DataTips appear broken in Visual Studio 2019 after attaching to a process when working on a 2nd display

Question

DataTips appear broken in Visual Studio 2019 after attaching to a process when working on a 2nd display

Jeffrey O 11

small program, test.c, which reads:

include <stdio.h>

int main() {
int x,y;

x = 1;
printf("hello, world from pid %d\n",GetCurrentProcessId());
Sleep(30*1000);
for (y=x; y < 10; y++)
printf("%d ",y);
printf("\nThat's all folks\n");
}

and I build it with "cl test.c /Zi", if I run it in VS2019 with "devenv /debugexe test.exe" then I can hover over the variables x and y and see their values (hovering over the printf function displays info about it as well). However if I run it from the console prompt and then start VS2019 as an adminstrator and use Debug->Attach to attach to the process and then Debug->Break, hovering over things no longer displays any information. If I do the same thing in VS2013, hovering over the variables displays their values.

This is using a laptop with an external monitor attached and with VS 2019 on the external monitor. If I move VS2019 to the laptop display, then the datatips show up and I can see the value of variables when I hover over them.

The original problem (at our company) was reported by someone running Windows in a VM on OS/X. I'm running Windows on "bare metal" (Dell laptop) but it seems in both cases, there's some interaction with the display going on.

VS2013 works properly in both situation (either of my screens or in the VM under OS/X).

David Lowndes 4,726 Reputation points

2021-01-08T08:48:06.377+00:00

Do other aspects of debugging when you use attach to process also not work, or is it just the datatips that don't work?
Jeffrey O 11 Reputation points

2021-01-08T13:03:24.793+00:00

Just datatips

5 answers

Your answer

David Lowndes 4,726 Reputation points

2021-01-08T08:48:06.377+00:00

Do other aspects of debugging when you use attach to process also not work, or is it just the datatips that don't work?
Jeffrey O 11 Reputation points

2021-01-08T13:03:24.793+00:00

Just datatips

Answer 1

@Dylan Zhu-MSFT Ok, I think I've found the cause of the trouble - it relates to the scaling settings for the displays. My 2 monitors have different resolutions. My laptop display is 3840x2160)and my external monitor is set to 2560X1440 so I have the scaling set to 100% on the external monitor and at 200% on the laptop display (I extend my desktop across them - the laptop is display #1).

If I set the scaling factor on my external display to 200% to match the primary display, then the datatips start appearing as I hover over things. I bet the presentation layer code is picking up settings from the primary display on the system rather than the current display it is running on (or something like that).

This problem started from someone running VS2019 on a MacBook in a Windows VM and I suspect there is some similar display setting mismatch in that environment.

None of this happens in VS2013.

After repairing the install I noticed a problem with the menus related to setting options (I had to reset my debugging symbol setting). Under Debug->Options and Settings as I click through the left hand column of options, sometimes the window on the right doesn't update or sometimes it displays as blank. Again, if I move VS2019 to my primary display, then it works fine. Here's what one of them looks like where the right hand window is blank:

If I click somewhere else in the left panel and then come back to this one, it might show up, or it might take a couple of tries. In VS2013, this problem doesn't exist.

Hedman, Annette 6 Reputation points

2022-06-03T07:51:28.213+00:00

Thank you, this answer helped me!
Changed my display scaling so they were alike on both screens, and voilá, there I could see the values again!
Hopefully it also helps the problems I had with file content sometimes not showing too, as described above.

Answer 2

Dylan Zhu-MSFT 6,426

Hi JeffreyOrlin,

Please try to set some breakpoints in your code, which will help break the debugger when the code will be executed.

Best Regards,
Dylan

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Jeffrey O 11 Reputation points

2021-01-08T13:13:36.763+00:00

I'm attaching the debugger to a running program (its in the Sleep(<30 seconds>) and then I use Debug->Break to stop execution. No need to set a breakpoint to get it to stop execution...

This works if I use VisualStudio 2013, it does not work if I use VisualStudio 2019.

That said, I tried what you suggested.
In this screenshot execution has stopped at the breakpoint on line #10 (I set the breakpoint after attaching and let it run until it was hit). I was hovering over the x on line #6 (the cursor doesn't get captured in the screen shot). You can see the green 'runto' icon at the end of the line but no datatip pops up

It should be pretty trivial for anyone to reproduce this behavior. Are you saying that when you try it, the datatip pops up and shows you the value of x?
David Lowndes 4,726 Reputation points

2021-01-08T14:21:19.737+00:00

Check the call stack when you've broken execution - if you're not "in" your source, that would explain why it's not working.
If you step out to your module (Shift+F11), see if the datatips work then - they do for me.
Jeffrey O 11 Reputation points

2021-01-08T14:58:58.99+00:00

The call stack shows I'm in my program.

