Xamarin - phone call events / state - xamarin

Question

I'm very new to Xamarin and mobile development, but have an experience with C#.
Following is my attempt to take some code from the web and adjusting it to Xamarin.
The code fails on exception, while placing a call.
I, actually, can't reach breakpoints in my CallReceiver / PhonecallReceiver classes.
I'm running VS2017 community, API23, arm phone.
What I'm missing?
MainActivity:
using System;
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Android.Telephony;
using Java.Lang;
using String = System.String;
using System.Collections.Generic;
using Java.Util;
using Javax.Security.Auth;
namespace CallManipulation
{
public abstract class PhonecallReceiver : BroadcastReceiver
{
private static CallState lastState = CallState.Idle;
private static DateTime callStartTime;
private static bool isIncoming;
private static String savedNumber;
public override void OnReceive(Context context, Intent intent)
{
if (intent.Action.Equals("android.intent.action.NEW_OUTGOING_CALL"))
{
savedNumber = intent.Extras.GetString("android.intent.extra.PHONE_NUMBER");
}
else
{
String stateStr = intent.Extras.GetString(TelephonyManager.ExtraState);
String number = intent.Extras.GetString(TelephonyManager.ExtraIncomingNumber);
CallState state = CallState.Idle;
if (stateStr.Equals(TelephonyManager.ExtraStateIdle))
{
state = CallState.Idle;
}
else if (stateStr.Equals(TelephonyManager.ExtraStateOffhook))
{
state = CallState.Offhook;
}
else if (stateStr.Equals(TelephonyManager.ExtraStateRinging))
{
state = CallState.Ringing;
}
OnCallStateChanged(context, state, number);
}
}
protected virtual void onIncomingCallStarted(Context ctx, String number, DateTime start) { }
protected virtual void onOutgoingCallStarted(Context ctx, String number, DateTime start) { }
protected virtual void onIncomingCallEnded(Context ctx, String number, DateTime start, DateTime end) { }
protected virtual void onOutgoingCallEnded(Context ctx, String number, DateTime start, DateTime end) { }
protected virtual void onMissedCall(Context ctx, String number, DateTime start) { }
public void OnCallStateChanged(Context context, CallState state, string number)
{
if (lastState == state)
return;
switch (state)
{
case CallState.Ringing:
isIncoming = true;
callStartTime = new DateTime().Date;
savedNumber = number;
onIncomingCallStarted(context, number, callStartTime);
break;
case CallState.Offhook:
if (lastState != CallState.Ringing)
{
isIncoming = false;
callStartTime = new DateTime().Date;
onOutgoingCallStarted(context, savedNumber, callStartTime);
}
break;
case CallState.Idle:
if (lastState == CallState.Ringing)
onMissedCall(context, savedNumber, callStartTime);
else if (isIncoming)
onIncomingCallEnded(context, savedNumber, callStartTime, new DateTime().Date);
else
onOutgoingCallEnded(context, savedNumber, callStartTime, new DateTime().Date);
break;
}
lastState = state;
}
}
public class CallReceiver : PhonecallReceiver
{
protected override void onIncomingCallStarted(Context ctx, string number, DateTime start)
{
}
protected override void onOutgoingCallStarted(Context ctx, string number, DateTime start)
{
}
protected override void onIncomingCallEnded(Context ctx, string number, DateTime start, DateTime end)
{
}
protected override void onOutgoingCallEnded(Context ctx, string number, DateTime start, DateTime end)
{
}
protected override void onMissedCall(Context ctx, string number, DateTime start)
{
}
}
[Activity(Label = "CallManipulation", MainLauncher = true, Icon = "#drawable/icon")]
public class MainActivity : Activity
{
int count = 1;
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
}
}
}
Manifest:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="CallManipulation.CallManipulation" android:versionCode="1" android:versionName="1.0">
<uses-sdk android:minSdkVersion="16" />
<uses-permission android:name="android.permission.READ_PHONE_STATE" />
<uses-permission android:name="android.permission.PROCESS_OUTGOING_CALLS"/>
<application android:label="CallManipulation">
<!--This part is inside the application-->
<receiver android:name=".CallReceiver" >
<intent-filter>
<action android:name="android.intent.action.PHONE_STATE" />
</intent-filter>
<intent-filter>
<action android:name="android.intent.action.NEW_OUTGOING_CALL" />
</intent-filter>
</receiver>
</application>
</manifest>
Output window:
08-01 15:53:29.279 D/Mono ( 2601): [0x9f7fd930] worker starting
08-01 15:53:29.308 D/Mono ( 2601): DllImport searching in: '__Internal' ('(null)').
