策略模式

定义

public interface ITraffic
{
    void Drive();
}

public class Car : ITraffic
{

    public void Drive()
    {
        Console.WriteLine("车在陆地行驶");
    }

}

public class Ship : ITraffic
{
    public void Drive()
    {
        Console.WriteLine("船在水上行驶");
    }
}

public class AirPlane : ITraffic
{

    public void Drive()
    {
        Console.WriteLine("飞机在天上飞");
    }
}

public class ErrorTraffic : ITraffic
{
    public void Drive()
    {
        Console.WriteLine("选择错误");
    }
}

public class TrafficConfig
{
    private ITraffic? _trafficType;

    public static readonly Dictionary<string, ITraffic> trafficsMap = new Dictionary<string, ITraffic>() {
        { "car",new Car()},
        { "ship",new Ship()},
        { "air",new AirPlane()}
    };
    //无法去掉
    public TrafficConfig(ITraffic traffic)
    {
        _trafficType = traffic;
    }
    //去掉IF ELSE
    public TrafficConfig(string trafficCode)
    {
        _trafficType = trafficsMap.GetValueOrDefault(trafficCode);
    }
    public void Drive()
    {
        _trafficType?.Drive();
    }
}

 

 

调用

 var code = "car";
 //if (code == "car")
 //{
 //    TrafficConfig traffic = new TrafficConfig(new Car());
 //}
 //else if (code == "ship")
 //{
 //    TrafficConfig traffic = new TrafficConfig(new Ship());
 //}
 //else if (code == "air")
 //{
 //    TrafficConfig traffic = new TrafficConfig(new AirPlane());
 //}
 //traffic.Drive();

 TrafficConfig traffic = new TrafficConfig(code);
 traffic.Drive();