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How to output sms on textview on sms Recieve?

I've made this simple app for recieving sms,When I receive a message I want to output this on my TextView,upuntil now for testing I was just doing
that inside a button .You recieve a message ,click on the button and you get the sms on textview.If I try to do this without a button ,at the start of compilation
I get a null reference exception.Can anyone help me on this ?
//----------MainActivity.cs---------------
using Android.App;
using Android.OS;
using Android.Support.V7.App;
using Android.Runtime;
using Android.Widget;
using Android.Content;
using Android.Telephony;
using Android.Provider;
using Android.Util;
using Java.Lang;
using System.Text.RegularExpressions;
using Xamarin.Essentials;
using System;
using Android;
using Android.Support.V4.Content;
using Android.Content.PM;
namespace Sms_Receiver2
{
[Activity(Label = "#string/app_name", Theme = "#style/AppTheme", MainLauncher = true)]
public class MainActivity : AppCompatActivity
{
public Receiver1 _receiver; // Receiver class
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.activity_main);
TextView translatedPhoneWord = FindViewById<TextView>(Resource.Id.TranslatedPhoneword);
Button translateButton = FindViewById<Button>(Resource.Id.TranslateButton);
if (ContextCompat.CheckSelfPermission(this, Manifest.Permission.ReadSms) != (int)Permission.Granted)
{
RequestPermissions(new string[] { Manifest.Permission.ReadSms, Manifest.Permission.SendSms, Manifest.Permission.ReceiveSms }, 0);
}
translateButton.Click += (s, e) =>
{};
translatedPhoneWord.Text = _receiver.message;// null reference exception
}
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);
}
protected override void OnResume()
{
base.OnResume();
_receiver = new Receiver1();
IntentFilter filter = new IntentFilter();
filter.AddAction("android.provider.Telephony.SMS_RECEIVED");
filter.AddAction("android.provider.Telephony.SMS_DELIVER");
RegisterReceiver(_receiver, filter);
}
protected override void OnPause()
{
base.OnPause();
UnregisterReceiver(_receiver);
}
}
}
//---------Reciever.cs -------------
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Android.Telephony;
using Android.Provider;
namespace Sms_Receiver2
{
[BroadcastReceiver(Enabled = true, Exported = true, Permission = "android.permission.BROADCAST_SMS")]
[IntentFilter(new[] { "android.provider.Telephony.SMS_RECEIVED", "android.provider.Telephony.SMS_DELIVER" }, Priority = (int)IntentFilterPriority.HighPriority)]
public class Receiver1 : BroadcastReceiver
{
public string message, address = "";
public static readonly string INTENT_ACTION = "android.provider.Telephony.SMS_RECEIVED";
public override void OnReceive(Context context, Intent intent)
{
if (intent.HasExtra("pdus"))
{
var smsArray = (Java.Lang.Object[])intent.Extras.Get("pdus");
foreach (var item in smsArray)
{
var sms = SmsMessage.CreateFromPdu((byte[])item);
address = sms.OriginatingAddress;
message = sms.MessageBody;
Toast.MakeText(context, "Number :" + address + "Message : " + message, ToastLength.Short).Show();
}
}
}
}
}

Slight modification of your code works
[Activity(Label = "#string/app_name", Theme = "#style/AppTheme.NoActionBar", MainLauncher = true)]
public class MainActivity : AppCompatActivity
{
private SMSBroadcastReceiver _receiver;
private TextView _smsTextView; //Textview where list of received sms will show
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
SetContentView(Resource.Layout.activity_main);
_smsTextView = FindViewById<TextView>(Resource.Id.smstextview);
_receiver = new SMSBroadcastReceiver();
_receiver.SmsActionDelegate = InokeOnNewSMS;
IntentFilter filter = new IntentFilter();
filter.AddAction("android.provider.Telephony.SMS_RECEIVED");
filter.AddAction("android.provider.Telephony.SMS_DELIVER");
RegisterReceiver(_receiver, filter);
}
//this method will be invoked when new sms is received in the broadcast received
public void InokeOnNewSMS(string address, string message)
{
_smsTextView.Text += $"{address} : {message}\n\n";
}
}
[BroadcastReceiver(Enabled = true, Exported = true, Permission = "android.permission.BROADCAST_SMS")]
[IntentFilter(new[] { "android.provider.Telephony.SMS_RECEIVED", "android.provider.Telephony.SMS_DELIVER" }, Priority = (int)IntentFilterPriority.HighPriority)]
public class SMSBroadcastReceiver : BroadcastReceiver
{
public string message = "", address = "";
public static readonly string INTENT_ACTION = "android.provider.Telephony.SMS_RECEIVED";
public Action<string, string> SmsActionDelegate;
public override void OnReceive(Context context, Intent intent)
{
if (intent.HasExtra("pdus"))
{
var smsArray = (Java.Lang.Object[])intent.Extras.Get("pdus");
foreach (var item in smsArray)
{
var sms = SmsMessage.CreateFromPdu((byte[])item);
address = sms.OriginatingAddress;
message = sms.MessageBody;
SmsActionDelegate?.Invoke(address, message);
Toast.MakeText(context, "Number :" + address + "Message : " + message, ToastLength.Short).Show();
}
}
}
}

