Develop Reference

Hololens: no debug output in Visual Studio 2017

My task is very simple, I put in the Main method two lines:
Debug.Log("App START Debug.Log");
Debug.unityLogger.Log("App", "START Debug.unityLogger.Log");
and want to see these logs in the output if the app is running. If I set the run option as Releasethe app starts, but I don't see these logs. If I set the run option as Debug and try to start, I get an error popup:
Unable to activate Windows Store app ´Template3D_pzq3xp76mxafg!App´
and the app doesn't start at all.
EDIT: according to comment of #Perazim, I have also tried:
System.Diagnostics.Debug.WriteLine("App START Debug.Log");
No effect in Release and Debug mode.
EDIT 2:
System.Diagnostics.Debug.WriteLine("App START Debug.Log");
works, if I put it in other methods, but doesn't work in the Main() method.

Debugger.Log for the output to debugger. Debug.WriteLine prints to listeners. If there is no listeners, it will not work.

My application stopped writing output to the output window with the System.Diagnostics.Debug.Writeline in debug mode. This all happened after the latest Microsoft Updates.
I created a new application just to see if it was my current application, and the new application would not write to the output window either.
Then I decided to right click on the Output Pane in Visual Studio and what do I see, Program Output unchecked.
I checked this and my Debug.Writeline works again.

In unity you can use/see debug.log(); in Visual Studio you need to use Console.WriteLine();

SSDT SQL Server Debugging Doesn't Hit CLR Breakpoints

I applied the SQL Server Data Tools patch to Visual Studio 2012 (Premium) and created a SQL Server CLR user-defined function project in C#:
public partial class UserDefinedFunctions
{
[Microsoft.SqlServer.Server.SqlFunction]
public static SqlInt32 Add42(SqlInt32 in_param)
{
SqlInt32 retval = in_param + 42; // Set break point here.
return retval;
}
}
In the SQL Server Object Explorer pane, I right-click on the newly published UDF and select "Execute Function..." I am prompted to supply a sample input value, and Visual Studio then publishes the function (again) to my local 2012 SQL Server and generates a script that looks like this:
DECLARE #return_value Int
EXEC #return_value = [dbo].[Add42] #in_param = 5
SELECT #return_value as 'Return Value'
GO
... and executes it, returning the expected result of 47.
If I now put a break point on an executable line in my CLR UDF C# code, right-click the UDF function in SQL Server Object Explorer, and this time select "Debug Function...", I land in a debugger for the generated SQL test script. I can step through the SQL statements to the end of the script, which returns the correct result, but the breakpoint in my C# code is never reached in the C# debugger.
The terminology for this feature seems misleading. To any programmer, "debugging" a function means stepping through the executable lines in the code of the function itself. Simply generating a SQL test harness that calls my compiled function and gets back the result is just "testing" the function. At most, the only thing being "debugged" is the tool-generated test itself, because you can't "Step Into" the CLR code. The only option is to "Step Over" it.
So how do I get Visual Studio to actually debug, and hit the breakpoint in my UDF C# code?

Okay, I finally figured this out. To debug SQL CLR code in VS 2012:
Create a SQL test script that calls the UDF, sproc, or other CLR object.
(You can do this by using the "Execute Function" or "Debug Function" options in the
Server Object Explorer, as described in the question.)
Save the generated script. (It will be called something like
"SQLQuery1.sql" by default. You may wish to give it a more
meaningful name.)
In Solution Explorer, right-click the UDF (or other CLR type)
project, and select "Properties".
The project's properties tab will open. On the left, select the
"Debug" category.
In the "Start Action" subcategory of the Debug panel, select the "Startup script:"
radio button. This will enable the associated dropdown so that
you can specify the .sql script created in Step 1.
Save all, toggle a breakpoint on an executable line of your C# or other .NET language
code, and press the debug button.
NOTE: You may now get a dialog telling you that "Windows Firewall has blocked some features of this program." I checked the boxes to allow access to domain and private networks.
Proceeding now should cause your breakpoint to be reached.

For Visual Studio 2015 + Update 2:
In SQL Server Object Explorer pane, right-click on the server and select "Allow SQL/CLR Debugging":
In Server Explorer, right click on the function you want to debug, and select Execute:
It will generate the code for you. Select Execute with Debugger:
You can then place a breakpoint in your C# code, and it will hit it.
It will ask to open a port in your firewall, and it will ask to attach to SQL Server.

I do not know if SSDT changes this, but in VS2008 I debug a .net UDF as follows:
I deploy it to my local SQL server,
then I attach VS to the SQL Server process (Menu Debug/Attach to process/sqlserver.exe, if SQL Server is running as a service it requires that VS was started as administrator).
Then execute some SQL code calling the UDF, e. g. in Management Studio. Maybe this will work from SSDT in VS 2012.

The patch you applied may install VS items which are not current with the Visual Studio Quarterly update. I recommend that you now apply the latest Visual Studio Quarterly Update for VS 2012.

