I am a beginner when it comes to coding, and I have been struggling with a very annoying problem this entire day. I hope you can help me relieve this awful headache.
My idea is to create a very simple app for my Mac, so I downloaded Visual Studio and Xcode.
I followed this tutorial from Youtube to get started, but halfway in the film I see that I am not able to get the same "outputs" as this Youtuber gets ( https://youtu.be/rj_n4W_mDN0?t=340 ). In my case it doesn't automatically provide "NSTextField*LabelInfo", but I can attach the button and label to the script and make them show when I run Visual Studio.
I am not provided this autofill either ( https://youtu.be/rj_n4W_mDN0?t=420 ) or the option of calling the "HelloPressed" function in Visual Studio.
Then I discovered that I have an error message in Xcode when I try to build it: "undefined symbol _main" (which the Youtube person doesn't have).
It also reads:
"Undefined symbols for architecture x86_64:
"_main", referenced from: implicit entry/start for main executable
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)"
I deleted my code and restarted the program, but the same message popped up. I deleted both Xcode and Visual Studio, and reinstalled it, but it still came up. This time I didn't add or do anything other than opening a new projects (in Cocoa app), and still I was greeted with this annoyance.
I see that my "Main.cs" in Visual Studio is not appearing in Xcode project (all the other ones are), but I don't know if this is relevant. I have tried to add different Frameworks to Xcode (AppKit), but I still receive this message. Maybe there is something I have to do in the Build section of Visual Studio, but I don't know what.
I have absolutely no clue what to do and how to proceed. I find it so strange and annoying that the Xcode gives me an Error without me doing anything else then starting up the program. My Macbook pro is very new so that cannot be the cause, the softwares are newly updated: Xcode 11.5 and Visual Studio 8.6.5 (build 23). I am programming in C sharp
I hope you are able to advice me in what to do. I am a beginner so I would appreciate easy-to-follow assistance or instructions.
Thank you very much,
August
Sorry I can't offer a definitive answer but hopefully the following will help you find your issue. I don't usually use VS for Mac and installed it just to see if I could figure out your issues. It is not as intuitive as one may like...
Visual Studio for Mac on both Mojave & Catalina does not work appear to work as the video you found seems to show.
Double-clicking on a .storyboard file generally seems to open the file in VS's XML editor rather than in Xcode. There might be a setting to control this somewhere. To open in Xcode right-click (or control-click) the file name and select Open With… -> Xcode Interface Builder in the menu that appears.
– Once over in Xcode you may find you have two open windows, one is just the .storyboard file and the other is a dummy Xcode project containing it. Close the first of these and just edit within the Xcode project window. If you don't do this you cannot create bindings between the controls and the source. If you look at the Xcode windows in the video you found you will see that when the bindings are being made it is in the project window, but there is nothing to show how/why that window opened up at the front.
Do not try to compile the "project" in Xcode. It is not meant to be compiled and appears to just be the bare minimum scaffolding required to enable VS to use Xcode for UI editing. All the errors you got are related to this.
Searching the internet for Visual Studio for Mac and storyboard files turns up plenty of hits and these files failing to open correctly seems a common problem from a scan of the titles. Do some research and you'll probably get it to work smoothly, but it does work as is albeit a little fiddly. HTH
I've been working on xamarin to build a crossplatform project on VS2017. I'm in the late phases of development and everything used to work fine. Couple of days ago while coding, I took a brake and updated windows. Since than my visual studio has gone "crazy" . Every time I deploy an application on a device and trying to debug it, it will only show a message in the stack trace and then it will crash my app.
This is what it shows :
Android application is debugging.
In this moment the app will reopen and than crush. It's a very strange behaviour. I of course tried different apps which used to perfectly work, and they have the same issue. I even tried it with a brand new application. Same thing. And of course the app works when I build it from my windows PC to an Iphone or iphone simulator. I can't wrap my head around this.
Has this happened to anybody lately? Is there a problem with the PC or a problem with the VS2017 ???
A little help would be very appreciated. :)
== edit ==
My VS2017 version is : 15.4.2 . Is there any known problem with this kind of version??
try to enable Exceptions
Debug > Windows > Exception Settings
Probably this can be a problem of the emulator. In short, get a fresh installed copy of the .android folder by installing vs on other pc, delete the current one, RESTART your PC and paste the copy to its folder.
To makr things more clear, I believe its good to share my attempts. What I noticed from my experience is, the emulators start behaving odd on your normal debug process. The reasons can be different, some of which were, according to my experience, sudden pc shut down, using large file size images as drawable backgrounds, closing emulator before debug was complete and so on.