08-01 15:53:29.308 D/Mono ( 2601): Searching for 'java_interop_jnienv_call_void_method_a'.
08-01 15:53:29.308 D/Mono ( 2601): Probing 'java_interop_jnienv_call_void_method_a'.
08-01 15:53:29.308 D/Mono ( 2601): Found as 'java_interop_jnienv_call_void_method_a'.
08-01 15:53:29.316 E/AndroidRuntime( 2601): FATAL EXCEPTION: main
08-01 15:53:29.316 E/AndroidRuntime( 2601): Process: CallManipulation.CallManipulation, PID: 2601
08-01 15:53:29.316 E/AndroidRuntime( 2601): java.lang.RuntimeException: Unable to instantiate receiver CallManipulation.CallManipulation.CallReceiver: java.lang.ClassNotFoundException: Didn't find class "CallManipulation.CallManipulation.CallReceiver" on path: DexPathList[[zip file "/data/app/CallManipulation.CallManipulation-1/base.apk"],nativeLibraryDirectories=[/data/app/CallManipulation.CallManipulation-1/lib/arm, /data/app/CallManipulation.CallManipulation-1/base.apk!/lib/armeabi-v7a, /vendor/lib, /system/lib]]
08-01 15:53:29.316 E/AndroidRuntime( 2601): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2706)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at android.app.ActivityThread.-wrap14(ActivityThread.java)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1421)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at android.os.Handler.dispatchMessage(Handler.java:102)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at android.os.Looper.loop(Looper.java:148)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at android.app.ActivityThread.main(ActivityThread.java:5417)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at java.lang.reflect.Method.invoke(Native Method)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
08-01 15:53:29.316 E/AndroidRuntime( 2601): Caused by: java.lang.ClassNotFoundException: Didn't find class "CallManipulation.CallManipulation.CallReceiver" on path: DexPathList[[zip file "/data/app/CallManipulation.CallManipulation-1/base.apk"],nativeLibraryDirectories=[/data/app/CallManipulation.CallManipulation-1/lib/arm, /data/app/CallManipulation.CallManipulation-1/base.apk!/lib/armeabi-v7a, /vendor/lib, /system/lib]]
08-01 15:53:29.316 E/AndroidRuntime( 2601): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at java.lang.ClassLoader.loadClass(ClassLoader.java:511)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at java.lang.ClassLoader.loadClass(ClassLoader.java:469)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at android.app.ActivityThread.handleReceiver(ActivityThread.java:2701)
08-01 15:53:29.316 E/AndroidRuntime( 2601): ... 8 more
08-01 15:53:29.316 E/AndroidRuntime( 2601): Suppressed: java.lang.ClassNotFoundException: CallManipulation.CallManipulation.CallReceiver
08-01 15:53:29.316 E/AndroidRuntime( 2601): at java.lang.Class.classForName(Native Method)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at java.lang.BootClassLoader.findClass(ClassLoader.java:781)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at java.lang.BootClassLoader.loadClass(ClassLoader.java:841)
08-01 15:53:29.316 E/AndroidRuntime( 2601): at java.lang.ClassLoader.loadClass(ClassLoader.java:504)
08-01 15:53:29.316 E/AndroidRuntime( 2601): ... 10 more
08-01 15:53:29.316 E/AndroidRuntime( 2601): Caused by: java.lang.NoClassDefFoundError: Class not found using the boot class loader; no stack trace available