Create an object using reflection
/*
C#: The Complete Reference
by Herbert Schildt
Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/
// Create an object using reflection.
using System;
using System.Reflection;
class MyClass {
int x;
int y;
public MyClass(int i) {
Console.WriteLine("Constructing MyClass(int, int). ");
x = y = i;
}
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);
}
}
public class InvokeConsDemo {
public static void Main() {
Type t = typeof(MyClass);
int val;
// Get 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.\n");
// Construct the object.
object[] consargs = new object[2];
consargs[0] = 10;
consargs[1] = 20;
object reflectOb = ci[x].Invoke(consargs);
Console.WriteLine("\nInvoking 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);
}
}
}
}
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