//引入命名空间
using System;
using System.Reflection;
using System.Reflection.Emit;
using System.Threading;

class LocalBuilder_Sample
{
    public static void Main()
    {
        // Create an assembly.
        AssemblyName myAssemblyName = new AssemblyName();
        myAssemblyName.Name = "SampleAssembly";

        AssemblyBuilder myAssembly = 
           Thread.GetDomain().DefineDynamicAssembly(myAssemblyName, 
               AssemblyBuilderAccess.RunAndSave);

        // Create a module. For a single-file assembly the module
        // name is usually the same as the assembly name.
        ModuleBuilder myModule = 
            myAssembly.DefineDynamicModule(myAssemblyName.Name, 
                myAssemblyName.Name + ".dll", true);

        // Define a public class 'Example'.
        TypeBuilder myTypeBuilder = 
            myModule.DefineType("Example", TypeAttributes.Public);

        // Create the 'Function1' public method, which takes an integer
        // and returns a string.
        MethodBuilder myMethod = myTypeBuilder.DefineMethod("Function1",
           MethodAttributes.Public | MethodAttributes.Static, 
           typeof(String), new Type[] { typeof(int) });

        // Generate IL for 'Function1'. The function body demonstrates
        // assigning an argument to a local variable, assigning a 
        // constant string to a local variable, and putting the contents
        // of local variables on the stack.
        ILGenerator myMethodIL = myMethod.GetILGenerator();

        // Create local variables named myString and myInt.
        LocalBuilder myLB1 = myMethodIL.DeclareLocal(typeof(string));
        myLB1.SetLocalSymInfo("myString");
        Console.WriteLine("local 'myString' type is: {0}", myLB1.LocalType);

        LocalBuilder myLB2 = myMethodIL.DeclareLocal(typeof(int));
        myLB2.SetLocalSymInfo("myInt", 1, 2);
        Console.WriteLine("local 'myInt' type is: {0}", myLB2.LocalType);

        // Store the function argument in myInt.
        myMethodIL.Emit(OpCodes.Ldarg_0 );
        myMethodIL.Emit(OpCodes.Stloc_1 );

        // Store a literal value in myString, and return the value.
        myMethodIL.Emit(OpCodes.Ldstr, "string value"  );
        myMethodIL.Emit(OpCodes.Stloc_0 );
        myMethodIL.Emit(OpCodes.Ldloc_0 );
        myMethodIL.Emit(OpCodes.Ret );

        // Create "Example" class.
        Type myType1 = myTypeBuilder.CreateType();
        Console.WriteLine("'Example' is created.");

        myAssembly.Save(myAssemblyName.Name + ".dll");
        Console.WriteLine( "'{0}' is created.", myAssemblyName.Name + ".dll" );

        // Invoke 'Function1' method of 'Example', passing the value 42.
        Object myObject2 = myType1.InvokeMember("Function1", 
            BindingFlags.InvokeMethod, null, null, new Object[] { 42 });

        Console.WriteLine("Example.Function1 returned: {0}", myObject2);
    }
}