android stüdyosu facebook etkinliği ile hata

Question

Temel facebook aktivty geliştirmeye çalışıyorum ve uygulama kullanıcı adı ve ekranda görüntüleyecektir ama ben bir tür FATAL EXCEPTION karşı karşıyayım: ana hata tam set benim sağladık Bildiri dosyasının, sınıf dosyası, xml dosyası ve Logcat hata ile başlayan kodlar, yardımın oldukça aşağıda verilen kod aşağıdaki kod benim bildirim dosya

<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
package="com.example.world.trialwithmugaputhagam"> 

<uses-permission android:name="android.permission.INTERNET" /> 

<application 
    android:name=".MyApplicatioon" 
    android:allowBackup="true" 
    android:icon="@mipmap/ic_launcher" 
    android:label="@string/app_name" 
    android:supportsRtl="true" 
    android:theme="@style/AppTheme"> 
    <meta-data 
     android:name="com.facebook.sdk.ApplicationId" 
     android:value="@string/app_id" /> 

    <activity android:name=".MainActivity"> 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 

      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
    <activity 
     android:name="com.facebook.FacebookActivity" 
     android:configChanges="keyboard|keyboardHidden|screenLayout|screenSize|orientation" 
     android:label="@string/app_name" 
     android:theme="@android:style/Theme.Translucent.NoTitleBar" /> 
    <activity android:name=".MainFragment" /> 
</application> 

olduğunu

gereklidir Ben kodunun altına sınıf dosyası yetkilendirme yalnızca var olan ben de mTextDetails atamış ama imlecini o değeri aşağıdaki kod benim XML dosya

olduğunu

import android.os.Bundle; 
import android.app.Fragment; 
import android.content.Intent; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.TextView; 
import com.facebook.AccessToken; 
import com.facebook.CallbackManager; 
import com.facebook.FacebookCallback; 
import com.facebook.FacebookException; 
import com.facebook.FacebookSdk; 
import com.facebook.Profile; 
import com.facebook.login.LoginResult; 
import com.facebook.login.widget.LoginButton; 

public class MainActivity extends Fragment { 

private TextView mTextDetails; 
private CallbackManager mcallbackManager; 

@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    FacebookSdk.sdkInitialize(getActivity().getApplicationContext()); 
    mcallbackManager=CallbackManager.Factory.create(); 
} 
@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
    return inflater.inflate(R.layout.activity_main,container,false); 
} 


private FacebookCallback<LoginResult> mcallback = new FacebookCallback<LoginResult>() { 
    @Override 
    public void onSuccess(LoginResult loginResult) { 
     AccessToken accessToken = loginResult.getAccessToken(); 
     Profile profile = Profile.getCurrentProfile(); 
     if (profile != null){ 
      mTextDetails.setText("Welcome "+ profile.getName()); 
     } 
    } 

    @Override 
    public void onCancel() { 

    } 

    @Override 
    public void onError(FacebookException error) { 

    } 
}; 



@Override 
public void onViewCreated(View view, Bundle savedInstanceState) { 
    super.onViewCreated(view, savedInstanceState); 
    LoginButton loginButton = (LoginButton) view.findViewById(R.id.login_button); 
    loginButton. setReadPermissions("user_friends"); 
    loginButton. setFragment(this); 
    loginButton.registerCallback(mcallbackManager, mcallback); 
} 

@Override 
public void onActivityResult(int requestCode, int resultCode, Intent data) { 
    super.onActivityResult(requestCode, resultCode, data); 
    mcallbackManager.onActivityResult(requestCode, resultCode, data); 
}} 

atanmamış söylemek

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:paddingBottom="@dimen/activity_vertical_margin" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
tools:context="com.example.world.trialwithmugaputhagam.MainActivity"> 

<TextView 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="@string/Welcome" 
    android:id="@+id/text_details" 
    android:layout_centerHorizontal="true" 
    android:layout_centerVertical="true" 
    android:layout_above="@+id/login_button"/> 

<com.facebook.login.widget.LoginButton 
    android:id="@+id/login_button" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:layout_gravity="center_horizontal" 
    android:layout_marginTop="30dp" 
    android:layout_marginBottom="30dp" 
    android:layout_centerInParent="true"/></RelativeLayout> 

Logcat hata yanlış hizalama için üzgünüm.

FATAL EXCEPTION: main 
java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.world.trialwithmugaputhagam/com.example.world.trialwithmugaputhagam.MainActivity}: java.lang.ClassCastException: com.example.world.trialwithmugaputhagam.MainActivity cannot be cast to android.app.Activity 
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2137) 
                         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
                         at android.app.ActivityThread.access$600(ActivityThread.java:141) 
                         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
                         at android.os.Handler.dispatchMessage(Handler.java:99) 
                         at android.os.Looper.loop(Looper.java:137) 
                         at android.app.ActivityThread.main(ActivityThread.java:5103) 
                         at java.lang.reflect.Method.invokeNative(Native Method) 
                         at java.lang.reflect.Method.invoke(Method.java:525) 
                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
                         at dalvik.system.NativeStart.main(Native Method) 
                        Caused by: java.lang.ClassCastException: com.example.world.trialwithmugaputhagam.MainActivity cannot be cast to android.app.Activity 
                         at android.app.Instrumentation.newActivity(Instrumentation.java:1061) 
                         at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2128) 
                         at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)  
                         at android.app.ActivityThread.access$600(ActivityThread.java:141)  
                         at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)  
                         at android.os.Handler.dispatchMessage(Handler.java:99)  
                         at android.os.Looper.loop(Looper.java:137)  
                         at android.app.ActivityThread.main(ActivityThread.java:5103)  
                         at java.lang.reflect.Method.invokeNative(Native Method)  
                         at java.lang.reflect.Method.invoke(Method.java:525)  
                         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)  
                         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)  
                         at dalvik.system.NativeStart.main(Native Method) 

Answer 1

Eğer Fragment den MainActivity uzanan çünkü. Böylece, MainActivity, aslında bir Activity değil, bir Fragment. Activity veya Activity alt sınıflarını genişletin. Bunun gibi

:

MainActivity extends AppCompatActivity

Düzenleme 1: (açıklamalara dayanarak):

Sen mTextDetails başlatılmış değil; Activity 'ın onCreate böyle yapmaya çalışacağım:

mTextDetails = (TextView)findViewById(R.id.text_view_id);