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C# 抽象类小谈

最近在做一个测试系统,就是读取功率计上的数据,在上位机软件上显示出来。

电脑界面不是我们这次的主讲就略过,我们这里主要讲一个类的实现。

最开始领导给了一个 远方的三相功率计 给我让我写上位机,很简单,我一会就实现出来了。

由于是三相功率计,所以我们先写个一相的基类出来

public class OnePhase    {        public float V { get; set; }        public float A { get; set; }        public float W { get; set; }        public float VA { get; set; }        public float PF { get; set; }    }

 

远方的类

 public class PF9830    {        public PF9830()        {            P1 = new OnePhase();            P2 = new OnePhase();            P3 = new OnePhase();            P4 = new OnePhase();        }        public OnePhase P1 { get; set; }        public OnePhase P2 { get; set; }        public OnePhase P3 { get; set; }        public OnePhase P4 { get; set; }        public void GetValues(byte[] data)        {            /*             * 串口读取值的解释             *              * P1.V = ……             */        }    }

实现类

class Test    {        public Test()        {            PowerMeter = new PF9830();            Port = new SerialPort();            Port.DataReceived += new SerialDataReceivedEventHandler(Port_DataReceived);        }                public PF9830 PowerMeter { get; set; }        public SerialPort Port { get; set; }        void Port_DataReceived(object sender, SerialDataReceivedEventArgs e)        {            int length = Port.BytesToRead;            byte[] data = http://www.mamicode.com/new byte[length];            Port.Read(data, 0, length);            PowerMeter.GetValues(data);        }    }

工作很快就完成了,也正常运行。可是有一天,领导说远方的测试精度太差了,要换一个横河的功率计进行测试,最好有一个下拉列表,可以选择是哪个仪器。
我刚开始的时候直接再写一个横河的类出来,如下:

public class WT230    {        public WT230()        {            P1 = new OnePhase();            P2 = new OnePhase();            P3 = new OnePhase();            P4 = new OnePhase();        }        public OnePhase P1 { get; set; }        public OnePhase P2 { get; set; }        public OnePhase P3 { get; set; }        public OnePhase P4 { get; set; }        public void GetValues(byte[] data)        {            /*             * 串口读取值的解释             *              * P1.V = ……             */        }    }
class Test    {        public enum Powermeters { 远方, 横河 };        public Test()        {            PowerMeter1 = new PF9830();            PowerMeter2 = new WT230();            Port = new SerialPort();            Port.DataReceived += new SerialDataReceivedEventHandler(Port_DataReceived);        }                public PF9830 PowerMeter1 { get; set; }        public WT230 PowerMeter2 { get; set; }        public SerialPort Port { get; set; }        private Powermeters flag;        void Port_DataReceived(object sender, SerialDataReceivedEventArgs e)        {            int length = Port.BytesToRead;            byte[] data = http://www.mamicode.com/new byte[length];            Port.Read(data, 0, length);            switch (flag)            {                case Powermeters.横河:                    PowerMeter2.GetValues(data);                    break;                case Powermeters.远方:                    PowerMeter1.GetValues(data);                    break;                default:                    break;            }                 }    }

这里我们会发现WT230与PF9830两个类中有很多相同的代码,只是GetValues()这个方法不现。
再的就是实现类的有两个实例PowerMeter1与PowerMeter2,这与UI交互方面会存在很大的问题。

这里我们如果运用抽象类就可以很容易的解决上面的两个问题

首先我们先抽象出一个 功率计 的类出来:

 public abstract class PowerMeterBase    {        public PowerMeterBase()        {            P1 = new OnePhase();            P2 = new OnePhase();            P3 = new OnePhase();            P4 = new OnePhase();        }        public OnePhase P1 { get; set; }        public OnePhase P2 { get; set; }        public OnePhase P3 { get; set; }        public OnePhase P4 { get; set; }        public abstract void GetValues(byte[] data);//抽象方法    }

然后实例远方与横河的类

 public class PF9830:PowerMeterBase    {          public override void GetValues(byte[] data)        {            /*             * 串口读取值的解释             *              * P1.V = ……             */        }    }
public class WT230:PowerMeterBase    {          public override void GetValues(byte[] data)        {            /*             * 串口读取值的解释             *              * P1.V = ……             */        }    }

现在我们实现的UI交互类就简单多了

class Test    {        public enum Powermeters { 远方, 横河 };        public Test()        {                 Port = new SerialPort();            Port.DataReceived += new SerialDataReceivedEventHandler(Port_DataReceived);        }        public PowerMeterBase PowerMeter { get; set; } //实现多态        public SerialPort Port { get; set; }        private Powermeters flag;        void Port_DataReceived(object sender, SerialDataReceivedEventArgs e)        {            int length = Port.BytesToRead;            byte[] data = http://www.mamicode.com/new byte[length];            Port.Read(data, 0, length);            switch (flag)            {                case Powermeters.横河:                    PowerMeter = new WT230();                    PowerMeter.GetValues(data);                    break;                case Powermeters.远方:                    PowerMeter = new PF9830();                    PowerMeter.GetValues(data);                    break;                default:                    break;            }                 }    }

 

总结:

  功率计(抽象类)WT230(实类)PF9830(实类)

  对不同功率计的显示(多态)

 

C# 抽象类小谈