無法啓動活動（java.lang.RuntimeException）

Question

我正在開發一個android應用程序，雖然沒有編譯錯誤，但在啓動它時沒有響應。我嘗試了幾件事，但都沒有奏效。當我添加第二個活動時，這個問題就開始了，但我試過刪除它，但仍然失敗。

清單：

<?xml version="1.0" encoding="utf-8"?> 
<manifest xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:tools="http://schemas.android.com/tools" 
    package="xxx.xxxx.xxx"> 
    <uses-permission android:name="android.permission.INTERNET" /> 
    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/> 
    <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" /> 
    <application 
     android:debuggable="false" 
     android:allowBackup="true" 
     android:icon="@mipmap/ic_launcher" 
     android:label="@string/app_name" 
     android:roundIcon="@mipmap/ic_launcher_round" 
     android:supportsRtl="true" 
     android:theme="@style/AppTheme"> 
      <receiver 
       android:name="xxx.xxx.xxx.Monitor" 
       android:enabled="true" 
       android:permission="android.permission.RECIEVE_BOOT_COMPLETED" > 
        <intent-filter> 
         <action android:name="android.intent.action.BOOT_COMPLETED" /> 
         <category android:name="android.intent.category.DEFAULT" /> 
        </intent-filter> 
      </receiver> 
     <activity android:name="com.xxx.xxx.MainActivity" 
       android:configChanges= "orientation|screenSize" 
       android:label="@string/app_name"> 
       <intent-filter> 
        <action android:name="android.intent.action.MAIN" /> 
        <category android:name="android.intent.category.LAUNCHER" /> 
       </intent-filter> 
     </activity> 
     <activity android:name="com.xxx.xxx.Ajustes" 
      android:configChanges= "orientation|screenSize" 
      android:label="@string/app_name"> 
     </activity> 
    </application> 
</manifest> 

搖籃的logcat的的

apply plugin: 'com.android.application' 

android { 
    compileSdkVersion 26 
    buildToolsVersion "26.0.0" 
    defaultConfig { 
     applicationId "xxx.xxxx.xxx" 
     minSdkVersion 14 
     targetSdkVersion 26 
     versionCode 1 
     versionName "1.0" 
     testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner" 
    } 
    buildTypes { 
     release { 
      minifyEnabled false 
      proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro' 
     } 
    } 
} 
dependencies { 
    compile fileTree(dir: 'libs', include: ['*.jar']) 
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', { 
     exclude group: 'com.android.support', module: 'support-annotations' 
    }) 
    compile 'com.android.support:appcompat-v7:26.+' 
    compile 'com.android.support.constraint:constraint-layout:1.0.2' 
    testCompile 'junit:junit:4.12' 
    compile 'org.jetbrains:annotations-java5:15.0' 
    compile 'com.android.support:design:26.+' 
} 

一部分;

07-18 12:36:05.414 3649-3649/? E/AndroidRuntime: FATAL EXCEPTION: main 
               Process: xxx.xxx.xxx, PID: 3649 
               java.lang.RuntimeException: Unable to start activity ComponentInfo{xxx.xxx.xxx/com.xxx.xxx.MainActivity}: android.util.AndroidRuntimeException: requestFeature() must be called before adding content 
                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646) 
                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707) 
                at android.app.ActivityThread.-wrap12(ActivityThread.java) 
                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460) 
                at android.os.Handler.dispatchMessage(Handler.java:102) 
                at android.os.Looper.loop(Looper.java:154) 
                at android.app.ActivityThread.main(ActivityThread.java:6077) 
                at java.lang.reflect.Method.invoke(Native Method) 
                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866) 
                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756) 
                Caused by: android.util.AndroidRuntimeException: requestFeature() must be called before adding content 
                at com.android.internal.policy.PhoneWindow.requestFeature(PhoneWindow.java:338) 
                at android.app.Activity.requestWindowFeature(Activity.java:3946) 
                at com.xxx.xxx.MainActivity.onCreate(MainActivity.java:52) 
                at android.app.Activity.performCreate(Activity.java:6662) 
                at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1118) 
                at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2599) 
                at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)  
                at android.app.ActivityThread.-wrap12(ActivityThread.java)  
                at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)  
                at android.os.Handler.dispatchMessage(Handler.java:102)  
                at android.os.Looper.loop(Looper.java:154)  
                at android.app.ActivityThread.main(ActivityThread.java:6077)  
                at java.lang.reflect.Method.invoke(Native Method)  
                at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:866)  
                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:756)  

在異常引用的線是

requestWindowFeature(Window.FEATURE_NO_TITLE); 

但評論它或改變其possition一直沒有解決的問題。

MainActivity：

public class MainActivity extends Activity 
{ 
    static WebView web; 
    static String etiqueta; 
    static String mensaje; 
    static String si; 
    Context context=this; 
    static SharedPreferences datos; 
    ImageButton boton; 
    static boolean paisES; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) 
    { 
     super.onCreate(savedInstanceState); 
    getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN); 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    setContentView(R.layout.activity_main); 


     web = (WebView) findViewById(R.id.webV); 

     paisES =("ES".equals(Locale.getDefault().getCountry())|| "es".equals(Locale.getDefault().getLanguage())); 


