Android Studio - PopupMenu.OnMenuItemClickListener Problem

Question

Ich schreibe eine mobile Anwendung und habe ein Popup-Menü an ein ImageButton über die OnClick-Methode der Schaltfläche angefügt.

menu_lilac.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View view) { 
      showPopup(view); 

     } 
    }); 

Ich versuche es so drücken Sie den Menüpunkt zu machen Umleitungen an die betreffende Aktivität (in der switch-Anweisung am Ende). Der Fehler, den ich erhalte, ist Error: (23, 8) error: MainActivity ist nicht abstrakt und überschreibt nicht die abstrakte Methode onMenuItemClick (MenuItem) in OnMenuItemClickListener.

public void showPopup(View view) { 
    PopupMenu popup = new PopupMenu(this, view); 
    MenuInflater inflater = popup.getMenuInflater(); 
    inflater.inflate(R.menu.mainmenu, popup.getMenu()); 
    MenuItem item = (MenuItem) popup.getMenu(); 
    popup.show(); 

    //Intent to Tasks Activity 
    final Intent toTasks = new Intent(this, TasksActivity.class); 

    //Intent to Distractions Activity 
    final Intent toDist = new Intent(this, DistractionsActivity.class); 

    //Intent to Settings Activity 
    final Intent toSett = new Intent(this, SettingsActivity.class); 

    popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener(){ 
     @Override 
     public boolean onMenuItemClick(MenuItem item) { 
      switch (item.getItemId()) { 
       case R.id.Home: 
        return true; 

       case R.id.Tasks: 
        startActivity(toTasks); 
        return true; 

       case R.id.Distractions: 
        startActivity(toDist); 
        return true; 

       case R.id.Settings: 
        startActivity(toSett); 
        return true; 

       default: 
        return false; 
      } 

    } 

    }); 
} 

Was mache ich falsch? Ich versuchte, die OnMenuItemClickListener in einer anderen Art und Weise, wie

PopupMenu.OnMenuItemClickListener listener = PopupMenu.OnMenuItemClickListener(){ 


    } 

aber Zuhörer nie benutzt wird initialisiert und die App stürzt ab, wenn eine der Menütasten gedrückt werden.

Voll MainActivity Klasse:

import android.app.Activity; 
import android.app.PendingIntent; 
import android.content.Context; 
import android.content.Intent; 
import android.os.Bundle; 
import android.os.Handler; 
import android.os.SystemClock; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.widget.Button; 
import android.widget.ImageButton; 
import android.widget.NumberPicker; 
import android.widget.PopupMenu; 
import android.widget.TextView; 
import android.widget.Toast; 
import android.widget.ListView; 

public class MainActivity extends Activity implements PopupMenu.OnMenuItemClickListener { 

//Creation of used objects 
//Button, Button, TextView, Handler, AlarmManager, NumberPicker, Pending Intent 
//Context, TextView, Button 

Button startButton; 
Button stopButton; 
TextView timerValue; 
Handler customHandler = new Handler(); 
NumberPicker interval_length; 
PendingIntent pending_intent; 
Context context; 
TextView checker; 
ImageButton menu_lilac; 
Intent toDist; 
Intent toSett; 
Intent toTasks; 

//Creation of variables 
long timeInMilliseconds = 0L; 
long updatedTime = 0L; 
long startTime = 0L; 
int picked_value; 
private static int minValueInterval = 1; 
private static int maxValueInterval = 60; 
int final_interval; 

//On create function initialises the layout 
@Override 
protected void onCreate(Bundle savedInstanceState) { 
    //Creation of main GUI layout 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    this.context = this; 
} 


@Override 
protected void onStart() { 
    super.onStart(); 

    //Initialise number picker 
    interval_length = (NumberPicker) findViewById(R.id.interval_length); 

    //Set minimum value (minutes) 
    interval_length.setMinValue(minValueInterval); 
    //Set maximum value (minutes) 
    interval_length.setMaxValue(maxValueInterval); 
    //Set currently displayed value (minutes) 
    interval_length.setValue(20); 

    //Initialise listener to listen for a value change on the number picker 
    interval_length.setOnValueChangedListener(new NumberPicker.OnValueChangeListener() { 
     @Override 
     public void onValueChange(NumberPicker picker, int oldVal, int newVal) { 
      //Replace variable picked_value with the new value of the number picker 
     picked_value = interval_length.getValue() - 1; 
     } 
    }); 

    //Initialise timerValue text box 
    timerValue = (TextView) findViewById(R.id.timerValue); 

    //Initialise start button 
    startButton = (Button) findViewById(R.id.startButton); 

    //Initialise instance of stop button 
    stopButton = (Button) findViewById(R.id.stopButton); 

    //Initialise instance of menu button 
    menu_lilac = (ImageButton) findViewById(R.id.menu_lilac); 

    //Initialise checker text box 
    checker = (TextView) findViewById(R.id.checker); 

    //Menu button onClickListener 
    menu_lilac.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View view) { 
      showPopup(view); 

     } 
    }); 

      //Start button OnClickListener 
    startButton.setOnClickListener(new View.OnClickListener() { 
     //On start begin counting up in milliseconds. 
     //Reset timer every time Start button is pressed. 
     public void onClick(View view) { 
      timerValue.setText("00:00"); 
      startTime = SystemClock.uptimeMillis(); 
      customHandler.postDelayed(updateTimerThread, 0); 

      //Set text box to print a message displaying when the alarm is for 
      checker.setText("The alarm has been set for " + picked_value + " minutes from now!"); 

