static void Main(string[] args)
{
var result = SomeClass.Calculate(1000);
Console.WriteLine(result);
var calc = new DynamicMethod("CalcMethod",
typeof(int),
new[] { typeof(int) },
typeof(Program).Module);
var il = calc.GetILGenerator();
// Define labels for loop and return from method
var loopStart = il.DefineLabel();
var methodEnd = il.DefineLabel();
// variable 0 : result = 0
il.DeclareLocal(typeof(int)); // declare local variable result
il.Emit(OpCodes.Ldc_I4_0); // Create local variable of Integer (4 bytes) with 0
il.Emit(OpCodes.Stloc_0); // Store the local variable
// variable 1 : i = 0
il.DeclareLocal(typeof(int)); // declare local variable result
il.Emit(OpCodes.Ldc_I4_0); // Create local variable of Integer (4 bytes) with 0
il.Emit(OpCodes.Stloc_1); // Store the local variable
// Mark beginning of loop
il.MarkLabel(loopStart);
il.Emit(OpCodes.Ldloc_1); // value of i now on evaluation stack
il.Emit(OpCodes.Ldc_I4, 10); // Create local variable of Integer (4 bytes) with value of 10
il.Emit(OpCodes.Bge, methodEnd); // If i >= 10, jump to method end
// i * x
il.Emit(OpCodes.Ldloc_1); // Load value of i to evaluation stack
il.Emit(OpCodes.Ldarg_0); // Load argument to evaluation stack
il.Emit(OpCodes.Mul); // multiply i * x
// result +=
il.Emit(OpCodes.Ldloc_0); // Load result onto evailation stack
il.Emit(OpCodes.Add); // Add result of multiplication (i) to local variable (result)
il.Emit(OpCodes.Stloc_0); // Store result in local variable
// increment i
il.Emit(OpCodes.Ldloc_1); //Load value of i to evaluation stack
il.Emit(OpCodes.Ldc_I4_1); // Load value of 1 to evaluation stack
il.Emit(OpCodes.Add); // Increment
il.Emit(OpCodes.Stloc_1); // ** Store the value i!!
// Return to loop start
il.Emit(OpCodes.Br, loopStart);
// When i > 10
il.MarkLabel(methodEnd);
il.Emit(OpCodes.Ldloc_0); // Load result to evaluation stack
il.Emit(OpCodes.Ret); // Return from method
// Create the delegate
var method = (Func <int, int>)calc.CreateDelegate(typeof(Func <int, // Parameter 1
int // Return type
>));
var result2 = method(1000);
Console.WriteLine(result);
}