Once such odd behavior happened to the emulator, I tried everything I could access online to reset the emulator or create a new one but none solved my problem, even reinstalling vs2017. Finally I was left with one choice which I still think is a foolish idea. Backed up and reinstalled windows, reinstalled VS2017 and other software I needed at that moment. When I was done with clean installation, before I started my work, I copied and backed up the .android folder (almost 10GB for the four default installed emulators) that is located in the user folder and continued my work as usual. And if the emulator fails again at anytime (like even in cases of black screen, being super SLOW, Launcher not responding...), I DELETE the current .android folder in the current user folder, make sure all of the emulators ARE NOT available for the debug option (replaced by start) in visual studio, RESTART the pc (important), copy your backed up .android folder and paste it back to your user folder where it was originally located.
Then you are good to go. I hope this will help someone.
I am trying to develop my first Android/iOS app using Xamarin, however every time that I try to create a new project and open up the Main.axml in the Resources -> Layout folders, I get an error stating that "Something went wrong"
Something Went Wrong
I have tried re-installing Visual Studio as well as Xamarin but I have had no luck. Any help is greatly appreciated!
Install the Android SDK. You can get it from here
If you have already installed the Android SDK, you might need to (Inside Visual Studio) go to Tools -> Options, in the left side on that new window that opens Expand Xamarin. Click on Android Settings and Make sure all the Locations are set for Java Development, Android SDK, and NDK Location. Point your Android SDK location to where you installed it.
so i downloaded monodevelop...and it installed xamarin studio 5.0.1...the gtkc# is working well...i made an app and run it...everything went well...when i tried to make an android app with c# thru new solution it said the "MainActivity.cs" couldn't be found.I let the default location in documents/projects and named the solution hello.I also have installed the android development add-in from add-in manager.I can't figure out what's the problem...also i had installed the android tools from eclipse.
I think it has something to do with the licensing, as XamarinStudio + Android / iOS is not a free product. I believe that the "re-branded-as-XamarinStudio" MonoDevelop available from the MonoDevelop website is simply missing the stuff needed to create these types of projects.
While I'd be interested in knowing why MonoDevelop has released a crippled (read broken) version of XamarinStudio, one can simply get the fully-functional "XamarinStudio" from the XamarinStudio website, and it will be able to create these project types without this issue (so long as you have a trial, or full license).
It will still be able to create other types of C# projects, just as MonoDevelop used to, as this whole thing is part of the process of moving away from the MonoDevelop name, and having a single product "XamarinStudio".
First of all I would like to say that I already tried all the solutions I could find on the internet, including Unable to Activate Windows Store App
I recently upgraded my Windows 7 machine to Windows 8.1 to be capable of developing Windows Store apps using Visual Studio 2013. When I open a blank project (Windows Store -> Blank App) and run it I get this error:
Unable to activate Windows Store app 'Package Name'. The App1.exe
process started, but the activation request failed with error 'The app
didn't start'.
See help for advice on troubleshooting the issue.
I already tried:
Reinstalling Windows (Clean install)
Reinstalling Visual Studio 2013
Installing Visual Studio 2012 (same error)
Deleting "bin" and "obj" folder
Cleaning the solution
Uninstalling the app from start menu
Creating a new project
Acquiring the license multiple times (the license is valid)
Making sure that app.config doesn't exist
Investigating the Windows Event Log which says
Activation of the app 'Package Name' for the Windows.Launch contract failed with error: The app didn't start..
but found nothing useful
Adding a new Windows user
Run everything as administrator
and at last, changing the desktop background :)
None of this did bring a solution. Does anyone have an idea what else could be the reason for this error?
Thank you.
I found a solution. The problem was that the drive I was working on was encrypted (TrueCrypt). Moving the output folder to an unencrypted drive solved the problem.
If switching from x86 to x64, make sure your Project Properties Platform Target and Configuration Platform are BOTH set to X64.Hint you need to change to x64 debugging in the Build menu/Configuration Manager dialog to get the Configuration Platform in Project Properties to update.
This caused the activation error problem to be resolved for me
HTH
Robert
I had the same Error and tried after loading the SQLite Package for WP 8.1 some things above:
not working:
Clean and Rebuild
Restart Computer/Phone
what did the deal (for me)
I put Platform Target under Properties -> Build to ARM instead of x86
Hopefully this might help somebody else facing this ridiculously informative Errormessage.
I had the same problem with Visual Studio Community 2015 while trying to debug an Blank App (Universal Windows) using Visual C#.
Visual Studio was installed on Disk C:(SSD), and Project files were placed on D:(HDD). I´ve created a Folder on C: Drive and placed my test project there.
