Develop Reference

How to Retrieve data inside of the generated key that I just push

I'm trying to retrieve the data inside of the generated key from firebase real time database using C# language and the retrieve data will show in RecyclerViewer. I try everything but still not showing in RecyclerView.
This is my code
how to solve this?
THIS IS THE LISTENER:
using AdamsonsEDApp.Data_Models;
using AdamsonsEDApp.Helpers;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Firebase.Database;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using static AdamsonsEDApp.Listeners.StaffListeners;
namespace AdamsonsEDApp.Listeners
{
public class PackageInfoListeners : Java.Lang.Object, IValueEventListener
{
List<PackageInfo> packageinfoList = new List<PackageInfo>();
public event EventHandler<PackageInfoDataEventArgs> PackageInfoRetrieved;
public class PackageInfoDataEventArgs : EventArgs
{
public List<PackageInfo> PackageInfo { get; set; }
}
public void OnCancelled(DatabaseError error)
{
throw new NotImplementedException();
}
public void OnDataChange(DataSnapshot snapshot)
{
if (snapshot.Value != null)
{
var child = snapshot.Children.ToEnumerable<DataSnapshot>();
packageinfoList.Clear();
foreach (DataSnapshot infoData in child)
{
PackageInfo info = new PackageInfo();
info.packageinfoID = infoData.Key;
info.packageinfoName = infoData.Child("infoName").Value.ToString();
info.packageinfoQty = infoData.Child("infoQty").Value.ToString();
packageinfoList.Add(info);
}
PackageInfoRetrieved.Invoke(this, new PackageInfoDataEventArgs { PackageInfo = packageinfoList });
}
}
public void Create()
{
DatabaseReference infoRef = AppDataHelper.GetDatabase().GetReference("packageinfo");
infoRef.AddValueEventListener(this);
}
}
}
This is the Activit
using AdamsonsEDApp.Adapters;
using AdamsonsEDApp.Data_Models;
using AdamsonsEDApp.Fragments;
using AdamsonsEDApp.Listeners;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Support.V7.App;
using Android.Support.V7.Widget;
using Android.Views;
using Android.Widget;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace AdamsonsEDApp.Resources.activities
{
[Activity(Label = "#string/app_name", Theme = "#style/AppTheme", MainLauncher = false)]
public class eventpackageinfo_activity : AppCompatActivity
{
string packageinfoname, packageinfoqty;
TextView infonameText, infoqtyText;
ImageView /*removeButton,*/ backpackageButton/*, searchButton*/;
//EditText searchText;
RecyclerView packageinfoRecyclerView;
Button addinclusionsButton;
AddPackageInfoFragment addpackageinfoFragment;
PackageInfoAdapter packageinfoadapter;
List<PackageInfo> packageinfoList;
PackageInfoListeners infoListeners;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
SetContentView(Resource.Layout.eventpackageinfos);
infonameText = (TextView)FindViewById(Resource.Id.infonameText);
infoqtyText = (TextView)FindViewById(Resource.Id.infoqtyText);
addinclusionsButton = (Button)FindViewById(Resource.Id.addinclusionsButton);
backpackageButton = (ImageView)FindViewById(Resource.Id.backpackageButton);
packageinfoRecyclerView = (RecyclerView)FindViewById(Resource.Id.packageinfoRecyclerView);
backpackageButton.Click += BackpackageButton_Click;
addinclusionsButton.Click += AddinclusionsButton_Click;
RetrieveData();
}
private void AddinclusionsButton_Click(object sender, EventArgs e)
{
}
private void BackpackageButton_Click(object sender, EventArgs e)
{
Intent infointent = new Intent(this, typeof(eventpackage_activity));
StartActivity(infointent);
}
private void SetupPackageInfoRecyclerView()
{
packageinfoRecyclerView.SetLayoutManager(new Android.Support.V7.Widget.LinearLayoutManager(packageinfoRecyclerView.Context));
PackageInfoAdapter packageinfoadapter = new PackageInfoAdapter(packageinfoList);
packageinfoRecyclerView.SetAdapter(packageinfoadapter);
}
public void RetrieveData()
{
infoListeners = new PackageInfoListeners();
infoListeners.Create();
infoListeners.PackageInfoRetrieved += InfoListeners_PackageInfoRetrieved;
}
private void InfoListeners_PackageInfoRetrieved(object sender, PackageInfoListeners.PackageInfoDataEventArgs e)
{
packageinfoList = e.PackageInfo;
SetupPackageInfoRecyclerView();
}
}
}

