android.support.v7.widget.Toolbar.getNavigationIconは、（）ここに...私は私のプロジェクトでいくつかのクラスを持っている...しかし、1つは私が一人で解決できないいくつかの問題を与える</p> <p>をヌル

Question

を返すです

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.setting); 
    toolbar = (android.support.v7.widget.Toolbar)findViewById(R.id.toolbar_002); 
    toolbar.setBackgroundColor(Common.color); 
    toolbar.setTitleTextColor(Common.compatible(Common.color, 0xFF000000) ? 0xFF000000 : 0xFFFFFFFF); 
    setSupportActionBar(toolbar); 
    getSupportActionBar().setDisplayShowTitleEnabled(true); 
    getSupportActionBar().setTitle("Settings"); 
    colorFilter = new PorterDuffColorFilter(Common.compatible(Common.color, 0xFF000000) ? 0xFF000000 : 0xFFFFFFFF, PorterDuff.Mode.MULTIPLY); 
    toolbar.getNavigationIcon().setColorFilter(colorFilter); 
    toolbar.setNavigationOnClickListener(new Button.OnClickListener() { 
     @Override 
     public void onClick(View v) { 
      main = new Intent(SettingActivity.this, MainActivity.class); 
      main.setFlags(Intent.FLAG_ACTIVITY_REORDER_TO_FRONT | Intent.FLAG_ACTIVITY_BROUGHT_TO_FRONT); 
      finish(); 
      startActivity(main); 
      overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out); 
     } 
    }); 
    getSupportActionBar().setDisplayHomeAsUpEnabled(true); 
    getSupportActionBar().setDisplayShowHomeEnabled(true); 
    getSupportActionBar().setDisplayShowTitleEnabled(true); 
    getSupportActionBar().setHomeButtonEnabled(true); 
    FragmentTransaction mFragmentTransaction = getFragmentManager().beginTransaction(); 
    mFragmentTransaction.replace(R.id.container, new PrefsFragment()); 
    mFragmentTransaction.commit(); 
} 

そして、私は活動を起動したとき、私はこれらのログを取得：

08-15 18:48:11.709 27903 27903 E AndroidRuntime        FATAL EXCEPTION: main 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        Process: fr.zwedge.kingwarrior, PID: 27903 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        java.lang.RuntimeException: Unable to start activity ComponentInfo{fr.zwedge.kingwarrior/fr.zwedge.kingwarrior.SettingActivity}: java.lang.NullPointerException 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2338) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2390) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.app.ActivityThread.access$800(ActivityThread.java:151) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1321) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.os.Handler.dispatchMessage(Handler.java:110) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.os.Looper.loop(Looper.java:193) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.app.ActivityThread.main(ActivityThread.java:5299) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at java.lang.reflect.Method.invokeNative(Native Method) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at java.lang.reflect.Method.invoke(Method.java:515) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:829) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:645) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at dalvik.system.NativeStart.main(Native Method) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        Caused by: java.lang.NullPointerException 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at fr.zwedge.kingwarrior.SettingActivity.onCreate(SettingActivity.java:113) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.app.Activity.performCreate(Activity.java:5264) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2302) 
08-15 18:48:11.709 27903 27903 E AndroidRuntime        ... 11 more 

...あなたは私がこの問題を解決することができますしてください？私に支障をきたすのonCreateメソッド ありがとう、Darkball60。

Answer 1

私はこの部分がgetNavigationIcon()を返すと思います。あなたがNullPointerExceptionを取得してはならないことをした後

toolbar.setNavigationIcon(ContextCompat.getDrawable(this, R.drawable.abc_ic_ab_back_mtrl_am_alpha)); 

：最初にこのようなナビゲーションアイコンを設定するようにしてください。