Create a new method in runtime

Some one may need to use codes to create or edit a method in Axapta.
Here is an example to show how to create a lookup method for a form's field in runtime.
static void CreateFieldMethod(Args _args)
{
TreeNode tn1,tnAddr, methodsNode;
MemberFunction memberFunction;
str source;
;


//The reason why I use escape characters here is
//because this line of code is copied from standard Axapta application :)
tn1 = infolog.findNode(
"\\Forms\\Address\\Data Sources\\Address\\Fields\\AddrRecId");

tnAddr = infolog.findNode( "\\Forms\\Address" );
methodsNode = tn1.AOTfindChild( 'Methods' );
methodsNode.AOTadd('lookup');
memberFunction = methodsNode.AOTfindChild( 'lookup' );
source = @"public void lookup(FormControl _formControl, str _filterStr)
{
super(_formControl, _filterStr);
}" ;
memberFunction.AOTsetSource(source, false);
memberFunction.AOTsave();
methodsNode.AOTsave();
tnAddr.AOTcompile();
}