After that Error messages gone.
If you are receiving this error and are developing for Microsoft Hololens:
You are trying to build to a device that is asleep. To wake your device, tap on the button on the back (on/off button).
Good luck!
I've tried all the solutions found on the net and none applied to my case, not even this one.
The only way I could make it work was changing the Package Name in the appxmanifest.
This made me think there must be some leftovers somewhere around with the old package name, that are either corrupted or inaccessible because of some permissions issues.
It might be just a coincidence but the problem appeared twice after I tried using the app verifier (appverif.exe)
Now I reassociated my app to a store app package and things seem to continue working...
In my solution, I have a non-UWP project (Multiplatform development) that builds with a different Solution Platform.
I was attempting to run the UWP project in Debug, but as the wrong Solution Platform.
Edit:
I also get this when I build my project for Any-CPU, instead of x64.
Ensure that ALL APPLICATION PACKAGES has "read" permissions on C:\Windows.
My organization's group policy likes to strip all permissions from C:\Windows, including the ALL APPLICATION PACKAGES group . By adding it back in and setting Read & execute, List folder contents, and Read, I'm able to run the app from Visual Studio without any problems.
See What to do if your Windows 8 Modern App fails to start for more tips, including this one.
I had the same problem in Visual Studio 2015 Update 3, Windows 10 Build 10586.494.
The error came up when trying to start any UWP app that I compiled without .NET Native Toolchain. With Native Toolchain enabled, the apps would start.
Installing a new (blank) app manually fixed the error for me:
Start VS 2015
File > New > Project.
Blank App (Universal Windows) Visual C#. OK.
Make sure to be in Debug config
Right click on Project > Store > Create App Packages
No. Next.
Select Debug for all architectures.
Create
When packaging is finished, open Explorer to the project path / AppPackages / [...]_Debug_Test
Right-click on Add-AppDevPackage.ps1 > Run with PowerShell
Follow the instructions
Start the installed app from Start Menu
I had the same problem a couple of weeks ago. A simple restart helped me out.
Also tried this one?: http://irisclasson.com/2012/11/04/problem-unable-to-activate-windows-store-app-the-app1-exe-process-started-but-the-activation-request-failed-with-error-the-app-didnt-start/
Hope its usefull to you
I managed to fix the same problem by rebuilding the solution. (In Vis Studio 2012)
I have tried many solutions and nothing worked. At the end what worked for me was to change the startup project to windows phone 8.1 and after it runs OK I changed it back to windows 8.1 and it runs OK. It works for me as I am making a universal app. Hope it helps anyone else.
I had the same issue with a Windows Store App after moving some files around. I ended up opening an older file (as Admin) to see if it would run and found that it did. I then returned to the file that would not and it ran also. I believe opening the older file (as Admin) reset the paths for development and the permissions. Hope this helps.
Same problem - moved my project from the TrueCrypt Partition and all was fine.
I had a similar issue, solved by choosing a new publisher certificate. And of course restarting Windows
I had same issue. Selecting proper Platform solved my problem. i.e. My application was selected to run under x86 platform, while my OS & SDK supports x64. Selecting x64 solved my problem.
I had the same problem on a UWP app when creating a package for Testing, but not when runing directly from Visual Studio 2017.
The solution was to select only the architecture that I am using to Debug the App, Instead of all options (x86, x64, ARM).
Here is the option choosed on Visual Studio
There are can be a couple of things that might be causing this problem.
Here are the trouble shooting steps that helped me out:
Step 1 : Check to see if running visual studio in the elevated mode (Run as an Administrator) helped solve the problem. (Sometimes, your folder permissions might get mangled due to various softwares that you might have install)
Step 2 : Delete all the bin and obj folders in your project and rebuild the projects in your solution manually.
Step 3 : Do a quick check of your System Type (x64 or x86 etc) and see if your project is targeted for the same.
Here is how to do know your system type: Win + R > cmd > systeminfo
If it says x64, then make sure to select the Solution Platforms (In visual studios top action bar) as x64 or so forth depending on your architecture.
Thats all I did to solve my problem.
I had unticked an option while trying to get debugging working prior to this error, the fix for me was to re-check the "Compile with .NET Native tool chain"
A rather niche situation and solution...
I was remote debugging a UWP app for a while successfully. After some reworking, I ran into this issue. In the main app project I had set the windows version compatibility accordingly (I am running the app on a Windows 10 IoT Enterprise 2019 device) but had forgotten to match those windows target and minimum versions for the Library Project that was in my solution.
After cleaning and re-deploying the solution (first uninstalling the app from the remote device), the problem went away.