foreground service never stop xamarin android

i have xamarin android application that read from clipboard and write to it. it uses foreground services if the user hit the button. the problem is when the user hit the button again the services disappear from running services but still doing it's job (editing copied text). how can i completely stop it from working?
foreground.cs:
public override IBinder OnBind(Intent intent)
{
return null;
}
public override StartCommandResult OnStartCommand(Intent intent, StartCommandFlags flags, int startId)
{
Clipboard.ClipboardContentChanged += async (o, e) =>
{
var text = await Clipboard.GetTextAsync();
Toast.MakeText(this, text, ToastLength.Long).Show();
if (text.Contains("#"))
{
await Clipboard.SetTextAsync(text.Replace("#", ""));
}
};
Notification notif = ReturnNotif();
StartForeground(1, notif);
return StartCommandResult.NotSticky;
}
public override void OnDestroy()
{
base.OnDestroy();
}
public override void OnCreate()
{
base.OnCreate();
}
public override bool StopService(Intent name)
{
StopForeground(true);
StopSelf();
return base.StopService(name);
}
MainActivity.cs:
if (id == Resource.Id.myService)
{
if (count != 1)
{
count = 1;
var intent = new Intent(this, typeof(foreground));
intent.SetAction("No");
if (Build.VERSION.SdkInt >= BuildVersionCodes.O)
{
StartForegroundService(intent);
}
else
{
StartService(intent);
}
}
else
{
var intent = new Intent(this,typeof(foreground));
StopService(intent);
Toast.MakeText(this, "Service Stopped", ToastLength.Long).Show();
count = 0;
}
}
what i am doing wrong ?
Edit :
Service will completely stops if the app is removed from recently used apps.

