Control Identification

Introduction

Up to 2002, Microsoft Windows programmers relied on a library called Win32 to create applications for the operating system. The Win32 library was the only resource of classes (in fact structures), functions, etc, that gave functional instructions to the operating system. The other languages such as Pascal, Visual Basic, etc, used directly or indirectly these resources in their own "dialect" to communicate with Microsoft Windows. The Win32 library is still around (it can never disappear unless the operating system changes completely) and serves as the platform for Microsoft Windows programming. To harmonize programming for this platform, Microsoft created the .NET Framework as a substitute library. This is the library used in Microsoft Visual Studio .NET programming environment. Most of the functionality of Win32 has been redefined in the .NET Framework. The operations were implemented in various libraries or assemblies. Some other operations, such as those related to the Registry, were kept in the Microsoft.Win32 namespace.

The Win32 library uses a concept called handle to represent each object of an application. A handle in Win32 is simply an unsigned integer used in place of a control. The new .NET Framework also uses handles to internally represent controls but defines a handle as a pointer to an integer. Based on this, every control has a handle. You have a choice of using it or not but it exists. The handle is created by the operating system when the application comes up. This means that you don't need to create it but you can access it to retrieve its value.

To access the handle to a control, you can call its Handle property. In the .NET Framework, the Handle property is defined as an IntPtr value. To retrieve the handle of a control, you can access its Handle property.