One question that might make a difference.

When I run VisualStudio on the opening screen, I select "Continue without code" to get to the screen with the Debug menu item that I then use to attach. What do you select after you start VisualStudio?
David Lowndes 4,726 Reputation points

2021-01-08T16:17:58.257+00:00

Starting without opening the project doesn't make any difference for me, it still works. I'm using the 16.9 preview 2 version.

Answer 3

Maybecompletelyw_0 281

Sorry cannot reproduce with VS Version 16.8.3.
With my 'Debug->Options...', e.g. looks like this, when in
ntdll.dll!_NtDelayExecution@8 ()

Jeffrey O 11 Reputation points

2021-01-08T14:52:10.773+00:00

Just to confirm, you got to this point by attaching the debugger to a running process?

That's great to know as it means there must be some way for me to get it to work. I'm also running 16.8.3.
This is my set of installed products (from Help->About). I wonder whether I'm missing something
(had to paste as an image to stay within the 1000 character limit)

Answer 4

Yes, I am attaching, how I start VS does not make a difference.

Microsoft Visual Studio Community 2019
Version 16.8.3
VisualStudio.16.Release/16.8.3+30804.86
Microsoft .NET Framework
Version 4.8.04084
Installed Version: Community
Visual C++ 2019 00435-60000-00000-AA572
Microsoft Visual C++ 2019
ASP.NET and Web Tools 2019 16.8.554.20160
ASP.NET and Web Tools 2019
C# Tools 3.8.0-5.20604.10+9ed4b774d20940880de8df1ca8b07508aa01c8cd
C# components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used.
Debugging Tools for Windows 10.0.19030.1000
Integrates the Windows Debugger functionality (http://go.microsoft.com/fwlink/?linkid=223405) in Visual Studio.
IntelliCode Extension 1.0
IntelliCode Visual Studio Extension Detailed Info
Microsoft JVM Debugger 1.0
Provides support for connecting the Visual Studio debugger to JDWP compatible Java Virtual Machines
Microsoft MI-Based Debugger 1.0
Provides support for connecting Visual Studio to MI compatible debuggers
Microsoft Visual C++ Wizards 1.0
Microsoft Visual C++ Wizards
Microsoft Visual Studio VC Package 1.0
Microsoft Visual Studio VC Package
NuGet Package Manager 5.8.0
NuGet Package Manager in Visual Studio. For more information about NuGet, visit https://docs.nuget.org/
ProjectServicesPackage Extension 1.0
ProjectServicesPackage Visual Studio Extension Detailed Info
Test Adapter for Boost.Test 1.0
Enables Visual Studio's testing tools with unit tests written for Boost.Test. The use terms and Third Party Notices are available in the extension installation directory.
Test Adapter for Google Test 1.0
Enables Visual Studio's testing tools with unit tests written for Google Test. The use terms and Third Party Notices are available in the extension installation directory.
Visual Basic Tools 3.8.0-5.20604.10+9ed4b774d20940880de8df1ca8b07508aa01c8cd
Visual Basic components used in the IDE. Depending on your project type and settings, a different version of the compiler may be used.
Visual Studio Code Debug Adapter Host Package 1.0
Interop layer for hosting Visual Studio Code debug adapters in Visual Studio
Visual Studio Tools for CMake 1.0
Visual Studio Tools for CMake
Windows Driver Kit 10.0.19030.1000
Headers, libraries, and tools needed to develop, debug, and test Windows drivers (msdn.microsoft.com/en-us/windows/hardware/gg487428.aspx)

Answer 5

Jeffrey O 11

Ok, turns out its got something to do with the display.

I'm running a laptop with an external monitor. If I move the VS2019 window to my laptop display, then I can hover over things and the info pops up (function info, values of variables, etc). If I move the VS2019 window to my external monitor, they do not. So its something about the combination of attaching to a process and having the VS2019 window on my external monitor which causes this not to work.

This was originally reported to me by someone I work with running Windows in a VM under OS/X (where it used to work with VS2013).

Dylan Zhu-MSFT 6,426 Reputation points

2021-01-11T09:00:45.62+00:00

Hi @Jeffrey O , could you see the values in Watch or Autos window while debugging?
Jeffrey O 11 Reputation points

2021-01-11T13:06:22.083+00:00

yes. everything seems to be working except for the pop up windows as you hover over something. If I move the VS window to the primary display, then the pop up windows start appearing again.
Dylan Zhu-MSFT 6,426 Reputation points

2021-01-13T08:11:23.293+00:00

Hi, @Jeffrey O , I have tested it in a laptop with two monitors, and the data tip can work as normal. Maybe you can try to repair visual studio.

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DataTips appear broken in Visual Studio 2019 after attaching to a process when working on a 2nd display

include <stdio.h>

5 answers

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