In your MyForegroundService.cs. Just add StopForeground(true) in OnDestroy() method like following code.
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;
namespace ForegroundServiceDemo
{
[Service]
class MyForegroundService : Service
{
public const int SERVICE_RUNNING_NOTIFICATION_ID = 10000;
[return: GeneratedEnum]
public override StartCommandResult OnStartCommand(Intent intent, [GeneratedEnum] StartCommandFlags flags, int startId)
{
CreateNotificationChannel();
string messageBody = "service starting";
// / Create an Intent for the activity you want to start
Intent resultIntent = new Intent(this,typeof(Activity1));
// Create the TaskStackBuilder and add the intent, which inflates the back stack
TaskStackBuilder stackBuilder = TaskStackBuilder.Create(this);
stackBuilder.AddNextIntentWithParentStack(resultIntent);
// Get the PendingIntent containing the entire back stack
PendingIntent resultPendingIntent = stackBuilder.GetPendingIntent(0, PendingIntentFlags.UpdateCurrent);
var notification = new Notification.Builder(this, "10111")
.SetContentIntent(resultPendingIntent)
.SetContentTitle("Foreground")
.SetContentText(messageBody)
.SetSmallIcon(Resource.Drawable.main)
.SetOngoing(true)
.Build();
StartForeground(SERVICE_RUNNING_NOTIFICATION_ID, notification);
//do you work
return StartCommandResult.Sticky;
}
public override void OnDestroy()
{
base.OnDestroy();
StopForeground(true);
}
public override IBinder OnBind(Intent intent)
{
return null;
}
void CreateNotificationChannel()
{
if (Build.VERSION.SdkInt < BuildVersionCodes.O)
{
return;
}
var channelName = Resources.GetString(Resource.String.channel_name);
var channelDescription = GetString(Resource.String.channel_description);
var channel = new NotificationChannel("10111", channelName, NotificationImportance.Default)
{
Description = channelDescription
};
var notificationManager = (NotificationManager)GetSystemService(NotificationService);
notificationManager.CreateNotificationChannel(channel);
}
}
}
When you want to stop it. Just call following code.
Android.App.Application.Context.StopService(intent);
Here is my code in the Activity.
public class MainActivity : AppCompatActivity
{
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
Xamarin.Essentials.Platform.Init(this, savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.activity_main);
Button button1 = FindViewById<Button>(Resource.Id.button1);
Button button2 = FindViewById<Button>(Resource.Id.button2);
button2.Click += Button2_Click;
button1.Click += Button1_Click;
}
Intent intent;
private void Button2_Click(object sender, System.EventArgs e)
{
// stop foreground service.
Android.App.Application.Context.StopService(intent);
}
private void Button1_Click(object sender, System.EventArgs e)
{
intent = new Intent(Android.App.Application.Context, typeof(MyForegroundService));
// start foreground service.
if (Android.OS.Build.VERSION.SdkInt >= Android.OS.BuildVersionCodes.O)
{
StartForegroundService(intent);
}
}
Here is running GIF.
====Update====
the expected behavior is : when service stopped user can copy and paste normally without the service interference
You can use following way to achieve that.Use Clipboard.ClipboardContentChanged += Clipboard_ClipboardContentChanged; to execute the behavior, use Clipboard.ClipboardContentChanged -= Clipboard_ClipboardContentChanged; to disable the behavior in the OnDistory method.
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 Xamarin.Essentials;
namespace ForegroundServiceDemo
{
[Service]
class MyForegroundService : Service
{
public const int SERVICE_RUNNING_NOTIFICATION_ID = 10000;
[return: GeneratedEnum]
public override StartCommandResult OnStartCommand(Intent intent, [GeneratedEnum] StartCommandFlags flags, int startId)
{
CreateNotificationChannel();
string messageBody = "service starting";
Clipboard.ClipboardContentChanged += Clipboard_ClipboardContentChanged;
// / Create an Intent for the activity you want to start
Intent resultIntent = new Intent(this,typeof(Activity1));
// Create the TaskStackBuilder and add the intent, which inflates the back stack
TaskStackBuilder stackBuilder = TaskStackBuilder.Create(this);
stackBuilder.AddNextIntentWithParentStack(resultIntent);
// Get the PendingIntent containing the entire back stack
PendingIntent resultPendingIntent = stackBuilder.GetPendingIntent(0, PendingIntentFlags.UpdateCurrent);
var notification = new Notification.Builder(this, "10111")
.SetContentIntent(resultPendingIntent)
.SetContentTitle("Foreground")
.SetContentText(messageBody)
.SetSmallIcon(Resource.Drawable.main)
.SetOngoing(true)
.Build();
StartForeground(SERVICE_RUNNING_NOTIFICATION_ID, notification);
//do you work
return StartCommandResult.Sticky;
}
private async void Clipboard_ClipboardContentChanged(object sender, EventArgs e)
{
//throw new NotImplementedException();
var text = await Clipboard.GetTextAsync();
Toast.MakeText(this, text, ToastLength.Long).Show();
if (text.Contains("#"))
{
await Clipboard.SetTextAsync(text.Replace("#", ""));
}
}
public override void OnDestroy()
{
base.OnDestroy();
Clipboard.ClipboardContentChanged -= Clipboard_ClipboardContentChanged;
StopForeground(true);
}
public override IBinder OnBind(Intent intent)
{
return null;
}
void CreateNotificationChannel()
{
if (Build.VERSION.SdkInt < BuildVersionCodes.O)
{
return;
}
var channelName = Resources.GetString(Resource.String.channel_name);
var channelDescription = GetString(Resource.String.channel_description);
var channel = new NotificationChannel("10111", channelName, NotificationImportance.Default)
{
Description = channelDescription
};
var notificationManager = (NotificationManager)GetSystemService(NotificationService);
notificationManager.CreateNotificationChannel(channel);
}
}
}
Here is run GIF.

