I have an app in Xamarin that I want to test on a physical IPhone (normally I test it on Android). I'm connected to a Mac, the development certificate is working and everything is deployed to the point that the app is actually installed on the IPhone itself. The issue however is that when I press the icon to start the app, it tries to start it and then is closes right after that (like it crashes or something).
I'm using Visual Studio for Windows, and it is stated that: "XAML Hot Reload encountered a problem and failed to start. Verify the Mono Interpreter for is enabled in the project settings, clean and rebuild the solution.". Mono Interpreter is enabled, I cleaned the solution and rebuild it multiple times. There are no errors given.
The app that is installed now shows the Xamarin icon and Xamarin splash screen (so not the custom one I designed). I don't mind that, but I'm not sure if that has something to do with this.
Does someone know what is wrong here and how to fix it?
Visual Studio for Windows version 17.4.1
iOS version 15.5
Note: this issue is only with the development and deployment directly from Visual Studio from Windows. When the app is distributed to the users (in App Center) the app works as it should.
In short: I am unable to run my app in the iPhone Simulator. There is no "Play button" (the triangle), only a Debugger button (hammer):
As you can see above I have "Generic Simulator". When I click on it, there is no list of various iPhones/iPads to choose from:
If I choose Android, I am able to run the app:
I have XCode installed. I ran XCode once.
I also installed the Command Line tools.
I created a new Xamarin Forms App:
Here are my iOS build options:
I am able to run the Simulator separately:
Creating an App in XCode and running in the Simulator works:
info.plist:
Prefrences -> SDK Locations -> Apple
Build -> Configurations:
Here is the kicker though. If I run a Xamarin App on my Windows machine using the iPhone Simulator on the Mac, it works!
What do I need to do so I can run my app inside the Simulator vis Visual Studio for Mac?
Few options you can worth to check. #WorldOfBasti suggested options plus following.
Configuration
Right click on the solution -> options -> Configurations -> Configuration manager -> ProjectName.iOS with Debug|iPhoneSimulator should be checked or if configuration "ProjectName.iOS with Debug|iPhoneSimulator" is not available then add this from General tab
Apple SDK path
Check Apple SDK path is set properly (Preference -> SDK Location -> Apple). It should have green tick mark with Xcode version and SDK path location.
Minimum system version (Deployment Target)
Change Deployment Target to minimum version (ie, lower than your simulator version)
Switch debug <-> release
Today I have also faced same issue which you are facing. I have switched debug to release, iOS to Android. Then reverted back to iOS and debug from the top device selection status bar. Then Simulator option was appearing. So, might be UI updated issue in Visual studio for mac. Please give a try.
I assume that you tried the basics things like restarting your Mac, etc. So here are a few things, that might solve your problem:
Check your build configurations, here is a good video
Close VS for Mac, start Xcode and create a test project which you run on a simulator. If it works try again in VS for Mac
Close VS for Mac, goto Xcode -> Preferences -> Accounts and download the manual profiles of your developer account. Try again in VS for Mac
Clean your project: In VS for Mac, goto Build -> Clean All. Then Close VS for Mac, goto your project folder and delete in "yourprojectname" and "yourprojectname".iOS all bin and obj folders. Try again
If all of this doesn't work, I would try to reinstall it (if you have any important projects, make a backup):
Uninstall VS for Mac and Xcode
Install Xcode again from the App Store
Install Visual Studio for Mac
Hopefully it works..
Looking at the Visual Studio for Mac logs, specifically the IDE log, I found this line ... 'The target name of simulated device could not be added because it's already cached'.
You are welcome to read through all of this ... but you may just want to go down to the Addendum 2 (final?) and see if that works for you ... it ends up being simpler and quicker than anything else I have found.
So, at first, I started clearing the cache with a 'xcrun simctl erase all' command from Terminal, and when I started Visual Studio for Mac I could run a Xamarin App, but launching the simulator took quite a bit of time.
So hare's something I found works that you might want to try ...
Close iOS Simulator on Mac (if any).
Close ALL copies of Visual Studio that are connected to the Mac ... either on the Mac itself or on another computer connected to the Mac (if any).
Start Visual Studio for Mac.
If you can't run a Xamarin App, Close Visual Studio for Mac.
Launch the Simulator manually (I have it in the Dock, so I just click it) ... wait for it to fully startup.
Now close the Simulator (from the Simulator menu).
Now restart Visual Studio for Mac.
If you still can't see the simulator devices to run on ... try the above steps one more time (this time you should only have to close Visual Studio for Mac followed by manually starting the Simulator, waiting for it to start, and then quitting the Simulator and finally restarting Visual Studio for Mac).
