switch的模式中有一种叫类型模式，可以根据switch的类型来执行对应的case，这点在代码中用到的比较频繁，特别是在对应同类型对象的操作中。本例是把一组数据，转成一种格式，就是很简单的使用switch类型模式实现，具体见代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;namespace SwitchDemo;public class ClassOne
{public void Run(){var entity = new YamlFormatCreater();var data = new Data();Console.WriteLine(GetData(entity, data));}public string GetDataFormat(IFormatCreater entity, Data data) => entity switch{CSVFormatCreater csvFormatCreater => csvFormatCreater.ToCSV(data),JsonFormatCreater jsonFormatCreater => jsonFormatCreater.ToJson(data),XMLFormatCreater xmlFormatCreater => xmlFormatCreater.ToXML(data),YamlFormatCreater yamlFormatCreater => yamlFormatCreater.ToYAML(data),_ => "this format is not adapted"};
}public class Data
{public int ID { get; set; }public string? Name { get; set; }public string? Model { get; set; }
}
public interface IFormatCreater
{ }public class CSVFormatCreater : IFormatCreater
{public string ToCSV(Data data){return "To CSV";}
}
public class JsonFormatCreater : IFormatCreater
{public string ToJson(Data data){return "To JSON";}
}
public class XMLFormatCreater : IFormatCreater
{public string ToXML(Data data){return "To XML";}
}
public class YamlFormatCreater : IFormatCreater
{public string ToYAML(Data data){return "To YAML";}
}