在.NET中利用Remoting的數據進行序列化方法

　　一、 使用序列化類

　　序列化一個類，并通過網絡傳輸需要三步：

　　1、將要序列化的類創建成一個library對象。

　　2、編寫一個發送程序來創建要序列化類的實例，并發送。

　　3、編寫一個接收程序從流中讀取數據，并重新創建原來的序列化類。

　　① 編寫要序列化的類

　　每個要通過網絡傳輸數據的類必須在原代碼文件里使用[Serializable]標簽。這表明，類中所有的數據在傳輸時都將要被序列化。下面展示了如何創建一個可以序列化的類。

　　using System;

[Serializable] public class SerialEmployee { public int EmployeeID public string LastName;

public string FirstName;

public int YearsService;

public double Salary;

public SerialEmployee() { EmployeeID = 0;

LastName = null; FirstName = null;

YearsService = 0; Salary = 0.0; } }

　　為了使用該類來傳輸數據，必須現創建一個library文件： csc /t:library SerialEmployee.cs

　　② 編寫一個傳輸程序

　　創建數據類以后，可以創建一個程序來傳輸數據。可以使用BinaryFormatter和SoapFormatter類來序列化數據。

　　BinaryFormatter將數據序列化為二進制流。通常在實際數據中，增加一些信息，例如類名和版本號信息。

　　也可以使用SoapFormatter類使用XML格式來傳輸數據。使用XML的好處就是可以在任何系統和程序間傳遞數據。

　　第一必須創建一個流的實例來傳遞數據。可以是任何類型的流，包括FileStream，MemoryStream，NetworkStream。然后，可以創建一個序列化類，使用Serialize()方法來通過流對象傳遞數據：

　　Stream str = new FileStream( "testfile.bin", FileMode.Create, FileAccess.ReadWrite); IFormatter formatter = new BinaryFormatter(); formatter.Serialize(str, data); Iformatter類創建了一個用來序列化的類的實例(BinaryFormatter或者SoapFormatter)，使用Serialize()類來將數據序列化

　　using System;

using System.IO;

using System.Runtime.Serialization; using System.Runtime.Serialization.Formatters.Soap; class SoapTest { public static void Main() { SerialEmployee emp1 = new SerialEmployee();

SerialEmployee emp2 = new SerialEmployee();

emp1.EmployeeID = 1;

emp1.LastName = "Blum";

emp1.FirstName = "Katie Jane";

emp1.YearsService = 12;

emp1.Salary = 35000.50;

emp2.EmployeeID = 2;

emp2.LastName = "Blum";

emp2.FirstName = "Jessica";

emp2.YearsService = 9;

emp2.Salary = 23700.30;

Stream str = new FileStream("soaptest.xml", FileMode.Create, FileAccess.ReadWrite); IFormatter formatter = new SoapFormatter();

formatter.Serialize(str, emp1);

formatter.Serialize(str, emp2); str.Close(); } }

　　SoapFormatter類包含在System.Runtime.Serialization.Formatters.Soap命名空間，BinaryFormatter類包含在System.Runtime.Serialization.Formatters.Binary命名空間，Iformatter接口包含在System.Runtime.Serialization命名空間。

　　編譯代碼：CSC /r:SerialEmployee.dll SoapTest.cs

　　運行SoapTest.exe程序后，可以查看產生的soaptest.xml文件

　　 1 Blum Katie Jane 12 35000.5 2 Blum Jessica 9 23700.3

　　查看soaptest.xml文件，我們可以發現在序列化類中SOAP是如何定義每個數據元素。一個值得注意的重要XML數據特點如下：

　　"http://schemas.microsoft.com/clr/assem/SerialEmployee%2C%20Version%3D0.Â0.0.0.%2C%20Culture%3Dneutral%2C%20PublicKeyToken%3Dnull">

　　這里，XML中定義的數據使用了序列化數據類的實際類名。如果接收程序使用了另一個不同的類名，會和從流中讀取的XML數據不匹配。類不匹配，讀取將會失敗。

　　下面的代碼展示了如何序列化數據，將數據傳送到遠程系統。

　　using System;

using System.Net;

using System.Net.Sockets;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

class BinaryDataSender { public static void Main() { SerialEmployee emp1 = new SerialEmployee();

SerialEmployee emp2 = new SerialEmployee();

emp1.EmployeeID = 1;

emp1.LastName = "Blum";

emp1.FirstName = "Katie Jane";

emp1.YearsService = 12;

emp1.Salary = 35000.50;

emp2.EmployeeID = 2;

emp2.LastName = "Blum";

emp2.FirstName = "Jessica";

emp2.YearsService = 9;

emp2.Salary = 23700.30;

TcpClient client = new TcpClient("127.0.0.1", 9050);

IFormatter formatter = new BinaryFormatter();

NetworkStream strm = client.GetStream();

formatter.Serialize(strm, emp1);

formatter.Serialize(strm, emp2);

strm.Close();

client.Close(); } }

　　因為BinaryFormatter和SoapFormatter類需要一個Stream對象來傳遞序列化的數據，所以要使用一個TCP Socket對象或者一個TcpClient對象來傳遞數據，不能直接使用UDP。

