ASP.NET & Csharp (C#)

ASP.NET & Csharp (C#) , Here you can find my posts about .NET c# .

Illustrates unloading an application domain

Posted on by coder 
   

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

/*
  Example18_4.cs illustrates unloading an application domain
*/

using System;
using System.Runtime.Remoting;
using System.Reflection;

public class Example18_4 
{

  public static void Main() 
  {

    // create a new appdomain
    AppDomain d = AppDomain.CreateDomain("NewDomain");
    
    // load an instance of the SimpleObject class
    ObjectHandle hobj = d.CreateInstance("Example18_2", "SimpleObject");
    // use a local variable to access the object
    SimpleObject so = (SimpleObject) hobj.Unwrap();
    Console.WriteLine(so.ToUpper("make this uppercase"));

    // unload the application domain
    AppDomain.Unload(d);
    Console.WriteLine(so.ToUpper("make this uppercase"));

  }

}


//===================================================

/*
  Example18_2.cs defines a simple object to create
*/

using System;

[Serializable]
public class SimpleObject 
{

  public String ToUpper(String inString)
  {
    return(inString.ToUpper());
  }

}

Illustrates runtime type invocation

Posted on by coder 
   

/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

/*
  Example17_6 illustrates runtime type invocation
*/

using System;
using System.Reflection;

public class Example17_6 
{

  public static void Main(string[] args) 
  {

    RandomSupplier rs;
    RandomMethod rm;

    // iterate over all command-line arguments
    foreach(string s in args)
    {
      Assembly a = Assembly.LoadFrom(s);

      // Look through all the types in the assembly
      foreach(Type t in a.GetTypes())
      {
        rs = (RandomSupplier) Attribute.GetCustomAttribute(
          t, typeof(RandomSupplier));
        if(rs != null)
        {
          // find the method in this class. assume that
          // the class only contains a single method.
          // can't use GetMethod() because we don't know
          // what the method is named
          foreach(MethodInfo m in t.GetMethods())
          {
            rm = (RandomMethod) Attribute.GetCustomAttribute(
             m, typeof(RandomMethod));
            if(rm != null)
            {
              // create an instance of the class
              Object o = Activator.CreateInstance(t);
              // create an empty arguments array
              Object[] aa = new Object[0];
              // invoke the method
              int i = (int) m.Invoke(o, aa);
              Console.WriteLine("Class {0} in {1} returned {2}",
                t, s, i);
            }

          }
        }
      }
    }

  }

}
///////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////
/*
Mastering Visual C# .NET
by Jason Price, Mike Gunderloy

Publisher: Sybex;
ISBN: 0782129110
*/

/*
  Example17_5a compiles into a library defining the RamdomSupplier attribute
  and the RandomMethod attribute
*/

using System;

// declare an attribute named RandomSupplier
[AttributeUsage(AttributeTargets.Class)]
public class RandomSupplier : Attribute
{
  public RandomSupplier()
  {
    // doesn't have to do anything
    // we just use this attribute to mark selected classes
  }
}

// declare an attribute named RandomMethod
[AttributeUsage(AttributeTargets.Method )]
public class RandomMethod : Attribute
{
  public RandomMethod()
  {
    // doesn't have to do anything
    // we just use this attribute to mark selected methods
  }
}
//===================================================
/*
  Example17_5b implements one class to supply random numbers
*/

// flag the class as a random supplier
[RandomSupplier]
public class OriginalRandom
{
  [RandomMethod]
  public int GetRandom()
  {
    return 5;
  }
}

//===================================================
/*
  Example17_5c implements one class to supply random numbers
*/

using System;

// flag the class as a random supplier
[RandomSupplier]
public class NewRandom
{
  [RandomMethod]
  public int ImprovedRandom()
  {
    Random r = new Random();
    return r.Next(1, 100);
  }
}

// this class has nothing to do with random numbers
public class AnotherClass
{
  public int NotRandom()
  {
    return 1;
  }
}
//===================================================
/*
  Example17_5d illustrates runtime type discovery
*/

using System;
using System.Reflection;

class Example17_5d 
{

  public static void Main(string[] args) 
  {

    RandomSupplier rs;
    RandomMethod rm;

    // iterate over all command-line arguments
    foreach(string s in args)
    {
      Assembly a = Assembly.LoadFrom(s);

      // Look through all the types in the assembly
      foreach(Type t in a.GetTypes())
      {
        rs = (RandomSupplier) Attribute.GetCustomAttribute(
         t, typeof(RandomSupplier));
        if(rs != null)
        {
          Console.WriteLine("Found RandomSupplier class {0} in {1}",
           t, s);
          foreach(MethodInfo m in t.GetMethods())
          {
            rm = (RandomMethod) Attribute.GetCustomAttribute(
             m, typeof(RandomMethod));
            if(rm != null)
            {
              Console.WriteLine("Found RandomMethod method {0}"
               , m.Name );
            }
          }        
        }
      }
    }

