Debugging C# Components

You can inspect the source code of your C# components while your application is running. Debugging of C# code is supported for the following IDEs:

• Visual Studio Code (recommended)
• Microsoft Visual Studio (2019)

You can also make use of logging and console messages for debugging purposes.

Printing messages to the log file and console helps monitoring overall progress of execution of your application and report errors which can be used in debugging. Log class makes it possible to print formatted string messages to the log file and the console.

Console.Run("show_messages 1");

The code below demonstrates how to print various types of messages:

// auxiliary variables for messages
string file_name = "file.txt";
int ID = 10;
			
// reporting an error message
Log.Error("Loading mesh: can't open \"{0}\" file\n", file_name);

// reporting a message
Log.Message("-> Added {0} UI elements.\n", ID);
	
// reporting a warning message
Log.Warning("ID of the \"{0}\" file: {1}.\n", file_name, ID);
	
// reporting a fatal error message to the log file and closing the application
Log.Fatal("FATAL ERROR reading \"{0}\" file!\n", file_name);

See Also#

Visual Studio Code is known for its excellent debugging tools. Built-in debugging support is available for the Node.js runtime, while others are implemented as extensions.

First of all, make sure that C# extension for Visual Studio Code is installed. If not, open the command palette in VS Code (press F1) and run Extensions: Install Extensions. Enter C# in the search box and press Enter. Select the extension and click Install If you have previously installed the C# extension, make sure that you have a recent version. You can check this by opening the command palette (press F1) and running Extensions: Show Installed Extensions.

In VS Code, actually there are two debugging modes handling two different workflows:

• Launch - debugging your application in the IDE, right after buiding and launching it.
• Attach - connecting to an already running instance of your application to debug it.

To start debugging you should bring up the Run view first. To do this select the Run icon in the Activity Bar on the side of VS Code or use the keyboard shortcut Ctrl+Shift+D.

Debugging in IDE#

Debugging via Attaching to Running Application#

Setting Breakpoints#

For more detailed information on debugging in Visual Studio Code please follow this link.

Debugging in IDE#

Debugging via Attaching to Running Application#

Setting Breakpoints#

For more detailed information on debugging in Microsoft Visual Studio please follow this link.

There is an issue taking place when debugging your application on Linux. After reaching a breakpoint the mouse cursor is grabbed by the Engine making it impossible to switch back to code editor. This section describes a workaround helping you overcome this issue.

The workflow is as follows:

1. Insert the following code to AppSystemLogic.cs or to any component's code:
   Source code (C#)

   public class Debugger
   {
       public static void ReleaseMouse()
       {
           App.MouseGrab = false;
           App.MouseCursorHide = false;
           App.MouseCursorNeedUpdate = true;
           App.UpdateMouseCursor();
       }
   }

2. Then we can put a breakpoint anywhere in the code, launch the debug process as described above, and test our application
3. After reaching the breakpoint, switch focus to the Debug Console window by hitting Ctrl + Shift + Y on the keyboard
4. Type the following line in the console:
   Source code (C#)

   Debugger.ReleaseMouse();

   and press Enter
   
5. Mouse cursor is unlocked!

You have to type this only once, then you can perform these actions via hotkeys:
[Ctrl + Shift + Y] -> Arrow_Up -> [Enter] (Visual Studio Code).

The same approach works for other IDEs as well. Each of them has its own "Debug Console", enabling you to execute code when the application is paused. So, you should locate it, open, and execute this code: Debugger.ReleaseMouse();.