I am having difficulty getting my Monodroid application retrieve a location when I run it in an emulator. My code looks something like this:
LocationManager locationsManager = (LocationManager)threadSurfaceView.Context.GetSystemService(Context.LocationService);
location = locationsManager.GetLastKnownLocation(Android.Content.Context.LocationService);
However, this always seems to return null. Do I have to configure the emulator in some way so that it has a locaion service and/or location?
I also tried adding a LocationListener:
locationListener = new MyLocationListener();
locationsManager.RequestLocationUpdates(LocationManager.GpsProvider, 120000, 0, locationListener);
But the problem I had here was to create the MyLocationListener class. I implemented the four public methods (OnLocationChanged(Location) and so on), but Visual Studio complained about a missing Android.Runtime.IJavaObject method - does anyone have a simple example of a class that implements ILocationListener?
Thanks for any help. Martin
I got a kindly link to a sample at
https://github.com/gshackles/Sample-Projects/blob/master/MonoDroid/MonoDroidSamples/MonoDroidSamples/DemoActivities/LocationDemo/LocationActivity.cs
Which works fine on my Nexus S but still will not work on the emulator - so (perhaps) the issue is not a code issue.
I liked the technique in this sample of getting the "Activity" to implement ILocationListener as well as Activity - a neat solution to getting data back out of the "listener" function which had been giving me headaches when it was wrapped into another class.
I downloaded the bundle of samples and if you do the same then you will need to grab an mp3 file - rename it volbeat.mp3 and add it to the "raw" folder within "Resources" as it is missing.
partial answer as I am working on the same problem.
Your listener class that implements ILocationListener needs to be declared like
public class myLocationListener : Java.Lang.Object, ILOcationListener
{
//plus the public functions you identified
}
My attempt looks like this:
Android.Locations.Location iAmHere;
LocationManager myLoc = (LocationManager)GetSystemservice(Context.LocationService);
iAmHere = myLoc.GetLastKnownLocation(Android.Content.Context.LocationService);
but iAmHere is null on the emulator even when I have used TelNet to push a geo fix location through
Related
I'm developing an app using Xamarin's HCE feature.
The project structure is as follows.
hceSample
hceSample.Android
hceSample.iOS
I am implementing hce simulation code called hceService in hceSample, not hceSample.Android.
A function called Enable_Card exists in the hce service, and you want to use the NfcFCardEmulation.EnableService function in that function.
Activity and ComponentName are requested as parameters of the function.
The ComponentName area was handled easily, but I don't know how to get the Activity. Please advise.
This is the contents of enable_Card function of hceService.
private Activity activity = null;
private bool enable_Card(cardModel card)
{
try
{
sid = card.cardSN;
tag = "Felica";
emulation.EnableService(, componentName); //<- How to get Activity??
emulation.SetNfcid2ForService(componentName, sid);
return true;
}
catch
{
return false;
}
}
This is my first time asking a question on Stackoverflow.
I would appreciate it if you could point out any missing or incorrect parts.
I trying this
activity = Xamarin.Essentials.Platform.CurrentActivity; //<- this function is not found!
Added missing information!
The namespace of the Enable_Card function is located in hceSample.Service.
Are you using the NfcFCardEmulation.EnableService(Activity, ComponentName) Method, right?
The method is an android api from android sdk,you cannot use it directly in xamarin.form(yours is hceSample) project.
If you want to call the function in xamarin form project(hceSample) from native platform(hceSample.Android, or hceSample.iOS),you can use Xamarin.Forms DependencyService to achieve this.
The DependencyService class is a service locator that enables Xamarin.Forms applications to invoke native platform functionality from shared code.
For more information about DependencyService, you can check document Xamarin.Forms DependencyService. And there is a sample included in above document,which is helpful for you to understand DependencyService.