  }

}

Deeper Reflection: Invoking Functions

Posted on by coder 
   

/*
A Programmer's Introduction to C# (Second Edition)
by Eric Gunnerson

Publisher: Apress  L.P.
ISBN: 1-893115-62-3
*/

// 36 - Deeper into C#Deeper ReflectionInvoking Functions
// copyright 2000 Eric Gunnerson
// file=driver.cs
// compile with: csc driver.cs iprocess.cs
using System;
using System.Reflection;
using MamaSoft;

public class Deeper ReflectionInvokingFunctions
{
    public static void ProcessAssembly(string aname)
    {
        Console.WriteLine("Loading: {0}", aname);
        Assembly a = Assembly.LoadFrom (aname);
        
        // walk through each type in the assembly
        foreach (Type t in a.GetTypes())
        {
            // if it's a class, it might be one that we want.
            if (t.IsClass)
            {
                Console.WriteLine("  Found Class: {0}", t.FullName);
                
                // check to see if it implements IProcess
                if (t.GetInterface("IProcess") == null)
                continue;
                
                // it implements IProcess. Create an instance 
                // of the object.
                object o = Activator.CreateInstance(t);
                
                // create the parameter list, call it,
                // and print out the return value.
                Console.WriteLine("    Calling Process() on {0}", 
                t.FullName);
            object[] args = new object[] {55};
                object result;
                result = t.InvokeMember("Process",
                BindingFlags.Default |
                BindingFlags.InvokeMethod, 
                null, o, args);
                Console.WriteLine("    Result: {0}", result);
            }
        }
    }
    public static void Main(String[] args)
    {
        foreach (string arg in args)
        ProcessAssembly(arg);
    }
}


//=======================================================
// 36 - Deeper into C#Deeper ReflectionInvoking Functions
// copyright 2000 Eric Gunnerson
// file=IProcess.cs
namespace MamaSoft
{
    interface IProcess
    {
        string Process(int param);
    }
}

//=======================================================
// 36 - Deeper into C#Deeper ReflectionInvoking Functions
// copyright 2000 Eric Gunnerson
// file=process2.cs
// compile with: csc /target:library process2.cs iprocess.cs
using System;
namespace MamaSoft
{
    class Processor2: IProcess
    {
        Processor2() {}
        
        public string Process(int param)
        {
            Console.WriteLine("In Processor2.Process(): {0}", param);
            return("Shiver me timbers! ");
        }
    }
    class Unrelated
    {
    }
}

//========================================================
// 36 - Deeper into C#Deeper ReflectionInvoking Functions
// copyright 2000 Eric Gunnerson
// file=process1.cs
// compile with: csc /target:library process1.cs iprocess.cs
using System;
namespace MamaSoft
{
    class Processor1: IProcess
    {
        Processor1() {}
        
        public string Process(int param)
        {
            Console.WriteLine("In Processor1.Process(): {0}", param);
            return("Raise the mainsail! ");
        }
    }
}

Utilize MyClass without assuming any prior knowledge

Posted on by coder

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

// Utilize MyClass without assuming any prior knowledge.

using System;
using System.Reflection;

public class ReflectAssemblyDemo1 {
public static void Main() {
int val;
Assembly asm = Assembly.LoadFrom(“MyClasses.exe”);

Type[] alltypes = asm.GetTypes();

Type t = alltypes[0]; // use first class found

Console.WriteLine(“Using: ” + t.Name);

ConstructorInfo[] ci = t.GetConstructors();

// Use first constructor found.
ParameterInfo[] cpi = ci[0].GetParameters();
object reflectOb;

if(cpi.Length > 0) {
object[] consargs = new object[cpi.Length];