Are you sure you're listening to the correct path in the database? Your code attaches a listener to:
DatabaseReference infoRef = AppDataHelper.GetDatabase().GetReference("packageinfo");
But your screenshot shows a node named eventpackage under the root.

How to make the screen go dark when a proximity sensor is detected on Android?

I have an application for calls, when the user enters the call page, there is a voice, etc., I want to implement a proximity sensor, so that when the user brings the phone to his ear, the screen is inactive and darkened. Here is my code for the sensor (it works).
using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.Hardware;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Corporate_messenger.DB;
using Corporate_messenger.Service;
using Corporate_messenger.Service.Notification;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Xamarin.Forms;
namespace Corporate_messenger.Droid
{
[Activity(Label = "CallActivity",ScreenOrientation = ScreenOrientation.Portrait)]
public class CallActivity : Activity, ISensorEventListener
{
Android.Widget.Button BtnStartCall;
Android.Widget.Button BtnEndCall;
Android.Widget.Button BtnEndCallCenter;
SensorManager sensorManager;
Sensor proximitySensor;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
sensorManager = (SensorManager) GetSystemService(Context.SensorService);
sensorManager.RegisterListener(this, sensorManager.GetDefaultSensor(SensorType.Proximity), SensorDelay.Ui);
proximitySensor = sensorManager.GetDefaultSensor(SensorType.Proximity);
}
public void OnAccuracyChanged(Sensor sensor, [GeneratedEnum] SensorStatus accuracy)
{
var s = sensor;
}
public void OnSensorChanged(SensorEvent e)
{
// The sensor is triggered here, at this moment I can’t figure out how to Hide the screen (do not
// active , darken)
}
}
}
Please help me to make the screen not active "Dimed"

getting 'MediationRewardedVideoAdListenerImplementor is not abstract and does not override abstract method' when trying to use admob in xamarin forms

