Die Aktivität kann nicht instanziiert werden: Die Klasse com.pz.mediatonmessanger.ChatDialogActivity hat keinen Nullargumentkonstruktor

Question

Fehler und Chat Aktivitätsdialog sieht wie folgt aus.

04-09 09:03:23.509 2722-2722/com.pz.mediatonmessanger E/AndroidRuntime: FATAL EXCEPTION: main 
    Process: com.pz.mediatonmessanger, PID: 2722 
    java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.pz.mediatonmessanger/com.pz.mediatonmessanger.ChatDialogActivity}: java.lang.InstantiationException: class com.pz.mediatonmessanger.ChatDialogActivity has no zero argument constructor 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2209) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
    at android.app.ActivityThread.access$800(ActivityThread.java:144) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:135) 
    at android.app.ActivityThread.main(ActivityThread.java:5221) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at java.lang.reflect.Method.invoke(Method.java:372) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 
    Caused by: java.lang.InstantiationException: class com.pz.mediatonmessanger.ChatDialogActivity has no zero argument constructor 
    at java.lang.Class.newInstance(Class.java:1563) 
    at android.app.Instrumentation.newActivity(Instrumentation.java:1065) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2199) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
    at android.app.ActivityThread.access$800(ActivityThread.java:144) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:135) 
    at android.app.ActivityThread.main(ActivityThread.java:5221) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at java.lang.reflect.Method.invoke(Method.java:372) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 
    Caused by: java.lang.NoSuchMethodException: <init> [] 
    at java.lang.Class.getConstructor(Class.java:531) 
    at java.lang.Class.getDeclaredConstructor(Class.java:510) 
    at java.lang.Class.newInstance(Class.java:1561) 
    at android.app.Instrumentation.newActivity(Instrumentation.java:1065) 
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2199) 
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2360) 
    at android.app.ActivityThread.access$800(ActivityThread.java:144) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1278) 
    at android.os.Handler.dispatchMessage(Handler.java:102) 
    at android.os.Looper.loop(Looper.java:135) 
    at android.app.ActivityThread.main(ActivityThread.java:5221) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at java.lang.reflect.Method.invoke(Method.java:372) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694) 

-Code

package com.pz.mediatonmessanger; 

import android.app.ProgressDialog; 
import android.content.Intent; 
import android.support.design.widget.FloatingActionButton; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.View; 
import android.widget.ListView; 

import com.pz.mediatonmessanger.Adapter.ChatDialogsAdapter; 
import com.quickblox.auth.QBAuth; 
import com.quickblox.auth.session.BaseService; 
import com.quickblox.auth.session.QBSession; 
import com.quickblox.chat.QBChatService; 
import com.quickblox.chat.QBRestChatService; 
import com.quickblox.chat.model.QBChatDialog; 
import com.quickblox.core.QBEntityCallback; 
import com.quickblox.core.exception.BaseServiceException; 
import com.quickblox.core.exception.QBResponseException; 
import com.quickblox.core.request.QBRequestBuilder; 
import com.quickblox.core.request.QBRequestGetBuilder; 
import com.quickblox.users.model.QBUser; 

import java.util.ArrayList; 




public class ChatDialogActivity extends AppCompatActivity { 

    FloatingActionButton floatingActionButton; 
    ListView lstChatDialogs; 


    public ChatDialogActivity(FloatingActionButton floatingActionButton) { 
     this.floatingActionButton = floatingActionButton; 
    } 

    public ChatDialogActivity(ListView lstChatDialogs) { 
     this.lstChatDialogs = lstChatDialogs; 
    } 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_chat_dialog); 

     createSessionForChat(); 

     lstChatDialogs = (ListView)findViewById(R.id.lstChatDialogs); 

     loadChatDialogs(); 



     floatingActionButton = (FloatingActionButton) findViewById(R.id.chatdialog_adduser); 

     floatingActionButton.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent intent = new Intent(ChatDialogActivity.this, ListUsersActivity.class); 
       startActivity(intent); 
      } 
     }); 
    } 

    private void loadChatDialogs() { 

     QBRequestGetBuilder requestBuilder = new QBRequestGetBuilder(); 
     requestBuilder.setLimit(100); 

     QBRestChatService.getChatDialogs(null,requestBuilder).performAsync(new QBEntityCallback<ArrayList<QBChatDialog>>() { 
      @Override 
      public void onSuccess(ArrayList<QBChatDialog> qbChatDialogs, Bundle bundle) { 

       //Kod 
       ChatDialogsAdapter adapter = new ChatDialogsAdapter(getBaseContext(),qbChatDialogs); 
       lstChatDialogs.setAdapter(adapter); 
       adapter.notifyDataSetChanged(); 
      } 

      @Override 
      public void onError(QBResponseException e) { 
        Log.e("Błąd",e.getMessage()); 
      } 
     }); 
    } 

    private void createSessionForChat() { 
     final ProgressDialog mDialog = new ProgressDialog(ChatDialogActivity.this); 
     mDialog.setMessage("Ładowanie..."); 
     mDialog.setCanceledOnTouchOutside(false); 
     mDialog.show(); 

     String user,password; 
     user = getIntent().getStringExtra("user"); 
     password = getIntent().getStringExtra("password"); 

     final QBUser qbUser = new QBUser(user,password); 
     QBAuth.createSession(qbUser).performAsync(new QBEntityCallback<QBSession>() { 
      @Override 
      public void onSuccess(QBSession qbSession, Bundle bundle) { 
       qbUser.setId(qbSession.getUserId()); 
       try { 
        qbUser.setPassword(BaseService.getBaseService().getToken()); 
       } catch (BaseServiceException e) { 
        e.printStackTrace(); 
       } 

       QBChatService.getInstance().login(qbUser, new QBEntityCallback() { 
        @Override 
        public void onSuccess(Object o, Bundle bundle) { 
         mDialog.dismiss(); 
        } 

        @Override 
        public void onError(QBResponseException e) { 
         Log.e("Błąd",""+e.getMessage()); 
        } 
       }); 
      } 

      @Override 
      public void onError(QBResponseException e) { 

      } 
     }); 

    } 
} 

Answer 1

Aktivitäten nicht einen Konstruktor in Android haben, können Sie sie nicht erstellen, wie Sie mit anderen Klassen zu tun. Sie werden vom System instanziiert, Sie müssen sie nur mit context.startActivity(intent) starten.

alle Konstrukteure von dieser Aktivität entfernen und einen Verweis auf die Ansichten mit findViewById und Sie sollten in Ordnung