chap25.lst

Csharp2完全参考手册源代码 详细的说明可以在书里看到 该书是08年刚出炉很新鲜

listing 1
// A simple Cipher component.  Call this file CipherLib.cs. 
 
using System.ComponentModel; 
 
namespace CipherLib { // put component in its own namespace 
 
  // Notice that CipherComp inherits Component. 
  public class CipherComp : Component {  
 
    // Encode a string. 
    public string Encode(string msg) { 
      string temp = ""; 
 
      for(int i=0; i < msg.Length; i++) 
        temp += (char) (msg[i] + 1); 
 
      return temp; 
    } 
 
    // Decode a string. 
    public string Decode(string msg) { 
      string temp = ""; 
 
      for(int i=0; i < msg.Length; i++) 
        temp += (char) (msg[i] - 1); 
 
 
      return temp; 
    } 
  } 
}

listing 2
// A client that uses CipherComp. 
 
using System; 
using CipherLib; // import CipherComp's namespace 
 
class CipherCompClient { 
  public static void Main() { 
    CipherComp cc = new CipherComp(); 
 
    string text = "This is a test"; 
 
    string ciphertext = cc.Encode(text); 
    Console.WriteLine(ciphertext); 
 
    string plaintext = cc.Decode(ciphertext); 
    Console.WriteLine(plaintext); 
 
    cc.Dispose(); // free resources 
  } 
}

listing 3
// A skeletal implementation of a component that uses Dispose(bool). 
class MyComp : Component { 
  bool isDisposed; // true if component is disposed 
 
  public MyComp { 
    isDispose = false; 
    // ... 
  } 
 
  ~MyComp() { 
    Dispose(false); 
  } 
 
  protected override void Dispose(bool dispAll) { 
    if(!isDisposed) { 
      if(dispAll) { 
        // release managed resources here 
        isDisposed = true; // set component to disposed 
      } 
      // release unmanaged resources here 
      base.Dispose(dispAll); 
    } 
  } 
}

listing 4
// An enhanced cipher component that maintains a log file.  
  
using System;  
using System.ComponentModel;  
using System.IO;  
  
namespace CipherLib {  
  
  // An Cipher component that maintains a log file. 
  public class CipherComp : Component {   
    static int useID = 0; 
    int id; // instance id 
    bool isDisposed; // true if component is disposed.  
    FileStream log; 
  
    // Constructor  
    public CipherComp() {  
      isDisposed = false; // component not disposed  
      try {  
        log = new FileStream("CipherLog" + useID, FileMode.Create);  
        id = useID; 
        useID++; 
      } catch (FileNotFoundException exc) {  
        Console.WriteLine(exc);  
        log = null; 
      }  
    }  
 
    // Destructor  
    ~CipherComp() {  
       Console.WriteLine("Destructor for component " 
                         + id); 
       Dispose(false);  
    }  
  
    // Encode the file. Return and store result. 
    public string Encode(string msg) {  
  
      string temp = "";  
  
      for(int i=0;i < msg.Length; i++)   
        temp += (char) (msg[i] + 1);          
  
      // Store in log file.  
      for(int i=0; i < temp.Length; i++)  
        log.WriteByte((byte) temp[i]);  
  
      return temp; 
    }  
  
    // Decode the message. Return and store result.  
    public string Decode(string msg) {  
  
      string temp = "";  
  
      for(int i=0; i < msg.Length; i++)  
        temp += (char) (msg[i] - 1);  
  
      // Store in log file.  
      for(int i=0; i < temp.Length; i++)  
        log.WriteByte((byte) temp[i]);  
 
      return temp; 
    }  
  
    protected override void Dispose(bool dispAll) {  
      Console.WriteLine("Dispose(" + dispAll + 
                        ") for component " + id); 
 
      if(!isDisposed) {  
        if(dispAll) {  
          Console.WriteLine("Closing file for " + 
                            "component " + id); 
          log.Close(); // close encoded file  
          isDisposed = true;  
        }  
        // no unmanaged resources to release  
        base.Dispose(dispAll);  
      }  
    }  
  }  
}

listing 5
// Another client that uses CipherComp.  
  
using System;  
using CipherLib; // import CipherComp's namespace  
  
class CipherCompClient {  
  public static void Main() {  
    CipherComp cc = new CipherComp();  
  
    string text = "Testing";  
  
    string ciphertext = cc.Encode(text);  
    Console.WriteLine(ciphertext);  
  
    string plaintext = cc.Decode(ciphertext);  
    Console.WriteLine(plaintext);  
 
    text = "Components are powerful."; 
 
    ciphertext = cc.Encode(text);  
    Console.WriteLine(ciphertext);  
  
    plaintext = cc.Decode(ciphertext);  
    Console.WriteLine(plaintext);  
  
    cc.Dispose(); // free resources  
  }  
}

listing 6
// Encode the file. Return and store result. 
public string Encode(string msg) {  
 
  // Prevent use of a disposed component. 
  if(isDisposed) { 
    Console.WriteLine("Error: Component disposed."); 
    return null; 
  } 
  
  string temp = "";  
  
  for(int i=0;i < msg.Length; i++)   
    temp += (char) (msg[i] + 1);          
  
  // Store in log file.  
  for(int i=0; i < temp.Length; i++)  
    log.WriteByte((byte) temp[i]);  
  
  return temp; 
}  
  
// Decode the message. Return and store result.  
public string Decode(string msg) {  
  
  // Prevent use of a disposed component. 
  if(isDisposed) { 
    Console.WriteLine("Error: Component disposed."); 
    return null; 
  } 
  
  string temp = "";  
  
  for(int i=0; i < msg.Length; i++)  
    temp += (char) (msg[i] - 1);  
  
  // Store in log file.  
  for(int i=0; i < temp.Length; i++)  
    log.WriteByte((byte) temp[i]);  
 
  return temp; 
}

listing 7
// Employ the using statement. 
  
using System;  
using CipherLib; // import CipherComp's namespace  
  
class CipherCompClient {  
  public static void Main() {  
 
    // cc will be disposed when this block ends. 
    using(CipherComp cc = new CipherComp()) { 
  
      string text = "The using statement.";  
  
      string ciphertext = cc.Encode(text);  
      Console.WriteLine(ciphertext);  
  
      string plaintext = cc.Decode(ciphertext);  
      Console.WriteLine(plaintext);  
    } 
 
  }  
}

listing 8
// Demonstrate a component container.  
  
using System;  
using System.ComponentModel;  
using CipherLib; // import CipherComp's namespace  
  
class UseContainer {  
  public static void Main(string[] args) {  
    string str = "Using containers."; 
    Container cont = new Container();  
     
    CipherComp cc = new CipherComp();  
    CipherComp cc2 = new CipherComp();  
  
    cont.Add(cc);  
    cont.Add(cc2, "Second Component");  
  
    Console.WriteLine("First message: " +  str);  
    str = cc.Encode(str);  
    Console.WriteLine("First message encoded: " +  
                      str);  
 
    str = cc.Decode(str);  
    Console.WriteLine("First message decoded: " +  
                      str);  
  
    str = "one, two, three";  
    Console.WriteLine("Second message: " +  str);  
  
    str = cc2.Encode(str);  
    Console.WriteLine("Second message encoded: " +  
                      str);  
  
    str = cc2.Decode(str);  
    Console.WriteLine("Second message decoded: " +  
                      str);  
  
    Console.WriteLine("\ncc2's name: " + cc2.Site.Name);  
  
    Console.WriteLine(); 
 
    // Release both components.  
    cont.Dispose();  
  }  
}