To prevent this issues, add a "myServiceIsRunning" bool value in the Properties dictionary when you start your foreground method like this:
Application.Current.Properties["myServiceIsRunning"] = true
With a get function or whatever you want, before start the foreground method, verify if the key "myServiceIsRunning" exist, and if it exist, how is his status:
public bool getRunningStateMyService(){
bool myServiceIsRunningValue;
if (Application.Current.Properties.ContainsKey("myServiceIsRunning"))
{
myServiceIsRunningValue = Convert.ToBoolean(Application.Current.Properties["myServiceIsRunning"]);
}
else
{
myServiceIsRunningValue = false;
}
return locationServiceIsRunning;
}
After you get the value, with a simple if{}/else{}, you can choose to start a new instance or not if you're service is running or not. Or, in you're case just prevent the foreground method continue to run.
Don't forget to set your value to false when you destroy the foreground method.
the Properties dictionary can store data trought closing app to. you can have more infos here:
https://learn.microsoft.com/fr-fr/xamarin/xamarin-forms/app-fundamentals/application-class#Properties_Dictionary

How to populate a Listview in xamarin android c# using REST API, custom listview, adapter, row layout

I have very limited know how of programming in general. Trying to create a custom list view to display an image and a message mainly.
Ive been trying to follow tutorials on how to do it and cannot for the life of me work out how to make it work ..
currently have these errors and have no idea how to fix:
[![msgInbox screen error][1]][1]
This is the msgInbox activity with the list:
using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Linq;
using System.Net;
using System.Text;
using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Dribl;
using Newtonsoft.Json;
namespace Dribl.Droid
{
[Activity(Label = "MsgInbox", Theme = "#style/CustomActionBarTheme")]
public class MsgInbox : Activity
{
TextView txt;
//Button backBtn;
private List<Message> msgItems;
private ListView msgListview;
//private BaseAdapter<msgInfo> mAdapter;
//action bar layout buttons
LinearLayout surveysBtn;
LinearLayout availabilityBtn;
LinearLayout inboxBtn;
LinearLayout dashboardBtn;
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.msgInbox);
//add the action bar to the layout
ActionBar.SetCustomView(Resource.Layout.action_bar);
ActionBar.SetDisplayShowCustomEnabled(true);
//actionbar layout btns
//actionbar layout btns
surveysBtn = FindViewById<LinearLayout>(Resource.Id.SurveyLayout);
surveysBtn.Click += surveyBtn_Click;
inboxBtn = FindViewById<LinearLayout>(Resource.Id.InboxLayout);
inboxBtn.Click += InboxBtn_Click;
availabilityBtn = FindViewById<LinearLayout>(Resource.Id.availabilityLayout);
availabilityBtn.Click += availabilityBtn_Click;
dashboardBtn = FindViewById<LinearLayout>(Resource.Id.dashboardLayout);
dashboardBtn.Click += dashboardBtn_Click;
txt = FindViewById<TextView>(Resource.Id.msg_txt);
WebClient client = new WebClient();
System.Uri uri = new System.Uri("http://dribl.com/api/getAllMyMessages");
NameValueCollection parameters = new NameValueCollection();
parameters.Add("token", GlobalVariables.token);
client.UploadValuesAsync(uri, parameters);
client.UploadValuesCompleted += client_UploadValuesCompleted;
//listview
msgListview = FindViewById<ListView>(Resource.Id.msgListView);
msgListview.ItemClick += MsgListview_ItemClick;
}
private void MsgListview_ItemClick(object sender, AdapterView.ItemClickEventArgs e)
{
Intent intent = new Intent(this, typeof(msgDetails));
//add in a variable to store the message that was clicked on and pass across to next pages txtfield
intent.PutExtra("msgDet", "This is a message");
StartActivity(intent);
}
protected internal void client_UploadValuesCompleted(object sender, UploadValuesCompletedEventArgs e)
{
string json = Encoding.UTF8.GetString(e.Result);
List<Message> messages = JsonConvert.DeserializeObject<List<Message>>(json);
//display the retrieved msg in the console output
//Console.WriteLine(message[1].message + " is the message");
//display the msg in a text view at top of page
//txt.Text = message[1].message;
//get the list view create a string to store and add to the list view based on the json return
// msgItems = new List<Message>();
// for (int c = 0; c < message.Count; c++)
// {
// msgItems.Add(message[c].message);
//msgItems.Add(new Message() { message = "pauls hectic"});
//}
msgItems = messages;
// msgAdapter msgAdapter = new msgAdapter(this, msgItems);
//msgListview.Adapter = msgAdapter;
//Msgs.Add(message[1].message);
//Msgs.Add(message[0].message);
// ArrayAdapter<Message> adapter = new ArrayAdapter<Message>(this, Android.Resource.Layout.SimpleListItem1, msgItems);
//msgListview.Adapter = adapter;
// msgAdapter msgAdapter = new MsgAdapter(this, message);
//var msgAdapter = new MsgAdapter(this, message);
MsgAdapter msgAdapter = new MsgAdapter(this, messages);
}
void surveyBtn_Click(object sender, EventArgs e)
{
Intent intent = new Intent(this, typeof(Surveys));
this.StartActivity(intent);
this.Finish();
}
void dashboardBtn_Click(object sender, EventArgs e)
{
Intent intent = new Intent(this, typeof(dashboard));
this.StartActivity(intent);
this.Finish();
}
void availabilityBtn_Click(object sender, EventArgs e)
{
Intent intent = new Intent(this, typeof(Availability));
this.StartActivity(intent);
this.Finish();
}
void InboxBtn_Click(object sender, EventArgs e)
{
Intent intent = new Intent(this, typeof(MsgInbox));
this.StartActivity(intent);
this.Finish();
}
}
}
This is the msgInfo class:
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;
namespace Dribl.Droid
{
public class Message
{
public string messages { get; set; }
}
}
This is the msg Adapter:
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;
namespace Dribl.Droid
{
class MsgAdapter : BaseAdapter<Message>
{
private List<Message> msgItems;
private Context msgContext;
public MsgAdapter(Context Context, List<Message> Items)
{
msgItems = Items;
msgContext = Context;
}
public override int Count
{
get { return msgItems.Count; }
}
public override long GetItemId(int position)
{
return position;
}
public override Message this[int position]
{
get { return msgItems[position]; }
}
public override View GetView(int position, View convertView, ViewGroup parent)
{
View row = convertView;
if (row == null)
{
row = LayoutInflater.From(msgContext).Inflate(Resource.Layout.msgCell, parent, false);
}
TextView message = row.FindViewById<TextView>(Resource.Id.message);
message.Text = msgItems[position].messages;
return row;
}
}
}