MediationRewardedVideoAdListenerImplementor is not abstract and does not override abstract method zzc(Bundle) in MediationRewardedVideoAdListener
public class MediationRewardedVideoAdListenerImplementor SocialFeedTest.Android C:\Users\blain\source\repos\SocialFeedTest\SocialFeedTest\SocialFeedTest.Android\obj\Debug\90\android\src\mono\com\google\android\gms\ads\reward\mediation\MediationRewardedVideoAdListenerImplementor.java 4
following this tutorial here https://xamarinhelp.com/admob-xamarin-forms-display-google-ads-mobile-app/ . this is hard to diagnose for me because it doesn't break on a line number in my code it says the error is in auto generated code i do not understand. neither does it say there is a error in my code but it will not let me build it or emulate it.
heres my code
xamarin.forms
using System;
using System.Collections.Generic;
using System.Text;
using Xamarin.Forms;
namespace SocialFeedTest.Control
{
public class AdMobView : View
{
public static readonly BindableProperty AdUnitIdProperty = BindableProperty.Create(
nameof(AdUnitId),
typeof(string),
typeof(AdMobView),
string.Empty);
public string AdUnitId
{
get => (string)GetValue(AdUnitIdProperty);
set => SetValue(AdUnitIdProperty, value);
}
}
}
android
renderer
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.Gms.Ads;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using SocialFeedTest.Control;
using SocialFeedTest.Droid;
using Xamarin.Forms;
using Xamarin.Forms.Platform.Android;
[assembly: ExportRenderer(typeof(AdMobView), typeof(AdMobViewRenderer))]
namespace SocialFeedTest.Droid
{
public class AdMobViewRenderer : ViewRenderer<AdMobView, AdView>
{
public AdMobViewRenderer(Context context) : base(context) { }
protected override void OnElementChanged(ElementChangedEventArgs<AdMobView> e)
{
base.OnElementChanged(e);
if (e.NewElement != null && Control == null)
SetNativeControl(CreateAdView());
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == nameof(AdView.AdUnitId))
Control.AdUnitId = Element.AdUnitId;
}
private AdView CreateAdView()
{
var adView = new AdView(Context)
{
AdSize = AdSize.SmartBanner,
AdUnitId = Element.AdUnitId
};
adView.LayoutParameters = new LinearLayout.LayoutParams(LayoutParams.MatchParent, LayoutParams.MatchParent);
adView.LoadAd(new AdRequest.Builder().Build());
return adView;
}
}
}
main activity
using System;
using Android.App;
using Android.Content.PM;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
namespace SocialFeedTest.Droid
{
[Activity(Label = "SocialFeedTest", Icon = "#mipmap/icon", Theme = "#style/MainTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
{
protected override void OnCreate(Bundle savedInstanceState)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(savedInstanceState);
Android.Gms.Ads.MobileAds.Initialize(ApplicationContext, "ca-app-pub-5184019642309342~9928782520");
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
LoadApplication(new App());
}
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
{
Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);
base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
}
ios
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Text;
using Foundation;
using Google.MobileAds;
using SocialFeedTest.Control;
using SocialFeedTest.iOS;
using UIKit;
using Xamarin.Forms;
using Xamarin.Forms.Platform.iOS;
[assembly: ExportRenderer(typeof(AdMobView), typeof(AdMobViewRenderer))]
namespace SocialFeedTest.iOS
{
public class AdMobViewRenderer : ViewRenderer<AdMobView, BannerView>
{
protected override void OnElementChanged(ElementChangedEventArgs<AdMobView> e)
{
base.OnElementChanged(e);
if (Control == null)
{
SetNativeControl(CreateBannerView());
}
}
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e)
{
base.OnElementPropertyChanged(sender, e);
if (e.PropertyName == nameof(BannerView.AdUnitId))
Control.AdUnitId = Element.AdUnitId;
}
private BannerView CreateBannerView()
{
var bannerView = new BannerView(AdSizeCons.SmartBannerPortrait)
{
AdUnitId = Element.AdUnitId,
RootViewController = GetVisibleViewController()
};
bannerView.LoadRequest(GetRequest());
Request GetRequest()
{
var request = Request.GetDefaultRequest();
return request;
}
return bannerView;
}
private UIViewController GetVisibleViewController()
{
var windows = UIApplication.SharedApplication.Windows;
foreach (var window in windows)
{
if (window.RootViewController != null)
{
return window.RootViewController;
}
}
return null;
}
}
}
main
using System;
using System.Collections.Generic;
using System.Linq;
using Foundation;
using UIKit;
namespace SocialFeedTest.iOS
{
public class Application
{
// This is the main entry point of the application.
static void Main(string[] args)
{
// if you want to use a different Application Delegate class from "AppDelegate"
// you can specify it here.
UIApplication.Main(args, null, "AppDelegate");
}
}
}

If you are using that version there are going to be compile warnings because it is not updated for the SDK change in ads from google.
Your manifest now should have this.
meta-data android:name="com.google.android.gms.ads.APPLICATION_ID" android:value="ca-app-pub-xxxxxxxxx-xxxxxxxxxx"
I suggest to use the Xamarin.GooglePlayServices.Ads.Lite if you only want ads.
You can see this link for how to do it.

