枚举\位域\结构综合实验

1.枚举项和数值,字符串如何互相转换?2.结构和byte[]数组间如何互相转换? 这在通讯上普遍使用!
3.位域在工控上DIO控制普遍使用,如何借鉴.
OK,上代码!

using System;
using System.Runtime.InteropServices;
//http://www.cnblogs.com/pato/archive/2011/08/15/2139705.html
//https://msdn.microsoft.com/zh-cn/library/asx0thw2%28v=vs.110%29.aspx

namespace EnumStructDemo
{
    /// <summary>
    /// 测量类型:仪迪检测设备测量的类型
    /// </summary>
    public enum MeasureType : byte
    {
        ITEM_NULL = 0,    //空
        ITEM_NY = 1,      //耐压
        ITEM_JD = 2,      //接地
        ITEM_JY = 3,      //绝缘
        ITEM_XL = 4,      //泄漏
        ITEM_GL = 5,      //功率
        ITEM_QD = 6,      //启动
        ITEM_KD = 7       //开短
    }

    /// <summary>
    /// Binary flag, flag enum. 
    /// 二进制位标志,一个枚举实例包含多个枚举值
    /// 输入控制信号：到达位置，测量结束
    /// </summary>
    [System.Flags()]
    public enum DigitalIN : byte
    {
        PositionOK = 0x01,
        idiMeasureFinish = 0x02,
    }
    /// <summary>
    /// 输出控制信号:仪迪设备开始测量,启动传动点击,点亮报警灯
    /// </summary>
    [System.Flags()]
    public enum DigitalOut : byte
    {
        idiStart = 0x01,    //first bit is true, others is false
        chuandong = 0x02,   //second bit is true,...
        light = 0x04,       //third bit is true,....
    }

 
    /// <summary>
    /// 仪迪命令数据帧结构定义
    /// </summary>
    public struct Frame
    {
        public byte Head;       //0.帧头 'I'
        public byte Protocal;   //1.协议编号 '1'
        public byte AddrHigh;   //2-3.通讯地址高位在前，占用2字节：0~16383
        public byte AddrLow;
        public byte bytCount;   //4.本帧总字节数
        public byte Reserve;    //5.保留，总是0
        public byte Command;    //6.主命令编号**
        public byte frameEnd;   //7.帧尾，总是'D'
        public byte chkSum;     //8.校验和，所有字节和的低字节
        public void Display() { }
    }

    /// <summary>
    /// struct to byte
    /// </summary>
    /// <param name="obj">truct object</param>
    /// <returns>string array</returns>
    public class StructConvert
    {
        /// <summary>
        /// 根据传入的结构对象,返回对应的字节数组的引用.
        /// </summary>
        /// <param name="obj">传入对象</param>
        /// <returns>托管字节数组</returns>
        public static byte[] StructToBytes(object obj)
        {
            int size = Marshal.SizeOf(obj);
            byte[] bytes = new byte[size];//在托管堆上分配字节数组
            //Allocates memory from the unmanaged memory of the process by using the pointer to the specified number of bytes.
            IntPtr structPtr = Marshal.AllocHGlobal(size);
            //Marshals data from a managed object to an unmanaged block of memory.
            //从托管对象obj封装数据到非托管内存块
            Marshal.StructureToPtr(obj, structPtr, false);
            //Copies data from an unmanaged memory pointer to a managed 8-bit unsigned integer array.
            Marshal.Copy(structPtr, bytes, 0, size);
            Marshal.FreeHGlobal(structPtr);
            return bytes;
        }

        /// <summary>
        /// (StructName)convert.BytesToStruct(bytes, StructName.GetType());
        /// </summary>
        /// <param name="bytes">byte array</param>
        /// <param name="structType">struct type</param>
        /// <returns>the converted struct </returns>
        public static object BytesToStruct(byte[] bytes, Type structType, int indexFrom = 0)
        {
            //结构的大小总是>=字节数组, 拷贝字节数组到结构,取字节数组大小合适
            int sizeStruct = Marshal.SizeOf(structType);
            int sizeBytes = bytes.Length;

            //通过使用指定的字节数，从进程的非托管内存中分配内存。分配目标对象缓冲区
            IntPtr structPtr = Marshal.AllocHGlobal(sizeStruct);
            //将数据从一维托管 8 位无符号整数数组复制到非托管内存指针。拷贝bytes到缓冲区
            Marshal.Copy(bytes, indexFrom, structPtr, sizeBytes);
            //将数据从非托管内存块封送到新分配的指定类型的托管对象,传回托管对象的引用. 非托管内存块可销毁!
            //Marshals data from an unmanaged block of memory to a [newly allocated managed object] of the specified type.
            object objStruct = Marshal.PtrToStructure(structPtr, structType);
            //释放以前从进程的非托管内存中分配的内存。
            //Frees memory previously allocated from the unmanaged memory of the process.
            Marshal.FreeHGlobal(structPtr);
            return objStruct;
        }


    }
    class Program
    {
        static void Main(string[] args)
        {
            //*************枚举测试***
            foreach (var item in Enum.GetNames(typeof(MeasureType)))
                Console.WriteLine(item);
            //根据数值获得枚举对象,接收仪器数据后,分析测试数据的类型
            MeasureType meas = (MeasureType)1;//1代表耐压
            meas = (MeasureType)Enum.Parse(typeof(MeasureType), "ITEM_NY", ignoreCase: true);
            //获取枚举对象的[数值],串口发送指令时可用枚举项代表命令类型
            byte jd = (byte)MeasureType.ITEM_JD;//接地是2
            //测试枚举项是否为指定标识,如是否为耐压测试
            bool ny = meas.HasFlag(MeasureType.ITEM_NY);
            Console.WriteLine("jd={0},ny={1}", jd, ny);//jd = 2,ny = True

            //*************位域测试***
            DigitalOut DI = DigitalOut.light | DigitalOut.chuandong;
            Console.WriteLine("{0}\tDI={1}", DI, (byte)DI);//chuandong, light DI = 6
            if ((DI & DigitalOut.idiStart) > 0)
                Console.WriteLine("启动仪迪测试...");

            //*************结构测试***
            Frame frame = new Frame();//结构初始化,值类型为0,引用类型为null
            
            UInt16 a = 5;
            byte b = 0xf1;
            int c = 0xf1f2;
            Int64 d = c;
            int size = Marshal.SizeOf(frame);
            size = Marshal.SizeOf(a);//2
            //size = Marshal.SizeOf(DI);//Error!
            size = Marshal.SizeOf(b);//1
            size = Marshal.SizeOf(c);//4
            size = Marshal.SizeOf(d);//8

            byte[] bytMeasStart = { 0x49, 0x31, 0x00, 0x01, 0x08, 0x00, 0x00, 0x44, 0xC7 };
            frame = (Frame)StructConvert.BytesToStruct(bytMeasStart, frame.GetType());
            byte[] bytNew = StructConvert.StructToBytes(frame);
            //frame.chkSum = 199, bytNew[8] = 199
            Console.WriteLine("frame.chkSum={0}, bytNew[8]={1}", frame.chkSum, bytNew[8]);

            Console.ReadKey();
        }
    }
}