Microsoft Visual Studio 2012 cannot set breakpoint in c# file

I have Microsoft Visual Studio Professional 2012 installed, version 11.0.60610.01 Update 3.
When debugging a c# (.cs) file Visual Studio gives me the following message when I try to set a breakpoint:
"A breakpoint could not be inserted at this location".
I get this message even when trying to set it on a line within a method. But in a .vb file for a Visual Basic app, I can set a breakpoint.
I am wondering if anyone has any suggestions to resolve this or if I need to reinstall visual studio.
Thanks

Maybe I'm too late for this question but here it goes anyway,
BUILD > Clean Solution
BUILD > Build Solution

I have encountered a similar issue and I resolved it by exiting Visual Studio and deleting the .suo file from my solution folder.
This file is recreated when you open the project again and it is not harmful to delete it.
The .suo is used for storing the layout of your solutions, the breakpoints you've set, the tabs you had open, etcetera.
I am not sure why this worked but my logic was that Visual Studio thought I was trying to place a breakpoint in a location different to where I was actually placing it.

I was finally able to find a solution for this. I had to do a repair on my Visual Studio 2012 instance through the control panel -> Programs and Features, right clicking on Microsoft Visual Studio Professional 2012, and selecting change. In the Visual Studio window I then selected repair.
As part of the repair process, I also had to download web deploy located here: http://www.microsoft.com/en-us/download/details.aspx?id=4148 and point the visual studio repair process to the .msi file when it said it couldn't find the web deploy package and could not download it from the internet.
I also had to implement the fix indicated in the following stackoverflow question: Plain C# Editor in Visual Studio 2012 (No intellisense, no indentation, no code highlighting)
Now I am able to debug applications as expected.

Well, sheesh...for people as dumb as me, here's one more thing to consider:
You can put breakpoints on the curly braces at the start or close of a method, and you can put breakpoints on any line that is doing something (e.g. assigning a value or calling a method). However, you can't put a breakpoint on a line that is only declaring a variable or otherwise "doing nothing."
E.g. I had a method:
public IEnumerable<SomeObject> GetList()
{
int distance;
var otherVar = SomeValue;
}
I was trying to put the breakpoint on the first line with int distance;, which is something that works fine in other IDEs, but that doesn't work in VS. I had to go up to the brace or down to the next line with the assignment in order to get the breakpoint to set.
5 minutes of my life wasted, that I'll never get back, trying to debug a non-issue ;-p

VS 2017
I had this, I was missing an ; inside a for loop

If there is no instructions to execute on a line, VS refuses to set a breakpoint an offers no reason. EG
string str; //Cannot set breakpoint
string str = ""; //Can set breakpoint

Attach debugger onto another Visual Studio instance

I'm doing some visual studio extension development in Visual Studio 2010.
It would be useful to debug while developing so I have it configured to open another instance of VS when debugger for F5 ( http://donovanbrown.com/post/How-to-debug-a-Visual-Studio-Extension.aspx). This all works fine but is there a way to attach a debugger to an existing instance of VS2010, I have tried and the breakpoints aren't being hit. There are no errors but wondering if there is a way?
I should add I do know how to attach to a debugger and I have used it before to attach to ASP.net code.

Under Debug there is a item called Attach to Process. This will do exactly what you want it to do.
Use the Title column to tell which instance of devenv.exe you want to connect to (notice that I started the attach on BinaryFileSearch, but I am attaching to FixClientNoteRTF).
It does not let you attach to yourself because if you hit a breakepoint the UI would stop responding and how would you tell it to step or continue?

OK managed to solve it.
What I was doing was when opening an instance of Visual studio, following the usual method, i.e. open a normal instance ( devenv.exe).
What you have to is open a experiemental instance, using the parameters ( cmd line mode):
/rootsuffix Exp
Then use the attach to debugger mode to attach to this instance.

How to start a child process in the same Visual Studio debugging session as the parent, programmatically?

When running a process under the debugger, I would like to start a child process in the same debugger.
Currently, I use
Process.Start("sample.exe");
I want it to be something like this:
if (Debugger.IsAttached)
// start "sample.exe" in the same debugging session
else
Process.Start("sample.exe");
I could pass a flag to the child process that instructs it to call Debugger.Launch(), but that won't catch start up errors, and it results in a debugging session where some features are not enabled (such as edit and continue, etc). It's preferable to have the debugger launch the process directly.

You should attach debugger to process you are starting. This could be done:
Manually from Visual Studio after starting "sample.exe" select it menu Debug > Attach to process..
Programmatically attach debugger inside "sample.exe"
Attaching to a Process using VS.NET Automation Model
UPDATE: You can setup windows environment to attach debugger every time "sample.exe" starts: Launch the Debugger Automatically (you will need to call Debugger.Break anyway)
Some external tool maybe
Here is code for "sample.exe" to attach debugger:
if (!Debugger.IsAttached)
Debugger.Launch();
Debugger.Break();
You should pass some parameter to "sample.exe" to verify if you need to attach debugger.
Process.Start("sample.exe", "Debug=true");

you can change the properties of your solution to start multiple apps.
an explanation is here Run Multiple projects
The MSDN article is here MSDN Article on running multiple projects

Assuming that sample.exe would be the host for code you want to debug, you can use project properties -> debug settings - choose action as an external program and provide path to sample.exe. The VS will start this executable and attach the debugger to it.

Visual Studio Debugger Team created an extension that does that automagically:
https://marketplace.visualstudio.com/items?itemName=vsdbgplat.MicrosoftChildProcessDebuggingPowerTool