer(string name)
	{
	Color transferResult;
	switch (name.ToLower())
	{
	case "red":
	transferResult = Color.FromArgb(0xFF, 0xFF, 0x00, 0x00);
	break;
	case "green":
	transferResult = Color.FromArgb(0xFF, 0x80, 0x80, 0x80);
	break;
	case "blue":
	transferResult = Color.FromArgb(0xFF, 0x00, 0x00, 0xFF);
	break;
	default:
	throw new ArgumentException("不正確的顏色名稱");
	}
	return transferResult;
	}
	}
	namespace RefactorSwitchPolymorphism.Refactoring
	{
	#region 將不同顏色名稱轉換成為顏色物件的過程，設計成為不同的類別
	public abstract class ColorTransfer
	{
	public abstract Color Transfer();
	}
	public class TransferToRed : ColorTransfer
	{
	public override Color Transfer()
	{
	return Color.FromArgb(0xFF, 0xFF, 0x00, 0x00);
	}
	}
	public class TransferToGreen : ColorTransfer
	{
	public override Color Transfer()
	{
	return Color.FromArgb(0xFF, 0x80, 0x80, 0x80);
	}
	}
	public class TransferToBlue : ColorTransfer
	{
	public override Color Transfer()
	{
	return Color.FromArgb(0xFF, 0x00, 0x00, 0xFF);
	}
	}
	public class StringToColor
	{
	Dictionary<string, ColorTransfer> _colorMaps;
	public StringToColor()
	{
	_colorMaps = new Dictionary<string, ColorTransfer>()
	{
	{"Red", new TransferToRed() },
	{"Green", new TransferToGreen() },
	{"Blue", new TransferToBlue() },
	};
	}
	public Color Transfer(string name)
	{
	if (!_colorMaps.ContainsKey(name))
	throw new ArgumentException("不正確的顏色名稱");
	return _colorMaps[name].Transfer();
	}
	}
	#endregion
	}
	class Program
	{
	static void Main(string[] args)
	{
	string MyColorName = "Blue";
	Console.WriteLine("使用 Swith 來設計方法");
	StringToColor foo = new StringToColor();
	Color fooColor = foo.Transfer(MyColorName);
	Console.WriteLine($"{MyColorName} = A:{fooColor.A} R:{fooColor.R} G:{fooColor.G} B:{fooColor.B}");
	Console.WriteLine("Press any key for continuing...");
	Console.ReadKey();
	Console.WriteLine("使用 資料字典與多型 來重構方法，進行 Swith 需求設計");
	RefactorSwitchPolymorphism.Refactoring.StringToColor fooRefactoring = new RefactorSwitchPolymorphism.Refactoring.StringToColor();
	Color fooRefactoringColor = fooRefactoring.Transfer(MyColorName);
	Console.WriteLine($"{MyColorName} = A:{fooRefactoringColor.A} R:{fooRefactoringColor.R} G:{fooRefactoringColor.G} B:{fooRefactoringColor.B}");
	Console.WriteLine("Press any key for continuing...");
	Console.ReadKey();
	}
	}
	}