Toast message in new item, using visual studio (Xamarin)

I made a simple program, which include TextView and Button; and every time the Button is clicked, the counter on TextView grows by 1.
I also wanted that every time I click the Button, toast message will be seen.
I opened a new item in Visual Studio to do it :
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.Support.V7.App;
namespace perek1_helek1_dug1_listening
{
class Game_code : Button, Android.Views.View.IOnClickListener
{
private int point = 0;
private TextView screen;
public Game_code( TextView screen, Context context):base(context)
{
this.screen = screen;
}
public static void ShowToastMethod(Context context)
{
Toast.MakeText(context, "mymessage ", ToastLength.Long).Show();
}
public void OnClick(View v)
{
if (v.Id == Resource.Id.btnxml)
{
point++;
**ShowToastMethod( context);**
}
screen.Text = "" + point;
}
}
}
That is How MainActivity.cs looks like:
using Android.App;
using Android.OS;
using Android.Support.V7.App;
using Android.Runtime;
using Android.Widget;
namespace perek1_helek1_dug1_listening
{
[Activity(Label = "#string/app_name", Theme = "#style/AppTheme", MainLauncher = true)]
public class MainActivity : AppCompatActivity
{
TextView tv;
Button btn;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.activity_main);
tv = (TextView)FindViewById(Resource.Id.textboxml);
btn = (Button)FindViewById(Resource.Id.btnxml);
Game_code game = new Game_code(tv, this);
btn.SetOnClickListener(game);
}
}
}
However, the line :
ShowToastMethod( context);
makes the error. What should I do?

I would suggest you use the events that C# has provided:
int point=0;
.
.
.
//after you find button view by ID
btn.Click+= delegate {
tv.Text=point++;
ShowToastMethod();
};
public void ShowToastMethod()
{
Toast.MakeText(this, "mymessage ", ToastLength.Long).Show();
}

I googled around and found that all I had to do is change the line :
ShowToastMethod( context);
to:
ShowToastMethod(this.Context );
Thank you anyway.

c# xamarin - Android background service closing when I close application

My Android service closing when I close the main activity.
I tried add to the AndroidManifest.xml: <service android:name="App7.SimpleService" android:stopWithTask="false">
I also tried the following code for starting service:
Intent intent2 = new Intent(ApplicationContext, typeof(SimpleService));
StartService(intent2);
and
StartService(new Intent("App7.SimpleService"));
I tried also the return START_STICKY; and return StartCommandResult.Sticky;, but no effects.
My code:
SimpleService.cs:
using System;
using System.Threading;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Util;
using System.Net;
using System.IO;
using System.Xml;
using System.Xml.Linq;
using Android.Widget;
using Android;
using App7;
using static System.Net.Mime.MediaTypeNames;
using System.Threading.Tasks;
using System.Text;
namespace SimpleService
{
[Service]
[IntentFilter(new String[] { "App7.SimpleService" })]
public class SimpleServiceBinder : Service
{
public static StartCommandResult START_STICKY { get; private set; }
public override StartCommandResult OnStartCommand(Intent intent, StartCommandFlags flags, int startId)
{
/// My service code
return StartCommandResult.Sticky;
}
public override IBinder OnBind(Intent intent)
{
// binder = new SimpleService(this);
return null;
}
public override void OnDestroy()
{
base.OnDestroy();
}
}
}
MainActivity.cs:
using System;
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using App7;
using System.Net;
using System.IO;
using System.Collections.Specialized;
using Android.Webkit;
using System.Threading.Tasks;
namespace SimpleService
{
[Activity(Label = "aplikacja1", MainLauncher = true)]
[Service]
public class MainActivity : Activity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.Main);
//////////////////////////////////////
this.StartService(new Intent(this, typeof(SimpleServiceBinder)));
/// I tried also////
// Intent intent2 = new Intent(ApplicationContext, typeof(SimpleService));
// StartService(intent2);
// StartService(new Intent("App7.SimpleService"));
}
}
}
Please, help me