Note:
We recognize that hardware service is the right and ideal way to
implement in each OS project. However, I'm curious if there is a way
to code Android and iOS at the same time
Since the api you used is from android sdk, you can call it in native android or use DependencyService to call it on xamarin.form(yours is hceSample) project.
If you call it on xamarin.form(yours is hceSample) project, you also need to find the the corresponding function or interface in iOS.
I've been tasked with maintaining a Xamarin native project using MvvmCross 5.6.2. Not knowing exactly how to approach this, I've decided to update to one major version at a time (6 first, then 7 and 8). I'm not sure why I specifically have chosen 6.4.2, but it was maybe because this was the latest version of the majority of the plugins I was using on Nuget.
So far, the update has been a success and I have been able to fix all build errors. However, when running the application, I've been getting a null reference exception which I can't fully trace.
Based on the limited application output, I've been able to determine that the problem lies somewhere in my Android's setup.cs class (I think). I've been following Nick's .NET Travels advice on MvvmCross debugging. From viewing the MvvmCross 6.4.2. source and pasting in the following code in my own overrides:
public virtual void LoadPlugins(IMvxPluginManager pluginManager)
{
Type pluginAttribute = typeof(MvxPluginAttribute);
IEnumerable<Assembly> pluginAssemblies = GetPluginAssemblies();
foreach (Assembly item in pluginAssemblies)
{
IEnumerable<Type> enumerable = item.ExceptionSafeGetTypes();
foreach (Type item2 in enumerable)
{
if (TypeContainsPluginAttribute(item2))
{
pluginManager.EnsurePluginLoaded(item2);
}
}
}
bool TypeContainsPluginAttribute(Type type)
{
object[] customAttributes = type.GetCustomAttributes(pluginAttribute, inherit: false);
return ((customAttributes != null && customAttributes.Length != 0) ? 1 : 0) > (false ? 1 : 0);
}
}
public virtual IEnumerable<Assembly> GetPluginAssemblies()
{
string mvvmCrossAssemblyName = typeof(MvxPluginAttribute).Assembly.GetName().Name;
Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();
var test = from asmb in assemblies.AsParallel()
where AssemblyReferencesMvvmCross(asmb, mvvmCrossAssemblyName)
select asmb;
return test;
}
I'm able to see that GetPluginAssemblies doesn't return any enumerable, and the LoadPlugins method then produces the NullReferenceException. But I can't see what this NullReference actually is.
I followed the upgrading from 5 to 6 guide https://www.mvvmcross.com/documentation/upgrading/upgrade-to-mvvmcross-60.
I looked at the MvvmCross 6 and 6.4.0 release pages:
https://www.mvvmcross.com/mvvmcross-6.0.0-release/
https://www.mvvmcross.com/mvvmcross-6.4.0-release/
And I followed Benjamin Mayrargue's guide: https://medium.com/#bigoudi/upgrading-from-mvvmcross-5-to-mvvmcross-6-7ded83ecb69d
But I have been unable to load my plugins (previously they were bootstraps, but most of the guides say these can be discarded now and that loading plugins is easier).
I also attempted the answer suggested in this question How to use an mvvmcross plugin such as the file plugin.
But to no avail.
So I am asking if anyone knows a good guide or how to use plugins in MvvmCross 6.4.2.
Thank you.
Plugins are just a way to register things in the IoC Container. This is done by MvvmCross during startup using the LoadPlugins method in your Setup file.
Most of the time it should just work. However, there are some caveats.
If the Linker has gone ahead and linked away some of the plugins code, you will have a bad time. What you can do about that is to hint the mono linker to not strip the code away.
Add a LinkerPleaseInclude class and add a Include method in it that looks something like:
new MvvmCross.Plugin.Color.Platforms.Ios.Plugin().Load();
You can do that for every plugin you may want to use.
