Good Way to Debug Visual Studio Designer Errors - visual-studio

Is there a good way to debug errors in the Visual Studio Designer?
In our project we have tons of UserControls and many complex forms. For the complex ones, the Designer often throws various exceptions which doesn't help much, and I was wondering if there's some nice way to figure out what has gone wrong.
The language is C#, and we're using Visual Studio 2005.

I've been able to debug some control designer issues by running a second instance of VS, then from your first VS instance do a "Debug -> Attach to Process" and pick "devenv".
The first VS instance is where you'll set your breakpoints. Use the second instance to load up the designer to cause the "designer" code to run.

See Debugging Design-Time Controls (MSDN).

It has been a pain in 2005 and still is in 2015. Breakpoints will often not hit, probably because of the assemblies being shadow copied or something by the designer(?). The best you can do is to break manually by introducing a call to Debugger.Break(). You may wrap it into a compiler conditional as so:
#if DEBUG
System.Diagnostics.Debugger.Break();
#endif
int line_to = break; // <- if a simple breakpoint here does not suffice

I have had this happen many times and it is a real pain.
Firstly I'd suggest attempting to follow the stack trace provided by the designer, though I found that often simply lists a bunch of internals stuff that isn't much use.
If that doesn't work then try compiling and determining the exception from there. You really are flying blind which is the problem. You could then try simply running the code and seeing what exception is raised when you run it, that should give you some more information.
A last-gasp approach could be to remove all the non-generated code from the form and gradually re-introduce it to determine the error.
If you're using custom controls you could manually remove the generated code related to the custom controls as well if the previous method still results in an error. You could then re-introduce this step-by-step in the same way to determine which custom control is causing the problem, then go and debug that separately.
Basically as far as I can tell there's no real way around the problem other than to slog it out a bit!

I discovered why sometimes breakpoints are not hit. In the Attach to Process dialog, "Attach to:" type has to be "Select..."'d.
Once I changed to "Managed 4.0, 4.5", breakpoints for a WinRT application were hit. Source: Designer Debugging in WinRT.

Each one is different and they can sometimes be obscure. As a first step, I would do the following:
Use source control and save often. When a designer error occurs, get a list of all changes to the affected controls that have occurred recently and test each one until you find the culprit
Be sure to check out the initialization routines of the controls involved. Very often these errors will occur because of some error or bad dependency that is called through the default constructor for a control (an error that may only manifest itself in VS)

You can run a second instance of VS and attach it to the first instance of VS (Ctrl+Alt+P). In the first instance set the breakpoints, in the second instance run the designer, and the breakpoint will fire. You can step through the code, but Edit-and-Continue will not work.
For Edit-and-Continue to work, set you control library's debug options to run a VS with the command line argument being the solution filename. Then you can simply set the breakpoints and hit F5. It will debug just like user code! As a side note, you can do this will VS and Office add-ins also.

This worked for me for Visual Studio 2022:
I opened a second Visual Studio instance
In the second instance I clicked Debug -> Attach to Process...
I selected DesignToolsServer from the process list
More details: https://learn.microsoft.com/en-us/dotnet/desktop/winforms/controls/walkthrough-debugging-custom-windows-forms-controls-at-design-time?view=netframeworkdesktop-4.8

Related

Why is there no way to 'break on next statement' in Visual Studio?

I have been given a project that is the biggest pile of spaghetti I have ever seen, with 0 unit tests or any obvious naming conventions.
I find it hard to believe there is still no way while running in Debug to have Visual Studio automatically break on the next executing line of solution code.
In this case, I know the code is hitting a specific 5000 line of code file - but there isn't even an easy way to just write a breakpoint to every single line!
Is there any logical reason why in 2017 (or even 2010) this functionality doesn't exist?
Or perhaps it does and I haven't found out how!
Is there any logical reason why in 2017 (or even 2010) this functionality doesn't exist?
Please Put a break point in your code -> debug, then Right click on the text editor in VS, you will see below:
You can use the "Break all" button in the visual studio (Ctrl+Alt+Break is the default shortcut).
You might need to switch between the running threads in order to see highlighted instruction within your code.
Then you can just continue debugging, as usual.
If you do not see any of those two controls, go to View->Toolbars and check both "Debug" and "Debug Location".