// initialize args
for(int n=0; n < cpi.Length; n++) consargs[n] = 10 + n * 20; // construct the object reflectOb = ci[0].Invoke(consargs); } else reflectOb = ci[0].Invoke(null); Console.WriteLine(" Invoking methods on reflectOb."); Console.WriteLine(); // Ignore inherited methods. MethodInfo[] mi = t.GetMethods(BindingFlags.DeclaredOnly | BindingFlags.Instance | BindingFlags.Public) ; // Invoke each method. foreach(MethodInfo m in mi) { Console.WriteLine("Calling {0} ", m.Name); // Get the parameters ParameterInfo[] pi = m.GetParameters(); // Execute methods. switch(pi.Length) { case 0: // no args if(m.ReturnType == typeof(int)) { val = (int) m.Invoke(reflectOb, null); Console.WriteLine("Result is " + val); } else if(m.ReturnType == typeof(void)) { m.Invoke(reflectOb, null); } break; case 1: // one arg if(pi[0].ParameterType == typeof(int)) { object[] args = new object[1]; args[0] = 14; if((bool) m.Invoke(reflectOb, args)) Console.WriteLine("14 is between x and y"); else Console.WriteLine("14 is not between x and y"); } break; case 2: // two args if((pi[0].ParameterType == typeof(int)) && (pi[1].ParameterType == typeof(int))) { object[] args = new object[2]; args[0] = 9; args[1] = 18; m.Invoke(reflectOb, args); } else if((pi[0].ParameterType == typeof(double)) && (pi[1].ParameterType == typeof(double))) { object[] args = new object[2]; args[0] = 1.12; args[1] = 23.4; m.Invoke(reflectOb, args); } break; } Console.WriteLine(); } } } //============================================================== /* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852 */ // A file that contains three classes. Call this file MyClasses.cs. using System; class MyClass { int x; int y; public MyClass(int i) { Console.WriteLine("Constructing MyClass(int). "); x = y = i; show(); } public MyClass(int i, int j) { Console.WriteLine("Constructing MyClass(int, int). "); x = i; y = j; show(); } public int sum() { return x+y; } public bool isBetween(int i) { if((x < i) && (i < y)) return true; else return false; } public void set(int a, int b) { Console.Write("Inside set(int, int). "); x = a; y = b; show(); } // Overload set. public void set(double a, double b) { Console.Write("Inside set(double, double). "); x = (int) a; y = (int) b; show(); } public void show() { Console.WriteLine("Values are x: {0}, y: {1}", x, y); } } class AnotherClass { string remark; public AnotherClass(string str) { remark = str; } public void show() { Console.WriteLine(remark); } } public class Demo12 { public static void Main() { Console.WriteLine("This is a placeholder."); } } [/csharp]

Locate an assembly, determine types, and create an object using reflection

Posted on by coder

/*
C#: The Complete Reference
by Herbert Schildt

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/

/* Locate an assembly, determine types, and create
an object using reflection. */

using System;
using System.Reflection;

public class ReflectAssemblyDemo {
public static void Main() {
int val;

// Load the MyClasses.exe assembly.
Assembly asm = Assembly.LoadFrom(“MyClasses.exe”);

// Discover what types MyClasses.exe contains.
Type[] alltypes = asm.GetTypes();
foreach(Type temp in alltypes)
Console.WriteLine(“Found: ” + temp.Name);

Console.WriteLine();

// Use the first type, which is MyClass in this case.
Type t = alltypes[0]; // use first class found
Console.WriteLine(“Using: ” + t.Name);

// Obtain constructor info.
ConstructorInfo[] ci = t.GetConstructors();

Console.WriteLine(“Available constructors: “);
foreach(ConstructorInfo c in ci) {
// Display return type and name.
Console.Write(” ” + t.Name + “(“);

// Display parameters.
ParameterInfo[] pi = c.GetParameters();

for(int i=0; i < pi.Length; i++) { Console.Write(pi[i].ParameterType.Name + " " + pi[i].Name); if(i+1 < pi.Length) Console.Write(", "); } Console.WriteLine(")"); } Console.WriteLine(); // Find matching constructor. int x; for(x=0; x < ci.Length; x++) { ParameterInfo[] pi = ci[x].GetParameters(); if(pi.Length == 2) break; } if(x == ci.Length) { Console.WriteLine("No matching constructor found."); return; } else Console.WriteLine("Two-parameter constructor found. "); // Construct the object. object[] consargs = new object[2]; consargs[0] = 10; consargs[1] = 20; object reflectOb = ci[x].Invoke(consargs); Console.WriteLine(" Invoking methods on reflectOb."); Console.WriteLine(); MethodInfo[] mi = t.GetMethods(); // Invoke each method. foreach(MethodInfo m in mi) { // Get the parameters ParameterInfo[] pi = m.GetParameters(); if(m.Name.CompareTo("set")==0 && pi[0].ParameterType == typeof(int)) { // This is set(int, int). object[] args = new object[2]; args[0] = 9; args[1] = 18; m.Invoke(reflectOb, args); } else if(m.Name.CompareTo("set")==0 && pi[0].ParameterType == typeof(double)) { // This is set(double, double). object[] args = new object[2]; args[0] = 1.12; args[1] = 23.4; m.Invoke(reflectOb, args); } else if(m.Name.CompareTo("sum")==0) { val = (int) m.Invoke(reflectOb, null); Console.WriteLine("sum is " + val); } else if(m.Name.CompareTo("isBetween")==0) { object[] args = new object[1]; args[0] = 14; if((bool) m.Invoke(reflectOb, args)) Console.WriteLine("14 is between x and y"); } else if(m.Name.CompareTo("show")==0) { m.Invoke(reflectOb, null); } } } } //================================================================ /* C#: The Complete Reference by Herbert Schildt Publisher: Osborne/McGraw-Hill (March 8, 2002) ISBN: 0072134852 */ // A file that contains three classes. Call this file MyClasses.cs. using System; class MyClass { int x; int y; public MyClass(int i) { Console.WriteLine("Constructing MyClass(int). "); x = y = i; show(); } public MyClass(int i, int j) { Console.WriteLine("Constructing MyClass(int, int). "); x = i; y = j; show(); } public int sum() { return x+y; } public bool isBetween(int i) { if((x < i) && (i < y)) return true; else return false; } public void set(int a, int b) { Console.Write("Inside set(int, int). "); x = a; y = b; show(); } // Overload set. public void set(double a, double b) { Console.Write("Inside set(double, double). "); x = (int) a; y = (int) b; show(); } public void show() { Console.WriteLine("Values are x: {0}, y: {1}", x, y); } } class AnotherClass { string remark; public AnotherClass(string str) { remark = str; } public void show() { Console.WriteLine(remark); } } public class Demo12 { public static void Main() { Console.WriteLine("This is a placeholder."); } } [/csharp]