It still isn't great, but this has (so far) always worked for me. And the Simulator starts up substantially quicker then if I did a 'xcrun simctl erase all' command from Terminal.
Addendum: Most of the time the above works. But occasionally I still have to clear the cache from the Terminal with 'xcrun simctl erase all' command.
Also: I have also found (although maybe it's just my imagination) that clearing out the Visual Studio for Mac temporary .binlog files that are written in the 'T' folder will sometimes fix the problem (if you look at an IDE log from Visual Studio for Mac; right after the 'The target name of simulated device could not be added because it's already cached' message, you should see some .tmp files being created. The directory where they were created is the 'T' folder I'm talking about). I sometimes delete the tmp*.binlog and tmp*.tmp as a last ditch effort before using the 'xcrun simctl erase all' command to try to get back to where Visual Studio for Mac will see the iOS Simulator Devices.
Finally: This is really starting to feel like a bug in Visual Studio for Mac startup (or possibly during a iOS project load). The reason I say that is I can ALWAYS see the iOS Device list from Visual Studio for Windows (as long as I can connect to the Mac). In addition, I can leave Visual Studio for Mac running (even hidden) and test an app on the iOS Simulator from Windows, then, leaving the iOS Simulator Running on the Mac, run an App on Visual Studio for Mac. If there really were a 'caching issue' with the Simulator it seems to me I should have problems running anything on the Mac after using the iOS Simulator from Windows, but it always works. For now, I'm working on a single Xamarin Project on the Mac (and I don't use the Mac for anything else), So I just let Visual Studio for Mac 'open at login' (Dock setting) and automatically 'load previous solution on startup' (Visual Studio for Mac setting), hide Visual Studio for Mac (Dock Setting) and if I need it, Visual Studio for Mac is already loaded and able to see iOS Devices to run Apps on with a quick click on the Dock Icon.
Addendum 2 (final?): I have now found that if I just close a solution that I have open that shows 'Generic Simulator' and re-open it without exiting Visual Studio for Mac (sometimes I have to do it multiple times ... I think I've counted up to 5 times before it finally worked), it will start showing the device list and I can run the iOS app in the Simulator. I don't even have to close the Simulator if it's already running, which saves a bunch of time.
It still feels like a bug to me, I don't see why I would have to close/open a solution multiple times to get the iOS devices listed and be able to run an iOS app. What really gets me is if I reboot the Mac, don't open the Simulator and start Visual Studio for Mac, then open a solution, I still have to go through the close/re-open solution steps... sometimes more than once. The simulator is not set to auto start or anything like that. But, at least, it's getting simpler, and takes less time, to get to a point where I can run an iOS app.
I was running my console programs on mac without any problems and getting output in the console window a few days back. Now my unity window was open when I opened Visual Studio for running a console application (which I took from recent projects) and my tools to run or debug was gone. I clicked run from the menu but nothing is happening. I clicked run - start debugging I am getting an error like this
A ӳcriptӠcan״ go after this identifier.
I updated my mac to latest version - mac OS Catalina 10.15.2 - recently.
The above image is what has happened.
A few days back my tool set view was similar to the image shown below.How to see the tools again.
I also tried this option - another answer options was checked.
I installed the mobile development option for Visual Studio 2017, and created a new mobile app (Xamarin.forms) in the blank app template.
I tried to run the app, but I got the message The ADB binary found at is obsolete.
I downloaded the update from the SDK manager, and the message was gone, but now when I try to run the app, the emulator shows a black screen for a few seconds, and then the status strip shows the message Deploy canceled, and the emulator closes.
How can I fix it?
The error message is vague, you'll need to provide more information if you want someone to answer this.
To do so, you want to enable the diagnostics output in VS:
Here is a couple of things you can do in the meantime:
run VS as administrator
clean your project
go to the project folder and delete all the files under /bin and /obj
rebuild the project
Then try to deploy your application
The running process failed now because of deployment errors (after I did what Guillermo Gerard suggested):
I created new blank app in xamarin and i didn't change anything in code view.
When I try to run app. Emulator works good but app doesnt run in emulator. I am using VS 2015 Enterprise Version:14. My operating system is Win10 Enterprise
-VS
Right mouse click on solution. Select Configuration Manager. Select Deploy.
Sometimes it gets stack (check green bottom bar in visual studio). If green bar stays full and doesn't go away restart emulator.
Another reason can be that there is no MainLauncher Activity is defined.