Visual Micro automatically inserts a breakpoint when no breakpoints are present

I am using the Visual Micro extension for Microsoft Visual Studio, which allows me to debug my Arduino project (in opposed to the Sketch IDE).
For some strange reason, when no breakpoints are present, it automatically adds a breakpoint at the beginning of the loop function.
When running via the debugger, I can simply remove it and continue running.
However, I cannot do the same when running without a debugger (i.e., upon power-up), since breakpoints seem to be "embedded" into the code as additional code segments (though I'm not really sure how explain the fact that the debugger allows me to remove a breakpoint).
Here is an illustration of the problem:
Now, I've been able to work-around it by adding a piece of "dead code" with a breakpoint:
if (0)
{
// insert a breakpoint here
}
But this feels kinda "clumsy".
I suppose that if there is a solution to this problem, then it lies somewhere in here:
But I have not able to find it, so any help will be highly appreciated.
Found the answer!
It turns out that all I needed was to hover on top of the breakpoint and read the tooltip carefully:
As you can read on the bottom line of this tooltip, in order to switch off that automatically-generated breakpoint, we only need to disable the Visual Micro's Tutorial Mode:
And voilà - we're all done!

Debugging with unity

At the current moment, what I'm doing is that I'm opening Unity, double click on one of those scripts I've written, then MonoDevelop gets opened, now I have to close unity and in MonoDevelop I do Run >> Run with >> Unity Debugger.
After this Unity gets opened and when I press the play button in unity the debugging session starts. But once only. If I stop this session in either Unity or MonoDevelop I have to repeat this whole procedure all over again, which is very tedious. I have to open Unity, close Unity, (I have to close it because next step which is Run >> Run with >> Unity Debugger will open unity and if unity is already opened I'm getting error saying that only one instance of unity can open one project at a time).
What I'm asking is:
Is there any better workflow which would free me from this tedious switching on and off Unity, and every time I stop debugging session I would just start normally without doing these tedious repetitions?
Use 'Attach' in MonoDevelop's debug menu; you should be able to attach to the running Unity process that way. (You may need to ensure that the appropriate option is turned on in Unity's preferences).
Another way to debug is by using the:
Debug.LogError("foo");
or
Debug.LogWarning("foo");
Another note is that you can actually bind objects to the Log. This will cause the editor to highlight the object is question in the event you are iterating over a list of GameObjects. i.e.:
Debug.LogWarning("this object broke", gameObject);
If you turn on "Error Pause" in the console window, the game will automatically pause when the LogError is met. But be warned, it will pause whenever an error is thrown.
I've always changed the default script editor (unity preferences -> external tools -> external script editor) to visual studio. This lets you use breakpoints and preprocessor macros to make debugging much easier. When you want to start debugging press f5 in visual studio to connect it to unity then play like normal and if a breakpoint is hit visual studio takes over.
You don't have to change anything else and you won't have to keep opening and closing things like you are now.
UnityVS is now officially part of Microsoft and is available as an add-on for vs 2010,12 and 13. Here's the MSDN blogpost linking to the various versions: http://blogs.msdn.com/b/visualstudio/archive/2014/07/29/visual-studio-tools-for-unity-1-9.aspx
Do you know about the Unity "Console" window? You should be able to open it from Menu/Windows/Console. It will act as a debugger giving you errors and warnings both while pre-compiled and at runtime. If I misunderstood the question, let me know.
Recently, Microsoft Acquired SyntaxTree, the creator of UnityVS plugin for Visual Studio, so it is going to get released for free very soon. UnityVS is a must-have plugin for every Unity3D developer, due to it's productivity and the ability or debugging of Unity3D games in Visual Studio.
http://unityvs.com/
In MonoDevelop, there's a button near the top of the window that says "attach to unity". If you do this before you play your scene, any breakpoints set in MonoDevelop will halt the main thread there.
If you're just trying to inspect values, Debug.log(message) prints data directly to unity console.
Both of these can be used while in regular play mode.
Easiest way to debug is using Debug.log("");
but this does cost you your performance so how can you debug easier?
well here is the answer:
To start debugging, press your mouse to the far left edge of the editor (next to the line number) and a red dot will appear, you would have just created a breakpoint!
This will not do anything for now, however, if you now go to Unity and press play in your editor window something great will happen…
At the very bottom of the window, if you have the locals window open (if not, Go to View > Debug Windows > Locals), you will see all of the variables that currently exist in the local instance and their values at the time of the breakpoint being hit.
To continue the applications execution, just press the “Play” button in MonoDevelop.
Your script will continue its execution (and Unity’s editor will no longer be frozen). Of course in this instance, the script will hit the breakpoint again on the next frame. So just left click the breakpoint in MonoDevelop and hit the Play button again so it doesn’t execute the breakpoint again.
You can do more things with it for example:
With breakpoints, you can make them stop the application running when certain conditions are met. For example, imagine you want to check what the values are when the fSpeed variable reaches 10. To do that, press the Stop button in MonoDevelop, and Right click on your breakpoint, then press Breakpoint Properties.
Set the condition to “Break when condition is true” and set the “Condition Expression” to “fSpeed >= 10” and then press OK.
Re-attach the editor to Unity and press the Play button in Unity, when the condition is met the breakpoint will fire and stop the application.
A note about using Condition Breakpoints: They cause performance issues as it has to validate the expression each time it is run.