Demonstrate dynamically invoking an object

Posted on by coder 
   

/*
C# Programming Tips &amp; Techniques
by Charles Wright, Kris Jamsa

Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/

// Invoke.cs -- Demonstrate dynamically invoking an object
//
//              Compile this program with the following command line:
//                  C:>csc Invoke.cs
using System;
using System.Reflection;

namespace nsReflection
{
    public class Invoke
    {
        static public void Main ()
        {
            // Load the Circle assembly.
            Assembly asy = null;
            try
            {
                asy = Assembly.Load ("Circle");
            }
            catch (Exception e)
            {
                Console.WriteLine (e.Message);
                return;
            }
            
            // Parameter array for a POINT object.
            object [] parmsPoint = new object [2] {15, 30};
            
            // Parameter array for a clsCircle object.
            object [] parmsCircle = new object [3] {100, 15, 30};
            
            // Get the type of clsCircle and create an instance of it.
            Type circle = asy.GetType("nsCircle.clsCircle");
            object obj = Activator.CreateInstance (circle, parmsCircle);
            
            // Get the property info for the area and show the area
            PropertyInfo p = circle.GetProperty ("Area");
            Console.WriteLine ("The area of the circle is " + p.GetValue(obj, null));
            
            // Get the POINT type and create an instance of it
            Type point = asy.GetType("nsCircle.POINT");
            object pt = Activator.CreateInstance (point, parmsPoint);
            
            // Show the point using object&#039;s ToString() method
            Console.WriteLine ("The point is " + pt.ToString ());
        }
    }
}

Using reflection to get information about an assembly

Posted on by coder 
   

/*
C# Programming Tips &amp; Techniques
by Charles Wright, Kris Jamsa

Publisher: Osborne/McGraw-Hill (December 28, 2001)
ISBN: 0072193794
*/

// Asy.cs -- Demonstrates using reflection to get information
//           about an assembly.
//
//           Compile this program with the following command line:
//               C:>csc Asy.cs
using System;
using System.Reflection;

public class Asy
{
    static public void Main ()
    {
        Assembly asy = null;
        try
        {
            asy = Assembly.Load ("Circle");
        }
        catch (Exception e)
        {
            Console.WriteLine (e.Message);
            return;
        }
        Type [] types = asy.GetTypes();
        foreach (Type t in types)
            ShowTypeInfo (t);
    }
    static void ShowTypeInfo (Type t)
    {
            Console.WriteLine ("{0} is a member of the {1} namespace", t.Name, t.Namespace);
            Console.WriteLine ("
Methods in {0}:", t.Name);
            MethodInfo [] methods = t.GetMethods ();
            foreach (MethodInfo m in methods)
                Console.WriteLine ("	" + m.Name);
            Console.WriteLine ("
Properties in {0}:", t.Name);
            PropertyInfo [] props = t.GetProperties ();
            foreach (PropertyInfo p in props)
                Console.WriteLine ("	" + p.Name);
            Console.WriteLine ("
Fields in {0}:", t.Name);
            FieldInfo [] fields = t.GetFields ();
            foreach (FieldInfo f in fields)
                Console.WriteLine ("	" + f.Name);
    }
}