我的Android应用程序立即启动和停止

时间：2018-02-05 12:45:23

标签： android performance android-studio

我正在编写一个Android应用程序，但它不起作用。它会立即打开和停止。我真的不知道问题出在哪里以及为什么会发生。

MainActivity：

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        RecyclerView recyclerView=(RecyclerView) findViewById(R.id.rec);
        MyAdapter myAdapter=new MyAdapter(this,putName());
        recyclerView.setAdapter(myAdapter);
        LinearLayoutManager linearLayoutManager = new 
LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);
        recyclerView.setLayoutManager(linearLayoutManager);

    }

    public ArrayList<NameList> putName(){
        ArrayList<NameList> chart=new ArrayList<>();
        chart.add(new NameList("second one"));
        chart.add(new NameList("third one"));
        return chart;
    }
}

我有一个SharedPrefences课程：

public class MyShared extends Activity {

    private SharedPreferences sharedPreferences=getSharedPreferences("pref", 
Context.MODE_PRIVATE);

    public void Shared(int Int,Boolean boolea){
        SharedPreferences.Editor editor=sharedPreferences.edit();
        editor.putBoolean(Integer.toString(Int),boolea);
        editor.apply();
    }

    public Boolean getShared(int Int){
        Boolean boo=sharedPreferences.getBoolean(Integer.toString(Int),false);
        return boo;
   }

}

这是我的Namelist：

public class NameList{

    private String name;

    public NameList(String name){
        this.name=name;
    }

    public String getName() {
        return name;
    }
}

我有一个RecyclerView和两个按钮：一个用于在我的MyShared类中保存一个布尔值，另一个只是我的回收器的一个按钮。问题在哪里？

logcat的：

02-06 04:02:49.591: W/System(3573): ClassLoader referenced unknown path: /data/app/com.example.mehrad.first-2/lib/x86 02-06 04:02:49.679: W/art(3573): Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable 02-06 04:02:49.990: D/AndroidRuntime(3573): Shutting down VM 02-06 04:02:49.991: E/AndroidRuntime(3573): FATAL EXCEPTION: main 02-06 04:02:49.991: E/AndroidRuntime(3573): Process: com.example.mehrad.first, PID: 3573 02-06 04:02:49.991: E/AndroidRuntime(3573): java.lang.NullPointerException: Attempt to invoke interface method 'boolean android.content.SharedPreferences.getBoolean(java.lang.String, boolean)' on a null object reference 02-06 04:02:49.991: E/AndroidRuntime(3573): at com.example.mehrad.first.MyShared.getShared(MyShared.java:20) 02-06 04:02:49.991: E/AndroidRuntime(3573): at com.example.mehrad.first.MyAdapter.onBindViewHolder(MyAdapter.java:38) 02-06 04:02:49.991: E/AndroidRuntime(3573): at com.example.mehrad.first.MyAdapter.onBindViewHolder(MyAdapter.java:19) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:6310) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:6343) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:5289) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:5552) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5394) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:5390) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2149) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1533) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1496) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:593) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:3537) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.RecyclerView.onMeasure(RecyclerView.java:2979) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.View.measure(View.java:19857) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.constraint.ConstraintLayout.internalMeasureChildren(ConstraintLayout.java:383) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.constraint.ConstraintLayout.onMeasure(ConstraintLayout.java:431) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.View.measure(View.java:19857) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.ContentFrameLayout.onMeasure(ContentFrameLayout.java:139) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.View.measure(View.java:19857) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.support.v7.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:393) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.View.measure(View.java:19857) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.View.measure(View.java:19857) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1464) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.widget.LinearLayout.measureVertical(LinearLayout.java:758) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.widget.LinearLayout.onMeasure(LinearLayout.java:640) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.View.measure(View.java:19857) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:6083) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.widget.FrameLayout.onMeasure(FrameLayout.java:185) 02-06 04:02:49.991: E/AndroidRuntime(3573): at com.android.internal.policy.DecorView.onMeasure(DecorView.java:689) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.View.measure(View.java:19857) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2275) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1366) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1619) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1254) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6337) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:874) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.Choreographer.doCallbacks(Choreographer.java:686) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.Choreographer.doFrame(Choreographer.java:621) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:860) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.os.Handler.handleCallback(Handler.java:751) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.os.Handler.dispatchMessage(Handler.java:95) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.os.Looper.loop(Looper.java:154) 02-06 04:02:49.991: E/AndroidRuntime(3573): at android.app.ActivityThread.main(ActivityThread.java:6119) 02-06 04:02:49.991: E/AndroidRuntime(3573): at java.lang.reflect.Method.invoke(Native Method) 02-06 04:02:49.991: E/AndroidRuntime(3573): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 02-06 04:02:49.991: E/AndroidRuntime(3573): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

我编辑了我的logcat

1 个答案:

答案 0 :(得分：3)

您在创建活动之前调用了getSharedPreferences（）。在onCreate（）方法中进行调用。

这样的事情：

public class MyShared extends Activity {
    private SharedPreferences sharedPreferences;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        sharedPreferences = getSharedPreferences("pref", Context.MODE_PRIVATE);
    }
...
}
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