this should in general be better then debug.log(""); atleast if this is what you desire.
The best way using Debug.Log() for debugging in Unity if your problem is suitable to apply this.
I'm using the plugins UnityVS, which can debug Unity projects with Visual Studio.
Very convinient.
Have a google with UnityVS
You could check out using MS Visual Studio Community and getting the Unity integration they also provide on their website. I recently tried it and it's great, you get pretty much full debugging functionality using one of the best IDE available. Paired with Unity you can get some nice productivity boosts, not just in terms of debugging capabilities, but also in terms of feature set.
In case you want to check it out, here is a link to the Community version of the IDE: https://www.visualstudio.com/en-us/products/visual-studio-community-vs.aspx
Here is also a link to the Unity integraiton I mentioned: https://www.visualstudio.com/features/unitytools-vs
Hope it helps, a fellow developer converted me from Mono and honestly I couldn't be any happier with that setup (unless some IDE integrates the "make it work" button once and for all ;) ).
With Unity 5.5 visual studio tools are built in, you can attach unity and start debugging with a single click
i.e after Edit > Preferences > External tools > External script editor > Visual studio
There are two ways of debbuging in unity once is by Log which is console basically within Unity and the other is Debugger which is VS and Mono both supporting .
Yes you are right its very awfull process to check by debug point tha what is the value of a and b etc
so here is my opinion that use only what is best suiteable for you i mean you do not need of debugging point for just know the value of a and b just log it.
and when there is need for debugging point you already know the method.
You can use the Run button (looks like a play button in the top left) to connect to the Unity Editor for debugging, but if you're not connecting to Unity successfully this way, you may want to check that the appropriate plugin is enabled in your Add-in Manager preferences.
Windows:
Tools > Add-in Manager > Unity > Mono Soft Debugger Support for Unity
OSX:
Unity > Add-in Manager > Unity > Mono Soft Debugger Support for Unity
(Select and click enable.)
use debug.log("Message"); for debugging
Something I like to do too is making shortcuts for logging useful data within the Unity Editor. For example logging the current state of all my active achievements.
[MenuItem("My Game/Runtime debug/Achievement states")]
public static void LogAchievementStates ()
{
foreach (AchievementState achievementState in Data.achievementStates)
{
Debug.Log ("Achievement " + achievementState.name + " is at " + achievementState.completion + "%");
}
}
Doing this within an editor script will display a menu button to run certain actions.
I think that what the question is after, is a way to launch a "unity built game executable" and attach the debugger to it.
Something like...
creating debugging symbols with gcc, building the application with DEBUG enabled and launching the executable program with gdb to debug it. That way you can launch debugging sessions without using an IDE. But that's in C using gcc... in C# there is no need for debugging symbols for the attached debugger to see the code and it runs over a virtual machine.
There is an open conversation about how this can be done here:
https://github.com/0xd4d/dnSpy/issues/393
Some quick notes for someone not versed in virtual machine languages. C# produces an intermediate language when compiled. Contrary to C for instance that produces machine code, executed directly by the CPU. In the case of C# this intermediate language is call Common Language (because it is common for all .NET languages like VB.NET, C#.NET and C++.NET. This intermediate language is not executed by the CPU directly but by a virtual machine instantiated once per application or process, which is called the CLR (Common Language Runtime). This means that most of the time, if the variables and methods are not replaced by gibberish (which is called obfuscating), the program can be read directly by a debugger attached to the executable.
According to the conversation, the unity engine does not use the .NET CLR but a separate (potentially modified) CLR embedded to the engine. They do describe ways to do that but, I think its safer and easier to use the Unity Editor.
Unity is built around the editor anyway! For instance, within the editor context, you can change public variables and references while playing the game, which is not a "classic" programming approach. But it is a classic debugging approach.
Lastly, there are stuff like the threads of the program that are not open sourced, so I doubt that any external tool would be able to find its way around the code. Even if, it is pure Common Language, which I seriously doubt because if it was pure CL there would be no need for a separate (potentially customized) CLR to be including in the engine.
The whole misunderstanding in my opinion, is caused by the fact that the language that Unity is using, is not exactly C#, but a unity-variant that looks like C# and it may be compatible with C# but I do not know to what degree. So, the "CLR" you are programming in Unity is actually the unity engine itself. A "CLR" focused on rendering games in many platforms and not the classic C# CLR.
About the other answers:
- MonoDevelop lets you use breakpoints and preprocessor macros just as well as any other IDE.
- As for the text debugging using the log. Of course its possible but this is what one does when "real debugging" is not available.
tried visual studio? there you can attach the scripts to unity and debug them.
First you have to attach the C# code present in monodevelop or visual studio to the Unity debugger, than press the play button in the IDE monodevelop and than in last play it on unity.
You can just put some print() or something idono
Just try to open the C# scripts with Visual Studio you want to debug Use Visual Studio 2017 for this purpose and just start the project with debugger and apply breakpoints on your desired location and run the project . I think it will solve you issue and debug the desired piece of code
Unity documentation -- Debugging C# code in Unity provides the complete methods to debug the C# code in the editor and in the player.