List<Message> message = JsonConvert.DeserializeObject<List<Message>>(json);
message is already a list of messages List<Message> so you don't need to create a new one. Just pass this object to the adapter constructor.
You can remove this part:
msgItems = new List<Message>();
for (int c = 0; c < message.Count; c++)
{
msgItems.Add(message[c].message);
}
But in case you wanna hold the list of message you just need to:
msgItems = messages;
Then creating you adapter object:
msgAdapter adapter = new msgAdapter(this, message);
or you can also
var adapter = new msgAdapter(this, message);
and add the adapter:
msgListview.Adapter = adapter;
Notes:
Change the message variable to messages since this contains more than one message.
msgAdapter change the name to MsgAdapter (First letter in capital) this way you won't have problems finding out when it's the class and when it's the object.
UPDATE:
You have an error in the GetView method of your adapter.
You need to indicate the parent when inflating the row:
row = LayoutInflater.From(msgContext).Inflate(Resource.Layout.msgCell, parent, false);

How to Reset a Xamarin forms Navigation stack from a Xamarin droid Assist activity

Helo I am working on adding an assist feature to my app that when the user holds down on the home button an android activity opens with cards that the user can click on that then opens the xamarin forms page in question for example when the math card is clicked the MathPage xamarin forms page opens this works but if I have the xamarin forms app running in the background it loads the home screen layout regardless of what button i click. If I close the xamarin forms app from multitasking and hold down on the home button and click on the math card it will open the MathPage.
heres my android Activity code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Xamarin.Forms.Platform.Android;
namespace Appname.Droid
{
[Activity(LaunchMode = LaunchMode.SingleInstance, Theme = "#style/Theme.Transparent")]
[IntentFilter(new[] { Intent.ActionAssist }, Categories = new[] { Intent.CategoryDefault })]
public class ToolBelt : Activity
{
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
// Set our view from the "main" layout resource
SetContentView(Resource.Layout.ToolBelt);
}
//Code That Opens The Math Part!
[Java.Interop.Export("math")] // The value found in android:onClick attribute.
public void btnOneClick4(View v) // Does not need to match value in above attribute.
{
var intent = new Intent(ApplicationContext, typeof(MainActivity));
intent.PutExtra("page", "Math");
StartActivity(intent);
}
//Code That Opens The Science Part!
[Java.Interop.Export("science")] // The value found in android:onClick attribute.
public void btnOneClick9(View v) // Does not need to match value in above attribute.
{
var intent = new Intent(ApplicationContext, typeof(MainActivity));
intent.PutExtra("page", "Science");
StartActivity(intent);
}
//Code That Opens The Handwriting Part!
[Java.Interop.Export("english")] // The value found in android:onClick attribute.
public void btnOneClick10(View v) // Does not need to match value in above attribute.
{
var intent = new Intent(ApplicationContext, typeof(MainActivity));
intent.PutExtra("page", "Handwriten");
StartActivity(intent);
}
//Code That Opens The Flascards Part!
[Java.Interop.Export("flashcard")] // The value found in android:onClick attribute.
public void btnOneClick11(View v) // Does not need to match value in above attribute.
{
var intent = new Intent(ApplicationContext, typeof(MainActivity));
intent.PutExtra("page", "Flashcards");
StartActivity(intent);
}