     //Verificar conexión 

     if (Conectividad.conectado(this)) 
     { 
      if(paisES) 
      { 
       etiqueta="https://www.xxx.xx/launcher/xxx-xx/?language=es_ES"; 
      } 
      else 
      { 
       etiqueta="https://www.xxx.xx/launcher/xxx-xx/?language=en_US"; 
      } 
     } 
     else 
     { 
      if(paisES) 
      { 
       etiqueta="https://www.xxx.xx/launcher/xxx-xx/?language=es_ES"; 
       mensaje="No tienes conexión ¿Deseas configurar tu conexión a Wi-fi ahora?"; 
       si="Sí"; 
      } 
      else 
      { 
       etiqueta="https://www.xxx.xx/launcher/xxx-xx/?language=en_US"; 
       mensaje="You have no connection. Do you want to configure your Wi-Fi connection?"; 
       si="Yes"; 
      } 
      dialogWifi(web); 
     } 
     //si hay un ID metido, entra directamente al mismo. Si no, va al launcher 
     if (Leer("ID").equals("vacío")==false) 
     { 
      //SEGUIDA DE LA EJECUCIÓN PREVIA 
      if ("ES".equals(Locale.getDefault().getCountry())) 
      { 
       //mensaje = "¿Quieres seguir la ejecución desde el punto en el que lo dejaste?"; 
       //si = "Sí"; 
       //leemos el fichero para saber si hay datos de ejecuciones previas 
       etiqueta="https://www.xxx.xx/xxx/"+Leer("ID")+"/?mode=autoplay&language=es_ES"; 

      } 
      else 
      { 
       // mensaje = "Do you want to continue the execution from the point you left it?"; 
       //si = "Yes"; 
       etiqueta="https://www.xxx.xx/player/"+Leer("ID")+"/?mode=autoplay&language=en_US"; 
      } 
      // dialReanudar(web); 
     } 

     web=(WebView)findViewById(R.id.webV); 
     GestionWeb.CrearWeb(etiqueta, web); 
     GestionWeb.Seguirweb(web); 

     //Para acelerar el webView 
     web.getSettings().setCacheMode(web.getSettings().LOAD_NO_CACHE); 
     web.getSettings().setRenderPriority(WebSettings.RenderPriority.HIGH); 
    } 
    public void BotonAjustes() 
    { 
     View.OnClickListener aj= new View.OnClickListener() 
     { 
      @Override 
      public void onClick(View view) 
      { 
       Intent intent= new Intent(MainActivity.this, Ajustes.class); 
       startActivity(intent); 
      } 
     }; 
     boton= (ImageButton) findViewById(R.id.imageButton7); 
     boton.setOnClickListener(aj); 
    } 
    /** 
    * Método para preguntarle al usuario si desea configurar el wi-fi o no. en caso afirmativo, se le redirecciona a ajustes 
    * @param view se necesitará para usar web 
    */ 
    public void dialogWifi(View view) 
    { 
     AlertDialog.Builder dial= new AlertDialog.Builder(this); 
     dial.setMessage(mensaje); 
     dial.setPositiveButton(si, new DialogInterface.OnClickListener() { 
      @Override 
      public void onClick(DialogInterface dialogInterface, int i) 
      { 
       //Abre la configuración de Wi-fi 
       startActivity(new Intent(Settings.ACTION_WIFI_SETTINGS)); 
       dialogInterface.cancel(); 
       web.reload(); 
      } 
     }); 
     dial.setNegativeButton("No", new DialogInterface.OnClickListener() { 
      @Override 
      public void onClick(DialogInterface dialogInterface, int i) 
      { 
       dialogInterface.cancel(); 
      } 
     }); 
     dial.create().show(); 
    } 

    public void dialReanudar(View view) 
    { 
     AlertDialog.Builder dial= new AlertDialog.Builder(this); 
     dial.setMessage(mensaje); 
     dial.setPositiveButton(si, new DialogInterface.OnClickListener() { 
      @Override 
      public void onClick(DialogInterface dialogInterface, int i) 
      { 
       //En este caso, etiqueta tendrá la web leída 
       etiqueta=Leer("enelace"); 
       GestionWeb.CrearWeb(etiqueta,web); 
       dialogInterface.cancel(); 
      } 
     }); 
     dial.setNegativeButton("No", new DialogInterface.OnClickListener() { 
      @Override 
      public void onClick(DialogInterface dialogInterface, int i) 
      { 
       dialogInterface.cancel(); 
      } 
     }); 
     dial.create().show(); 
    } 

    public static void Guardar(String guardado, String fichero) 
    { 
     SharedPreferences.Editor editor=datos.edit(); 
     editor.putString(fichero, guardado); 
     editor.commit(); 
    } 

    public static String Leer(String fichero) 
    { 
     String e=datos.getString(fichero, "vacío"); //(valor que queremos recoger, valor por defecto si no encuentra nada) 
     return e; 
    } 
} 

Answer 1

你應該叫requestWindowFeature(Window.FEATURE_NO_TITLE);前setContentView(R.layout.activity_main);

嘗試以下操作：

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    requestWindowFeature(Window.FEATURE_NO_TITLE); 
    setContentView(R.layout.activity_main); 
    ... 
}