Silverlight Won't Show Exceptions

I'm working on a project in Silverlight and somewhere an exception is thrown. I'm not concerned with fixing the exception... I just want to find it.
Instead of Visual Studio popping up and showing the the line where the exception happened, I instead get a little window labeled "Just In Time" which mentions an error 4004, a managed runtime error. It asks which debugger I want to use to solve the problem. But, it only provides one option: a new instance of Visual Studio. If I try to accept its proposal, the new instance complains that a debugger is already attached.
Why doesn't the instance of VS which built the program and is already running catch the exception and show me where it is?
That is strange behavior. The first thing I would do is change a few settings
Disable Just My Code
Enable native debugging
Break on first exception thrown
This should help you narrow down the place where the exception is occuring.
Disable Just My Code
Tools -> Options
Debugger
Uncheck "Enable Just My Code"
Enable Native Debugging
Right click on the project and select properties
Go to the Debug Tab
Check "Enable Unmanaged Debugging"
Break on first exception thrown
Debug -> Exceptions
Check "Throws" for Common Language Runtime Exceptions
Silverlight has a habbit of swallowing exceptions. I call this "silent failure" and have found it very expensive and frustrating. When working with Silverlight do everything you can do expose exceptions, e.g. binding failures.
Have a look here: http://msdn.microsoft.com/en-us/library/cc189070%28v=vs.95%29.aspx
Also there is a setting on elements to have them visualise binding failures but I forget what it is as I'm not working in Silverlight any more.
Looks like the problem is the type of debugging. In your project properties make sure you enable Silverlight debugging. In your website project right click, go to properties, then on the 'Web' tab at the bottom there's a section called Debuggers. Make sure that Silverlight is selected.
Sometimes the JS debugger is attached to the IE process, which means that there's a debugger attached, but it's simply not the debugger you want. I think this might be the cause of this problem.
Hope this helps.
Miguel
click debug, choose exceptions, mark common language runtime exceptions as thrown.
I had the same problem and it fixed the problem for me

Breakpoints, New Data Breakpoint in VS 2010 disabled

I have a nasty issue with an object being destroyed in a big project of which I cannot find the place where this happens. In Visual Studio 2008 I would have set a data breakpoint but when trying to do this in 2010 the option New Data Breakpoint is disabled. The project is running and a non data breakpoint is hit. What is going on here? I read about Managed Code. How can I find out if my project uses managed code and if yes, how can I avoid this?
When you attach to the process (or in your settings) disable Mixed Mode Debugging. In other words, make sure you have "Native code" be the only debugging option that's checked.
Just to gather the comment made by Eric H into a more complete answer:
Make sure the debugger is started in "Native code" mode.
Data breakpoints may not be set while the application is running. This means the application should be paused at another (function) breakpoint.

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