　　③編寫一個接收程序

　　using System;

using System.Net;

using System.Net.Sockets;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters.Binary;

class BinaryDataRcvr { public static void Main() { TcpListener server = new TcpListener(9050);

server.Start();

TcpClient client = server.AcceptTcpClient();

NetworkStream strm = client.GetStream();

IFormatter formatter = new BinaryFormatter();

SerialEmployee emp1 = (SerialEmployee)formatter.Deserialize(strm); Console.WriteLine("emp1.EmployeeID = {0}", emp1.EmployeeID); Console.WriteLine("emp1.LastName = {0}", emp1.LastName); Console.WriteLine("emp1.FirstName = {0}", emp1.FirstName); Console.WriteLine("emp1.YearsService = {0}", emp1.YearsService); Console.WriteLine("emp1.Salary = {0}\n", emp1.Salary); SerialEmployee emp2 = (SerialEmployee)formatter.Deserialize(strm); Console.WriteLine("emp2.EmployeeID = {0}", emp2.EmployeeID); Console.WriteLine("emp2.LastName = {0}", emp2.LastName); Console.WriteLine("emp2.FirstName = {0}", emp2.FirstName); Console.WriteLine("emp2.YearsService = {0}", emp2.YearsService); Console.WriteLine("emp2.Salary = {0}", emp2.Salary); strm.Close(); server.Stop(); } } Winxp系統：c:\Windows　 c:\Windows\system32

　　二、 程序改進

　　在前面的程序中有一個假設：發送者的所有數據都被接收者接收。如果數據丟失，調用Deserialize()方法會發生錯誤。一個簡單的解決方法是將序列化數據放到MemoryStream對象中。MemoryStream對象將所有的序列化數據保存在內存中，可以很容易得到序列化數據的大小。當傳遞數據時，將數據大小和數據一起傳遞。

　　using System;

using System.IO;

using System.Net;

using System.Net.Sockets;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters.Soap;

class BetterDataSender { public void SendData (NetworkStream strm, SerialEmployee emp) { IFormatter formatter = new SoapFormatter(); MemoryStream memstrm = new MemoryStream();

formatter.Serialize(memstrm, emp);

byte[] data = memstrm.GetBuffer();

int memsize = (int)memstrm.Length;

byte[] size = BitConverter.GetBytes(memsize);

strm.Write(size, 0, 4); strm.Write(data, 0, memsize); strm.Flush();

memstrm.Close(); } public BetterDataSender() { SerialEmployee emp1 = new SerialEmployee();

SerialEmployee emp2 = new SerialEmployee();

emp1.EmployeeID = 1; emp1.LastName = "Blum";

emp1.FirstName = "Katie Jane";

emp1.YearsService = 12;

emp1.Salary = 35000.50;

emp2.EmployeeID = 2;

emp2.LastName = "Blum";

emp2.FirstName = "Jessica";

emp2.YearsService = 9;

emp2.Salary = 23700.30;

TcpClient client = new TcpClient("127.0.0.1", 9050);

NetworkStream strm = client.GetStream();

SendData(strm, emp1);

SendData(strm, emp2);

strm.Close(); client.Close(); } public static void Main() { BetterDataSender bds = new BetterDataSender(); } } 接收數據程序如下：

　　using System;

using System.IO;

using System.Net;

using System.Net.Sockets;

using System.Runtime.Serialization;

using System.Runtime.Serialization.Formatters.Soap;

class BetterDataRcvr { private SerialEmployee RecvData (NetworkStream strm) { MemoryStream memstrm = new MemoryStream();

byte[] data = new byte[4]; int recv = strm.Read(data, 0, 4);

int size = BitConverter.ToInt32(data, 0);

int offset = 0;

while(size > 0) { data = new byte[1024];

recv = strm.Read(data, 0, size);

memstrm.Write(data, offset, recv);

offset += recv; size -= recv; } IFormatter formatter = new SoapFormatter(); memstrm.Position = 0;

SerialEmployee emp = (SerialEmployee)formatter.Deserialize(memstrm);

memstrm.Close();

return emp; } public BetterDataRcvr() { TcpListener server = new TcpListener(9050);

server.Start();

TcpClient client = server.AcceptTcpClient();

NetworkStream strm = client.GetStream();

SerialEmployee emp1 = RecvData(strm);

Console.WriteLine("emp1.EmployeeID = {0}", emp1.EmployeeID); Console.WriteLine("emp1.LastName = {0}", emp1.LastName); Console.WriteLine("emp1.FirstName = {0}", emp1.FirstName); Console.WriteLine("emp1.YearsService = {0}", emp1.YearsService); Console.WriteLine("emp1.Salary = {0}\n", emp1.Salary); SerialEmployee emp2 = RecvData(strm); Console.WriteLine("emp2.EmployeeID = {0}", emp2.EmployeeID); Console.WriteLine("emp2.LastName = {0}", emp2.LastName); Console.WriteLine("emp2.FirstName = {0}", emp2.FirstName); Console.WriteLine("emp2.YearsService = {0}", emp2.YearsService); Console.WriteLine("emp2.Salary = {0}", emp2.Salary); strm.Close(); server.Stop(); } public static void Main() { BetterDataRcvr bdr = new BetterDataRcvr(); } }