factory
factory 模式 从若干个可能类创建对象
public interface IHelloPrinter
{
void PrintHello();
}
public class EnglishHelloPrinter:IHelloPrinter
{
void PrintHello(){ System.Console.write("");
}
}
public class GermanHelloPrinter:IHelloPrinter
{
void PrintHello(){ System.Console.write("");
}
}
public class HelloFactory
{
public IHelloPrinter CreateHelloPrinter(string language)
{
switch(language)
{
case "de":
return new GermanHelloPrinter();
case "en":
return new EnglishHelloPrinter();
}
}
}