//Code That Opens The Internet App!
[Java.Interop.Export("web")] // The value found in android:onClick attribute.
public void btnOneClick8(View v) // Does not need to match value in above attribute.
{
var uri = Android.Net.Uri.Parse("http://www.google.com");
var intent = new Intent(Intent.ActionView, uri);
StartActivity(intent);
}
//Code That Opens The Gmail App!
[Java.Interop.Export("email")] // The value found in android:onClick attribute.
public void btnOneClick3(View v) // Does not need to match value in above attribute.
{
var intent = PackageManager.GetLaunchIntentForPackage("com.google.android.gm");
StartActivity(intent);
}
//Code That Opens The Books App!
[Java.Interop.Export("books")] // The value found in android:onClick attribute.
public void btnOneClick5(View v) // Does not need to match value in above attribute.
{
var intent = PackageManager.GetLaunchIntentForPackage("com.google.android.apps.books");
StartActivity(intent);
}
}
}
here's the MainActivity droid code:
using System;
using Android.App;
using Android.Content;
using Android.Content.PM;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using System.Collections.Generic;
using AppName.Droid;
using AppName.Data;
[assembly: Xamarin.Forms.Dependency(typeof(MainActivity))]
namespace AppName.Droid
{
[Activity(Label = "AppName", Icon = "#drawable/ic_launcher", Theme = "#style/MyTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]
public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity, SchoolTools.PackageInterface
{
protected override void OnCreate(Bundle savedInstanceState)
{
TabLayoutResource = Resource.Layout.Tabbar;
ToolbarResource = Resource.Layout.Toolbar;
base.OnCreate(savedInstanceState);
global::Xamarin.Forms.Forms.Init(this, savedInstanceState);
var page = Intent.GetStringExtra("page");
LoadApplication(new App(page));
}
public IList<Apps> GetInstalledApps()
{
IList<Apps> apps = new List<Apps>();
var pkgInfos = global::Xamarin.Forms.Forms.Context.PackageManager.GetInstalledPackages(PackageInfoFlags.Activities);
foreach(var pi in pkgInfos)
{
// skip system packages
if (pi.ApplicationInfo.DataDir.StartsWith("/data/user/"))
{
Apps app = new Apps(pi.ApplicationInfo.LoadLabel(global::Xamarin.Forms.Forms.Context.PackageManager).ToString(), pi.PackageName);
if (!apps.Contains(app))
{
apps.Add(app);
}
}
}
return apps;
}
public bool Launch(string package)
{
var intent = Application.Context.PackageManager.GetLaunchIntentForPackage(package);
bool retVal = IsIntentAvailable(intent);
if (retVal)
{
intent.AddFlags(ActivityFlags.NewTask);
Application.Context.StartActivity(intent);
}
return retVal;
}
private static bool IsIntentAvailable(Intent intent)
{
return intent != null && Application.Context.PackageManager.QueryIntentActivities(intent, 0).Count != 0;
}
}
}
heres my app.cs code:
using System;
using Xamarin.Forms;
namespace AppName
{
public class App : Application
{
public App(string pageName = "AppNameHome")
{
switch (pageName)
{
case "Math":
MainPage = new NavigationPage(new MathPage());
break;
case "Science":
MainPage = new NavigationPage(new Science.ScienceToolsPage());
break;
case "Handwriten":
MainPage = new NavigationPage(new Handwriting.HandwritingToolsPage());
break;
case "Flashcards":
MainPage = new NavigationPage(new Flashcards.FlashCardHome());
break;
default:
MainPage = new NavigationPage(new AppNameHome());
break;
}
}
protected override void OnStart()
{
// Handle when your app starts
}
protected override void OnSleep()
{
// Handle when your app sleeps
}
protected override void OnResume()
{
// Handle when your app resumes
}
}
}
any help would be amazing!
Thanks in advance :)

