public void AnonHosted()
{
DynamicMethod hello = new DynamicMethod("Hello",
typeof(int),
new Type[] { typeof(string) });
ILGenerator helloIL = hello.GetILGenerator();
helloIL.Emit(OpCodes.Ldc_I4_2);
helloIL.Emit(OpCodes.Ret);
HelloInvoker hi =
(HelloInvoker)hello.CreateDelegate(typeof(HelloInvoker));
int ret = hi("Hello, World!");
Assert.AreEqual(2, ret);
object[] invokeArgs = { "Hello, World!" };
object objRet = hello.Invoke(null, invokeArgs);
Assert.AreEqual(2, objRet);
}
[Test] // bug #78253
public void DynamicMethodReference()
{
DynamicMethod hello = new DynamicMethod("Hello",
typeof(int),
new Type[] { typeof(string) },
typeof(DynamicMethodTest).Module);
Assert.IsNull(hello.DeclaringType, "#1");
DynamicMethod write = new DynamicMethod("Write",
typeof(int),
new Type[] { typeof(string) },
typeof(DynamicMethodTest));
Assert.IsNull(hello.DeclaringType, "#2");
MethodInfo invokeWrite = write.GetBaseDefinition();
ILGenerator helloIL = hello.GetILGenerator();
helloIL.Emit(OpCodes.Ldarg_0);
helloIL.EmitCall(OpCodes.Call, invokeWrite, null);
helloIL.Emit(OpCodes.Ret);
ILGenerator writeIL = write.GetILGenerator();
writeIL.Emit(OpCodes.Ldc_I4_2);
writeIL.Emit(OpCodes.Ret);
HelloInvoker hi =
(HelloInvoker)hello.CreateDelegate(typeof(HelloInvoker));
int ret = hi("Hello, World!");
Assert.AreEqual(2, ret, "#3");
object[] invokeArgs = { "Hello, World!" };
object objRet = hello.Invoke(null, invokeArgs);
Assert.AreEqual(2, objRet, "#4");
}
public static void Main()
{
// Create an array that specifies the types of the parameters
// of the dynamic method. This method has a string parameter
// and an int parameter.
Type[] helloArgs = { typeof(string), typeof(int) };
// Create a dynamic method with the name "Hello", a return type
// of int, and two parameters whose types are specified by the
// array helloArgs. Create the method in the module that
// defines the Test class.
DynamicMethod hello = new DynamicMethod("Hello",
typeof(int),
helloArgs,
typeof(Test).Module);
// <Snippet2>
// Create an array that specifies the parameter types of the
// overload of Console.WriteLine to be used in Hello.
Type[] writeStringArgs = { typeof(string) };
// Get the overload of Console.WriteLine that has one
// String parameter.
MethodInfo writeString =
typeof(Console).GetMethod("WriteLine", writeStringArgs);
// Get an ILGenerator and emit a body for the dynamic method.
ILGenerator il = hello.GetILGenerator();
// Load the first argument, which is a string, onto the stack.
il.Emit(OpCodes.Ldarg_0);
// Call the overload of Console.WriteLine that prints a string.
il.EmitCall(OpCodes.Call, writeString, null);
// The Hello method returns the value of the second argument;
// to do this, load the onto the stack and return.
il.Emit(OpCodes.Ldarg_1);
il.Emit(OpCodes.Ret);
// </Snippet2>
// <Snippet3>
// Create a delegate that represents the dynamic method. This
// action completes the method, and any further attempts to
// change the method will cause an exception.
HelloInvoker hi =
(HelloInvoker)hello.CreateDelegate(typeof(HelloInvoker));
// </Snippet3>
// Use the delegate to execute the dynamic method. Save and
// print the return value.
int retval = hi("\r\nHello, World!", 42);
Console.WriteLine("Executing delegate hi(\"Hello, World!\", 42) returned {0}",
retval);
// Do it again, with different arguments.
retval = hi("\r\nHi, Mom!", 5280);
Console.WriteLine("Executing delegate hi(\"Hi, Mom!\", 5280) returned {0}",
retval);
// <Snippet4>
// Create an array of arguments to use with the Invoke method.
object[] invokeArgs = { "\r\nHello, World!", 42 };
// Invoke the dynamic method using the arguments. This is much
// slower than using the delegate, because you must create an
// array to contain the arguments, and ValueType arguments
// must be boxed.
object objRet = hello.Invoke(null, invokeArgs);
Console.WriteLine("hello.Invoke returned {0}", objRet);
// </Snippet4>
}
