/*
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! ");
}
}
}
Month: February 2011
Utilize MyClass without assuming any prior knowledge
/*
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
/*
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
/*
C# Programming Tips & 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's ToString() method
Console.WriteLine ("The point is " + pt.ToString ());
}
}
}
Using reflection to get information about an assembly
/*
C# Programming Tips & 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);
}
}
Use RandomNumberGenerator
using System;
using System.Security.Cryptography;
class MainClass {
public static void Main() {
byte[] number = new byte[32];
RandomNumberGenerator rng = RandomNumberGenerator.Create();
rng.GetBytes(number);
Console.WriteLine(BitConverter.ToString(number));
}
}
Random Color and Rectangle
using System;
using System.Drawing;
using System.Windows.Forms;
class RandomRectangle: Form
{
public static void Main()
{
Application.Run(new RandomRectangle());
}
public RandomRectangle()
{
Text = "Random Rectangle";
Timer timer = new Timer();
timer.Interval = 1;
timer.Tick += new EventHandler(TimerOnTick);
timer.Start();
}
void TimerOnTick(object obj, EventArgs ea)
{
Random rand = new Random();
int x1 = rand.Next(ClientSize.Width);
int x2 = rand.Next(ClientSize.Width);
int y1 = rand.Next(ClientSize.Height);
int y2 = rand.Next(ClientSize.Height);
Color color = Color.FromArgb(rand.Next(256),
rand.Next(256),
rand.Next(256));
Graphics grfx = CreateGraphics();
grfx.FillRectangle(new SolidBrush(color),
Math.Min(x1, x2), Math.Min(y1, y2),
Math.Abs(x2 - x1), Math.Abs(y2 - y1));
grfx.Dispose();
}
}