If LoadPlugins doesn't find the entry Assembly, sometimes it also does not register the plugins. You can override LoadPlugins in your Setup class and just call EnsurePluginLoaded:
public override void LoadPlugins(IMvxPluginManager pluginManager)
{
base.LoadPlugins(pluginManager);
pluginManager.EnsurePluginLoaded<MvvmCross.Plugin.Color.Platforms.Ios.Plugin>();
}
I want to thank Cheesebaron for his plugin support. I think I've fixed my issue and as it turned out, I don't think there is a plugin issue after all (yet).
Thanks to Toolmakersteve also. His suggestion for using a try catch in the OnCreate of my overridden MvxSplashScreenAppCompatActivity surfaced an issue with setting a theme for this activity. In actuality, this class was initially a MvxSplashScreenActivity.
Reverting this line, I then started getting NullReferenceExceptions on specific lines, all relating to IoC and lazy construction of singletons. The class Mvx seemed to be throwing up this error. On a sort of hunch from previous experience with my updating, I removed the MvvmCross.Platform using statement and checked what suggestions Mvx had available to it. It suggested MvvmCross and MvvmCross.Platform, so I tried the former instead. Sure enough, this moved my execution further, throwing up more Null Reference Exceptions. I also encountered one instance of failing to resolve IMvxResourceLoader from MvvmCross.Platform.Platform. Switching that to MvvmCross.Base did the trick.
This was only a chance fix through a bit of guess work. #CheeseBaron, should I add this as a note to this bit of documentation https://www.mvvmcross.com/documentation/upgrading/upgrade-to-mvvmcross-60? As mentioned, I'm as far as 6.4.2 now, so I'm not certain this is the right place for it.
I've got a few bugs with embedded resources to fix now, but if I encounter any more that are relevant to my question, I'll list them here.
I found an issue with localization in WinPhone app. I added couple of resources and implemented localization. It is working fine in simulator, but crashing on Phone with exception Exception thrown: 'System.Resources.MissingManifestResourceException' in mscorlib.ni.dll
Any help?
Thanks to a bit of googling and a helpful blog post I have managed to solve this issue that happened intermittently with Xamarin.Forms projects.
This is the blog post that led me to the solution:
http://blog.tpcware.com/2016/06/xamarin-forms-localization/
Basically, the way you access resources on Android and iOS with Xamarin.Forms and Windows Phone is different:
To make it short, we need to “automagically” use the ResourceLoader.GetString(…) method when running on Store apps, while continuing to use the regular ResourceManager.GetString(…) method on all other platform. And because in the Xamarin Forms solution we use a resource file of type RESX, we also have the automatically generated resource class.
The super clever idea contained in the above linked post is to “hack” the resource class injecting a derived class of ResourceManager with an overridden GetString(…) method into the resource class “resourceMan” property (for a more detailed explanation of this hack, you can read the post).
We need to create our own version of ResourceManager like so and swap it for the existing ResourceManager using reflection:
public class WinRTResourceManager : ResourceManager
{
readonly ResourceLoader _resourceLoader;
private WinRTResourceManager(string baseName, Assembly assembly) : base(baseName, assembly)
{
_resourceLoader = ResourceLoader.GetForViewIndependentUse(baseName);
}
public static void InjectIntoResxGeneratedApplicationResourcesClass(Type resxGeneratedApplicationResourcesClass)
{
resxGeneratedApplicationResourcesClass
.GetRuntimeFields()
.First(m => m.Name == "resourceMan")
.SetValue(null, new WinRTResourceManager(
resxGeneratedApplicationResourcesClass.FullName,
resxGeneratedApplicationResourcesClass.GetTypeInfo().Assembly));
}
public override string GetString(string name, CultureInfo culture)
{
return _resourceLoader.GetString(name);
}
}
All that's then left to do is call this when the app starts for the first time:
WinRTResourceManager.InjectIntoResxGeneratedApplicationResourcesClass(typeof(AppResources));
After making these changes everything should work fine now.
Of course this is absolutely a hack but I have notified the Xamarin.Forms team of the issue and they are looking into it so hopefully it will be solved soon!
