A .NET assembly is “signed” if the developer compiled the assembly with the private key of a digital signature. When the system later loads the assembly, it verifies the assembly with the corresponding public key. Occasionally you may need to determine whether an assembly you have loaded has been signed.
There is a very handy .NET class called ControlPaint in the System.Windows.Forms namespace that enables you to draw your own controls and control elements using the standard Windows style and theme. Buried in this rich class are four methods that enable you to lighten and darken colors:
It’s hard to believe the comprehensive .NET framework would omit such obvious functions as GetPixel and SetPixel from its Drawing library. Fortunately, we can access the GDI functions using Interop, as shown below. Notice the conversion required between the COLORREF integer used by the GDI methods and the Color structure used by our static .NET methods.
Sometimes you need a quick & easy way to search and replace text in a file. The following code shows how it can be done using the static methods on the Regex regular expression class. Because this sample loads the entire file contents in memory, is not appropriate for very large files.
You may wish to enable your WinForms application to run from a console window or command line. And when it does, you probably want to send output messages to the console window that launched your WinForms application.
Unfortunately Console.WriteLine()–the standard method of writing to the console window–by default will not work from a WinForms application. That’s because the console window that launched your WinForms application belongs to the cmd.exe process, which is separate from your WinForms application process.
When you attempt to add an assembly reference to a Visual Studio project, the Add Reference dialog appears with a list of registered global assemblies in the .NET tab:
Unfortunately, adding your assembly to the Global Assembly Cache (GAC) does NOT make it automatically appear in the Visual Studio list of installed assemblies; you must add your assembly manually as follows:
Sometimes you need to know which version of an assembly was loaded by your .NET application. The following code snippet makes it easy:
Playing the default Windows sounds from C# used to require InteropServices and system calls. Fortunately, .NET 2.0 includes a new System.Media namespace with three classes that simplify playing system sounds and audio files:
One of the things I miss about C++ is the #define keyword that allows you to create an abbreviated alias for a long type name. Fortunately, C# provides a way to alias a long namespace or class name while retaining full type-checking.
To alias a namespace or class name, use the using directive to define the alias as shown in the sample code below. Then you can use the alias anywhere you would normally use the class name or namespace. The scope of a using directive is limited to the file in which it appears.
If you use images in a .NET application, chances are you will find it more convenient to embed those images as resources in your project, rather than leaving them as separate files and trying to locate and load the images from disk when the application runs.
