Haibo Luo's weblog

Type.GetType gives us the ability to get type back from a string. We pass a well-written type name string to it, and expect it return that type. Sometimes, to your surprise, it returns null. For example, Type.GetType("System.Data.SqlClient.SqlException...

Q : Assume we have 2000 unknown types; (however) we know each type has a constructor with integer as its' only parameter type. How to create objects 10000 times for each type (and make such late-new fast)? Activator.CreateInstance comes to my fingers...

Have you ever tried DynamicMethod, one of the coolest features in the .NET 2.0? Hope you have; otherwise, you can try it now with the examples 1 , 2 . Like emitting IL to MethodBuilder, we first get ILGenerator from a DynamicMethod, and make a series...

In order to interop with .NET libraries, we need first load in the assemblies we want to play with. The family of AddReference methods in the clr module serves the purpose. clr.AddReference clr.AddReferenceByName clr.AddReferenceByPartialName...

Reflection in .NET 2.0 ships with a new class MethodBody, which "provides access to information about the local variables and exception-handling clauses in a method body, and to the Microsoft intermediate language (MSIL) that makes up the method ...

Yes, reflection can get this done. Assume we have an Enum type - Colors, the following code will print the name and value for each member of it. foreach ( FieldInfo fi in typeof ( Colors ).GetFields( BindingFlags .Public | BindingFlags .Static...

You might have already read this : VS2005 made the last-minute DCR related to boxed Nullable<T>. Runtime now treats Nullable<T> differently from other generic value types when boxing: Int32 ? x = null ; object y = x; ...

The following steps are what I did to get Visual Studio ready as my IronPython (and IronRuby) editor. Install the latest internal dogfood build of Visual Studio 2008. you may use Visual Studio 2005 or download the VS 2008 public beta2 ; ...

I was glad to hear many positive feedbacks about the DebuggerVisualizer for DynamicMethod ; on the sad side, it shows our lack of good LCG debugging support (on which, Mike Stall is seeking your opinion ). Recently along with the ILReader update, I...

Compared to what I posted previously here (or what was used in the DynamicMethod visualizer ), this new version introduced the Visitor pattern . A do-nothing visitor ILInstructionVisitor is included; the users can focus on their domain-specific...

I do not know why anyone ever need this :) but few readers did ask me similar questions before. Solving this problem also demonstrates one more ILReader usage. To build a DynamicMethod, we can choose either DynamicILGenerator or DynamicILInfo . My...

As John mentioned in his post , every Reflection user should keep this in mind: our code should not count on the member order returned by GetFields, GetMethods and other similar GetXXXs calls. Given two fields (F1, F2) in one type, I think...

The GetCustomAttributes scenario ( ICustomAttributeProvider.GetCustomAttributes or Attribute.GetCustomAttributes , referred to as GetCA in this post) involves 3 pieces: a custom attribute type an entity which is decorated with the custom...

Python function may return multiple objects as a tuple. The .NET method can only return one object as the result of a call; in order to return more than one objects, by-ref parameters are needed. They are decorated with the parameter modifier (ref, out...

In C#, nested types can be defined in generic classes just like they would be in non-generic classes. For example: class G <T> { public class NestedC { } public enum NestedEnum { A, B } } Inside the nested type NestedC...

This was one ladybug in MSDN product feedback center. First of all, thanks to those who filed bugs or suggestions through it, which really help improve our product quality. No Name property in the LocalVariableInfo class is "by design...

I attached the ILVisualizer VS2008 solution in this post. There is no source code update; the only change is to upgrade the Microsoft.VisualStudio.DebuggerVisualizers.dll reference from version 8.0.0.0 to version 9.0.0.0. Just for your convenience...

clr is an IronPython built-in module, which provides some functionalities in order to interop with .NET. When writing "import clr" in a python module, it means you intend to leverage the .NET libraries. One classical example is python string's methods...

The following "Hello World" program shows how to use APIs in the class DynamicILInfo . MSDN documentation will have more details on this class in the next release. using System; using System.Reflection; using System.Reflection...

When you start interop'ing with .NET in IronPython, sooner or later, you will find that you are in need of creating an array as argument. There are mainly 2 ways to create array objects: Array with type indexing (for one-dimensional array object only...

When working on .NET projects, we often need to find the right API or the proper parameters to pass in to a particular method. Usually we search MSDN or turn to other search engines to solve such issue. Some people, however, prefer first-hand experience...

The type " System.Array " provides us a set of API for the late-bound array operations, including array creation ( Array.CreateInstance ), read/write access to array element ( Array.SetValue / Array.GetValue ). They are convenient to use. Let me start...

Type.FullName returns null when the type is not generic type definition but contains generic paramters. The rational behind this design is to ensure Type.FullName (if not null) can uniquely identify a type in an assembly; or given the string...

C# allows method overloading. Given an argument list, the compiler performs the overload resolution to select the best method to invoke. The chosen method token is baked into the assembly. IronPython does the method resolution at the IronPython run time...

IronPython offers a little bit more love to the Assembly object instance: we can directly access the assembly's top-level members (namespace, public type) via the dot operation. System.Reflection provides many ways to let you hold the assembly object...