I am trying to implement a custom membership provider in Sitefinity, and have followed through the documentation at: http://docs.sitefinity.com/tutorial-create-a-custom-membership-provider
When I come to register the provider in the Sitefinity backend, I get the message The following required properties are not set: type
I have checked, double checked and checked again the namespace and class names, and can even declare a variable as the provider type in the code-behind, yet it just won't have it.
My provider is defined thus:
namespace SitefinityWebApp
{
public class WebsiteMembersProvider : MembershipDataProvider
{
public WebsiteMembersProvider()
{
//... etc
I am registering the provider in the SF backend as:
SitefinityWebApp.WebsiteMembersProvider, SitefinityWebApp
And I can go into the code behind on one of my master pages and code:
SitefinityWebApp.WebsiteMembersProvider MyTestProvider;
and indeed, the class appears in the intellisense offerings just fine.
and the project all compiles/runs fine - but SF won't let me use the custom provider! I have also tried adding the provider manually in the securityconfig.config file - similar result.
Any idea anyone?
I went through the tutorial to try it myself and ran into the same problem as you.
Are you sure that you're putting this
SitefinityWebApp.WebsiteMembersProvider, SitefinityWebApp
in the ProviderType field (and not the 'Global resource class ID' field, which is what I initially did)? It seems like that error message shows up if I remove the text from that field and attempt to save (and also when it can't resolve that type).
Otherwise, I'm not sure what else it could be, aside from maybe recycling the app pool.
I am trying to create a Xamarin Java Binding to the Spotify Android SDK. The SDK is now separated into two parts, one for authentication and one for the player. The former java binding works, however, the seconds gives me an error.
The original question was asked on the Xamarin Forums.
Hi,
I am trying to create a binding project for the Spotify Android SDK.
The SDK is seperated into two .aar files. One for authentication and one for media playback (Player).
Firstly I tried having both .aar files in one Binding Project, but the Player.aar was ignored. However, moving it to its own seem to work.
Now, my issue is related to the Java Interface NativePlayerNotificationCallback which is generated to IPlayerNotificationCallback (hence the lack og Notification), but in the Player class it tried to implement: global::Com.Spotify.Android.Player.INativePlayerNotificationCallback.
I can find no other mention of INativePlayerNotificationCallback in the decompiled files. Only IPlayerNotificationCallback.
I understand that this is a bit difficult to imagine. Here are the java class files seen in JD-GUI:
The generated files are listed here:
Inside the file Com.Spotify.Sdk.Android.Player.IPlayerNotificationCallback.cs:
And the error message itself
Error CS0234: The type or namespace name INativePlayerNotificationCallback' does not exist in the namespaceCom.Spotify.Sdk.Android.Player'. Are you missing an assembly reference?
I would really appreciate any insight as to how I can get this to work. It looks to me like there are some inconsistencies in the naming of the interface, but I am not sure.
Thank you for helping out,
Fredrik
Should be fixed by adding metadata to Player binding project:
<metadata>
<attr path="/api/package[#name='com.spotify.sdk.android.player']/interface[#name='NativePlayerNotificationCallback']" name="visibility">public</attr>
</metadata>
and Player class extension (into the Additions directory):
using System.Collections;
using Java.Lang;
using Java.Util.Concurrent;
namespace Com.Spotify.Sdk.Android.Player
{
public partial class Player
{
public IList InvokeAll(ICollection tasks)
{
return null;
}
public IList InvokeAll(ICollection tasks, long timeout, TimeUnit unit)
{
return null;
}
public Object InvokeAny(ICollection tasks)
{
return null;
}
public Object InvokeAny(ICollection tasks, long timeout, TimeUnit unit)
{
return null;
}
}
}
You will probably need to implement these methods correctly by calling generic methods.
Also I had to add metadata to Auth library binding project (I found it in your old topics) and referenced Auth project from Player project as it uses some of the classes (maybe that's no necessary).