What runs my C# application?

Question

When developing a C# project in Visual Studio, I have three options for output type. Console Application, Windows Application, and Class Library. AFAIK, the only difference between a DLL and an EXE, is the EXE should have an entry point defined, and that is called when the file is double clicked. However, when I launch an EXE built from a Console Application, a console window is created. So obviously something is happening other than the CLR getting launched and then calling my Main method. What launches the console window? When I launch an EXE built from a Windows Application, is some other code run also, or is it just my main method?

Answer 1

Your portable executable file(exe) will contain the information about what kind of application it is.

Subsystem flag of the IMAGE_OPTIONAL_HEADER defines what kind of user interface the application is built with.

IMAGE_SUBSYSTEM_WINDOWS_CUI defines the console application, IMAGE_SUBSYSTEM_WINDOWS_GUI defines the windows application and so on.

For more information Peering Inside the PE: A Tour of the Win32 Portable Executable File Format

Answer 2

The output type is a configuration parameter for your project which tells Visual Studio what to do when you compiled. If set to Console Application, it will generate an exe file with the code to launch the console window.

The different between a dll and an exe is more than the main method. Visual Studio generated additional codes in the exe file that creates the console and invoke the main method. For details of how the exe file performs this, refer to http://en.wikipedia.org/wiki/Portable_Executable .

Answer 3

In this link the inquisitor added some notes which mentioned the blog post (2nd link). Is it possible to build a Console app that does not display a console Window when double-clicked?

http://blogs.msdn.com/b/oldnewthing/archive/2009/01/01/9259142.aspx

The same content as Siram's answer https://stackoverflow.com/a/30084790/2005526 but to assist you with future searches these were the keywords used on google to locate the mentioned resources. "double click exe launches console"