Develop Reference

Getting app to install emulator in a xamarin project without having the source code

I have looked through the Microsoft documentation but everything seems to want you to run everything with the development code. I used a bitbar tutorial to help start my C# xamarinui test framework. I have the emulators working I just want the apk and ios apps to install as the first test. I know how to drag and drop and put the app on the phone manually. I am looking for a way to get the app to install and launch through test code or by some operation. I do not have access to the source.

Only for the Android case, google for the apk, usually they are available on sites like apk pure etc. If the apk has executables for x86 inside you could install in on android simulator using just drag and drop.
For iOS this seems not possible as the installer has to be signed with appropriate profiles that only app developer has in his possession.

Xamarin Won't Build on Physical Devices

I'm building a Xamarin app, and, so far, I've been able to build without issue on the iPhone Simulator, but I haven't been able to get the app to launch successfully on a physical iPhone device. In the past (about a month ago), the app was working fine on the same device. Here's some background on the specifics:
I develop my Xamarin code on my Windows machine, which is linked a remote Mac (hosted by MacStadium, a third-party hosting service).
My test phone is an iPhone 5c running iOS 10.3.3
To deploy to my iPhone, I build my app in Release mode in Visual Studio, upload the code to a third-party app installation service, Installr, which hosts the IPA file and assists with the installation of my app on the physical device. I've never had an issue with Installr and have no reason to believe that this is the source of my problem.
Since the last time the app worked on the physical device, I updated Visual Studio to version 16.3.2 and updated Xamarin. Here's the Xamarin Specs:
Generally, what happens, is that I download and install my app on the iPhone without any issue. However, when I click on the app, the splash screen loads for about 5 seconds, a white screen briefly appears as follow, then the app crashes.
I've seen several related articles on StackOverflow and other sources on the internet, but none of the proposed solutions see to work for me. For example, I've tried adding [assembly: XamlCompilation(XamlCompilationOptions.Compile)]
to App.xaml.cs with no luck.
I've also played around with changing the CSProj file settings to compile for various combinations of ARM64 and ARMv7. Changing this didn't help either. I've tried changing the linker behavior to "Don't Link" from "Link Framework SDKs Only", and I get an error message stating that the native code is too large for 32-bit architectures. I would compile for only 64-architectures to get around this error, but I believe that the iPhone 5c uses a 32-bit architecture.
Here's what my iOS Project's CSProj file looks like currently. I've tried checking just about all of those checkboxes with no luck:
I'm stumped as to what this could be. Any suggestions would be greatly appreciated. To further complicate things, I haven't been able to get a good log file from the iPhone. Since the Mac is remotely hosted, I can't plug my phone into XCode to pull the logs that way. Does anyone have a reliable solution to get log files another way?

It looks like upgrading solved the problem. Visual Studio was updated to Visual Studio to 16.3.5 from 16.3.2. XCode on my Mac was updated to Version 11.1. After these updates, Visual Studio performed an update while connecting to the Mac remotely.

App crashes after installing a Xamarin-Forms app

I have 3 self-written apps on my phone. 2 written with Xamarin.Android and one written with Xamarin.Forms. But there is a big problem. It always work only 2 or 1 app depending on which of the 3 apps was installed last. If one of the two Xamarin.Android apps was installed last, then both Android apps work. The Forms App, however, crashes immediately. Same the other way around. If the Forms app was installed last, it works fine. The two Android apps crash immediately.
Is there any reason for that? Are the frameworks not compatible?

I had the same problem trying to install the apk from Debug folder.
Steps that worked for me:
- Disable "Use Shared Runtime"
- In Advanced Settings, Select supported architecture
Check the screenshot if not clear

If you are deploying a debug apk into the same device, with different Runtimes, when the apk is installed will remove the previous / override. So, you will need to: disable Shared Runtime, or make sure the dependencies are all the same in all the applications

If you are using visual studio then Check "Application output" with release on device.
In Application Output you can see if any exception is causing problem..

Force to update apk on playstore

In Xamarin Form mobile development, I created one apk and uploaded on Google Playstore.
Apk current version = 12;
Apk in mobile =11;
I want to compare my installed version of apk(11) with current version of apk on Playstore(12) and want to force to update apk.
I got coding for find installed version of apk by
Context context=this.ApplicationContext;
int code = context.PackageManager.GetPackageInfo(context.PackageName, 0).VersionCode;
How to find the current version of apk on playstore using xamarin c#. Thanks advance.

There is no official google api to get the version number of your app from playstore. Programmatically check Play Store for app updates
To achieve this you can maintain a table in your server and whenever the user logs in you can check the current installed version with the version number in your server and if it does not match then call an intent to the playstore.
OR
Android programmatically update application when a new version is available

Xamarin C# Cross Platform Application

I am new to using Xamarin and have always used Visual Studio, however I now require to develop a desktop application which will run on both Mac and Windows, OR at least a package which will let me package for both.
I have created a GTK 2.0 Project, connected to a MySQL database etc and all is fine, however I can only see options to create a .exe and no .dmg file for OS X but the debugger lets me run it on my Mac.
Does anyone have any ideas or pointers?

We use Xamarin.Mac to enable us to develop a Windows and Mac client using c#.
We chose to re-build the core code in Xamarin Studio and use interfaces to abstract the OS dependent code.
We share 90% of our code in the Xamarin.Mac/VS solutions.
Do let me know if I'm helping... if so I can provide more detail if need be.

Check the following link on how to create an .app bundle with Xamarin:
How to set Xamarin MonoMac project so its build outputs .app package instead of .exe?
An app bundle is basically a special kind of folder structure that contains all app data, including e.g. graphical resources, configuration files, localisations, etc...
A .dmg file is used for distribution and can be created using other tools like Apple's own Disk Utility, once you've created the app.