      //Make pop-up toast notification 
      Toast.makeText(context,"Alarm on!", Toast.LENGTH_LONG).show(); 
     } 
    }); 

    //Calculation of picked interval length (from minutes) to milliseconds 
    final_interval = picked_value * 60 * 1000; 
    if (timerValue.equals(picked_value+":00")) { 
     alarm_manager.set(AlarmManager.RTC_WAKEUP, timeInMilliseconds, pending_intent); 
    } 

    //Initialise Stop button OnClickListener 
    stopButton.setOnClickListener(new View.OnClickListener() { 
     //On click stop updating timer thread and reset value to 00:00 
     public void onClick(View view) { 
      customHandler.removeCallbacks(updateTimerThread); 
      timerValue.setText("00:00"); 

      //print message to notify user of alarm being cancelled 
      checker.setText("The alarm has been cancelled!"); 
      //Make toast notification to say alarm cancelled 
      Toast.makeText(context,"Alarm off!", Toast.LENGTH_LONG).show(); 
     } 
    }); 
} 
//Creates a runnable to update the timer 
private Runnable updateTimerThread = new Runnable() { 
    public void run() { 
     //Takes time in milliseconds from the system clock 
     timeInMilliseconds = SystemClock.uptimeMillis() - startTime; 
     updatedTime = timeInMilliseconds; 
     //Converts milliseconds to seconds and minutes 
     int secs = (int) (updatedTime/1000); 
     int mins = secs/60; 
     secs = secs % 60; 
     int milliseconds = (int) (updatedTime % 1000); 
     //Updates timerValue to the formatted 00:00 (minutes:seconds) 
     timerValue.setText(String.format("%02d", mins) + ":" 
       + String.format("%02d", secs)); 
     customHandler.postDelayed(this, 0); 
    } 
}; 

public Runnable showPopup(View view) { 
    PopupMenu popup = new PopupMenu(this, view); 
    MenuInflater inflater = popup.getMenuInflater(); 
    inflater.inflate(R.menu.mainmenu, popup.getMenu()); 
    MenuItem item = (MenuItem) popup.getMenu(); 
    popup.show(); 

    //Intent to Tasks Activity 
    final Intent toTasks = new Intent(this, TasksActivity.class); 

    //Intent to Distractions Activity 
    final Intent toDist = new Intent(this, DistractionsActivity.class); 

    //Intent to Settings Activity 
    final Intent toSett = new Intent(this, SettingsActivity.class); 

    popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener(){ 
     @Override 
     public boolean onMenuItemClick(MenuItem item) { 
      switch (item.getItemId()) { 
       case R.id.Home: 
        return true; 

       case R.id.Tasks: 
        startActivity(toTasks); 
        return true; 

       case R.id.Distractions: 
        startActivity(toDist); 
        return true; 

       case R.id.Settings: 
        startActivity(toSett); 
        return true; 

       default: 
        return false; 
      } 

    } 

    }); 
} 

}

Answer 1

Fest! Ich habe die "implements PopupMenu.OnMenuItemClickListener" aus meiner Klassendeklaration entfernt und das PopupMenu erneut ausgeführt. Dieses Mal habe ich if-Anweisungen anstelle einer switch-Anweisung verwendet und anstelle von MenuInFlater habe ich einfach inflate() auf popup verwendet.

Dies sind die benötigten Importe:

import android.view.MenuItem; 
import android.widget.PopupMenu; 

Meine Klassendeklaration:

public class MainActivity extends Activity { 

Das sind meine Absichten:

//Intent to Tasks Activity 
    final Intent toTasks = new Intent(this, TasksActivity.class); 

    //Intent to Distractions Activity 
    final Intent toDist = new Intent(this, DistractionsActivity.class); 

    //Intent to Settings Activity 
    final Intent toSett = new Intent(this, SettingsActivity.class); 

Und das ist mein Popup-Menü.

//Menu button onClickListener 
    menu_lilac.setOnClickListener(new View.OnClickListener() { 
     public void onClick(View view) { 
      //create instance of PopupMenu 
      PopupMenu popup = new PopupMenu(getApplicationContext(), view); 
      //inflate menu with layout mainmenu 
      popup.inflate(R.menu.mainmenu); 
      popup.show(); 

      //Set on click listener for the menu 
      popup.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener() { 
       @Override 
       public boolean onMenuItemClick(MenuItem item) { 
        if (item.getItemId()== R.id.Home){ 
         Toast.makeText(context, "At home!", Toast.LENGTH_LONG).show(); 
        } 
        if (item.getItemId() == R.id.Tasks){ 
         startActivity(toTasks); 
        } 
        if (item.getItemId() == R.id.Distractions){ 
         startActivity(toDist); 
        } 
        if (item.getItemId() == R.id.Settings){ 
         startActivity(toSett); 
        } 
        return false; 
       } 
      }); 
     } 
    }); 

Answer 2

ich Grund sehe nicht, warum Sie eigentlich Schnittstelle PopupMenu.OnMenuItemClickListener in Ihrer Tätigkeit implementieren, aber wenn es Grund ist, müssen Sie Methoden dieser Schnittstelle implementieren.

Also im Grunde Sie must have implementation dieser Methode in MainActivity:

@Override 
public boolean onMenuItemClick(MenuItem item) { 
    return false; 
} 

auch hoffentlich Android Studio verwenden. Es sollte Sie über Fehler sagen und wenn Sie Zeiger auf Fehler setzen und klicken Sie auf "ALT + ENTER" Sie sehen Implementieren Sie Methoden Element im Menü, klicken Sie auf, die das Problem lösen wird.