I figured out the problem i needed to add SingleInstance to the main activity as well is nohistory = true heres the code needed to fix this issue:
[Activity(LaunchMode = LaunchMode.SingleInstance, NoHistory = true,
Label = "AppName", Icon = "#drawable/ic_launcher", Theme = "#style/MyTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation)]

How to get the user location based on mobile sim network in android in c#"?

I want to get the user's current location (latitude and longitude) always using Sim-based network only, not by using any other networks (like WiFi, Mobile Data, GPS and other Network and even all these are in Disabled mode in mobile). Not necessarily exact location but even approximate location.
Is there any possibility to get it? If any of you can explain and include code; I searched in Google but did not get the correct related answer.
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Android.Locations;
using Android.Util;
using System;
using System.Collections.Generic;
using System.Text;
using System.Linq;
using System.Xml.Linq;
using System.Threading;
namespace GPS_Android
{
[Activity(Label = "GPS_Android", MainLauncher = true, Icon = "#drawable/icon")]
public class MainActivity : Activity,ILocationListener
{
private Location _currentLocation;
private LocationManager _locationManager;
private TextView _locationText;
private TextView _addressText;
private string _locationProvider;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
_addressText = FindViewById<TextView>(Resource.Id.address_text);
_locationText = FindViewById<TextView>(Resource.Id.location_text);
FindViewById<TextView>(Resource.Id.get_address_button).Click += AddressButton_OnClick;
InitializeLocationManager();
}
public void InitializeLocationManager()
{
_locationManager = (LocationManager)GetSystemService(LocationService);
Criteria criteriaForLocationService = new Criteria
{
Accuracy = Accuracy.Fine
};
IList<string> acceptableLocationProviders = _locationManager.GetProviders(criteriaForLocationService, true);
if (acceptableLocationProviders.Any())
{
_locationProvider = acceptableLocationProviders.First();
}
else
{
_locationProvider = String.Empty;
}
}
protected override void OnResume()
{
base.OnResume();
_locationManager.RequestLocationUpdates(_locationProvider, 0, 0, this);
}
protected override void OnPause()
{
base.OnPause();
_locationManager.RemoveUpdates(this);
}
async void AddressButton_OnClick(object sender, EventArgs eventArgs)
{
if (_currentLocation == null)
{
_addressText.Text = "Can't determine the current location.";
return;
}
Geocoder geocoder = new Geocoder(this);
IList<Address> addressList = await geocoder.GetFromLocationAsync(_currentLocation.Latitude, _currentLocation.Longitude, 10);
Address address = addressList.FirstOrDefault();
if (address != null)
{
StringBuilder deviceAddress = new StringBuilder();
for (int i = 0; i < address.MaxAddressLineIndex; i++)
{
deviceAddress.Append(address.GetAddressLine(i))
.AppendLine(",");
}
_addressText.Text = deviceAddress.ToString();
}
else
{
_addressText.Text = "Unable to determine the address.";
}
}
public void OnLocationChanged(Location location)
{
_currentLocation = location;
if (_currentLocation == null)
{
_locationText.Text = "Unable to determine your location.";
}
else
{
_locationText.Text = String.Format("{0},{1}", _currentLocation.Latitude, _currentLocation.Longitude);
}
}
public void OnProviderDisabled(string provider) { }
public void OnProviderEnabled(string provider) { }
public void OnStatusChanged(string provider, Availability status, Bundle extras) { }
}
}

You can use LocationManager.NETWORK_PROVIDER to get Latitude and Longitude without opening GPS
btnNWShowLocation.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View arg0) {
Location nwLocation = appLocationService
.getLocation(LocationManager.NETWORK_PROVIDER);
if (nwLocation != null) {
double latitude = nwLocation.getLatitude();
double longitude = nwLocation.getLongitude();
Toast.makeText(
getApplicationContext(),
"Mobile Location (NW): \nLatitude: " + latitude
+ "\nLongitude: " + longitude,
Toast.LENGTH_LONG).show();
} else {
showSettingsAlert("NETWORK");
}
}
});