Java 我的应用程序崩溃，但没有显示错误

我正在开发一个向用户显示课程列表的应用程序 我的问题是，当我尝试运行我的应用程序时，它会崩溃而不显示错误

我想我的问题出在适配器上，但我不确定 这是我的MainActivity.java`

package com.example.android.mycoursesapp;

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.CheckBox;
import android.widget.ListView;

import com.google.firebase.database.ChildEventListener;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;

import java.util.ArrayList;
import java.util.List;

import static com.example.android.mycoursesapp.R.id.checkButton;


public class MainActivity extends AppCompatActivity {
    ListView mCourseListView;
    CheckBox mCheckBox;
    CourseAdapter courseAdapter;
    private ChildEventListener mchildEventListener; //to read from the database

    private FirebaseDatabase mfirebasedatabase; //to access the database
    private DatabaseReference mCoursesDatabaseReference; //references a specific part in the database

    private DatabaseReference mMessagesDatabaseReference; //class references a specific part of the database



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

        // Initialize course ListView and its adapter
        final List<Course> course = new ArrayList<>();
        courseAdapter = new CourseAdapter(this, R.layout.list_item, course);
        mCourseListView.setAdapter(courseAdapter);

        DatabaseReference mDatabase = FirebaseDatabase.getInstance().getReference();
        //get reference to child node
        mDatabase.child("courses").push().setValue("Physics");
        mDatabase.child("courses").push().setValue("Electronics");
        mDatabase.child("courses").push().setValue("System Analysis");
        mDatabase.child("courses").push().setValue("Artificial Intelligence");
        mDatabase.child("courses").push().setValue("English");
        mDatabase.child("courses").push().setValue("Economics");

        mchildEventListener=new ChildEventListener() {
            @Override
            public void onChildAdded(DataSnapshot dataSnapshot, String s) {
                Course course=dataSnapshot.getValue(Course.class);
                courseAdapter.add(course);
            }

            @Override
            public void onChildChanged(DataSnapshot dataSnapshot, String s) {}

            @Override
            public void onChildRemoved(DataSnapshot dataSnapshot) {}

            @Override
            public void onChildMoved(DataSnapshot dataSnapshot, String s) {}

            @Override
            public void onCancelled(DatabaseError databaseError) {}
        };
        mDatabase.addChildEventListener(mchildEventListener);

    /*add the Value event listener to update the data in real-time
        - displays the friendsDatabase items in a list*/
        //addValueEventListener(friendsDatabaseReference);

        /*Course course=new Course(listItemTextView.getText.
        mMessagesDatabaseReference.push().setValue(course);*/

        // Initialize references to views
        mCourseListView = (ListView) findViewById(R.id.courseListView);
        mCheckBox=(CheckBox) findViewById(checkButton);

        //Creating Adapter object for setting to list
        /*CourseAdapter adapter=new CourseAdapter(courseList,MainActivity.this);
        mCourseListView.setAdapter(adapter);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
                R.layout.list_item,
                listItemTextView,values);
        mCourseListView.setAdapter(adapter);*/




    }
}

这里是coursedapter.java

package com.example.android.mycoursesapp;

import android.app.Activity;
import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

import java.util.List;

/**
 */

public class CourseAdapter extends ArrayAdapter<Course>{
    //private Context mContext;
    //ArrayList<Course> mylist=new ArrayList<>();

    public CourseAdapter(Context context, int resource, List<Course> objects) {//resourse =list_item
        super(context,resource,objects);
    }

    //@Override public int getCount() {return mylist.size();}

    //@Override public Object getItem(int position) {return mylist.get(position).toString();}

    /*@Override
    public long getItemId(int position) {
        return position;
    }
    public void onItemSelected(int position) {}
    public class ViewHolder {
        public TextView coursetext;
        public CheckBox tick;}*/

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if (convertView == null) {
            convertView = ((Activity) getContext()).getLayoutInflater().inflate(R.layout.list_item, parent, false);
        }
        TextView courseTextView = (TextView) convertView.findViewById(R.id.listItemTextView);

        Course course=getItem(position);

        courseTextView.setText(course.getCourseName());

        /* TODO Auto-generated method stub
        ViewHolder view = null;
        LayoutInflater inflator = ((Activity) mContext).getLayoutInflater();
        if (view == null) {
            view = new ViewHolder();
            convertView = inflator.inflate(  R.layout.list_item, null);
            view.coursetext= (TextView) convertView.findViewById(R.id.listItemTextView);
            view.tick=(CheckBox)convertView.findViewById(R.id.checkButton);
            view.tick.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener(){
                @Override
                public void onCheckedChanged(CompoundButton button, boolean isChecked) {
                    int getPosition = (Integer) button.getTag(); // Here
                    // we get  the position that we have set for the checkbox using setTag.
                    mylist.get(getPosition).setChecked(button.isChecked()); // Set the value of checkbox to maintain its state.

                    if (isChecked) {
                        //do sometheing here
                    }
                    else
                    {
                        // code here
                    }
                }
            });
            convertView.setTag(view);
        } else {
            view = (ViewHolder) convertView.getTag();
        }
        view.tick.setTag(position);
        view.coursetext.setText("" + mylist.get(position).getCourseName());
        view.tick.setChecked(mylist.get(position).isChecked());*/
        return convertView;
    }
}

---

将下面两行移动到

setContentView（R.layout.activity_main）之后行

mCourseListView = (ListView) findViewById(R.id.courseListView);
        mCheckBox=(CheckBox) findViewById(checkButton);

没有日志？@KubaŁapuszyński我将编辑我的问题以显示我的日志可能与你告诉我的重复，我的应用程序仍然崩溃，但它显示了这个错误02-14 15:12:56.556 15365-15365/？E/HAL:load:id=gralloc！=hmi->id=gralloc 02-14 15:12:56.598 15365-15447/？E/HAL:load:id=gralloc！=hmi->id=gralloc 02-14 15:12:56.604 15365-15447/？E/HAL:load:id=gralloc！=hmi->id=gralloc
02-14 15:22:26.838 15829-15829/? I/art: Late-enabling -Xcheck:jni
02-14 15:22:26.932 15829-15829/com.example.android.mycoursesapp W/System: ClassLoader referenced unknown path: /data/app/com.example.android.mycoursesapp-2/lib/arm64
02-14 15:22:26.938 15829-15829/com.example.android.mycoursesapp I/InstantRun: Instant Run Runtime started. Android package is com.example.android.mycoursesapp, real application class is null.
02-14 15:22:27.460 15829-15829/com.example.android.mycoursesapp W/System: ClassLoader referenced unknown path: /data/app/com.example.android.mycoursesapp-2/lib/arm64
02-14 15:22:27.585 15829-15829/com.example.android.mycoursesapp I/FA: App measurement is starting up, version: 10084
02-14 15:22:27.586 15829-15829/com.example.android.mycoursesapp I/FA: To enable debug logging run: adb shell setprop log.tag.FA VERBOSE
02-14 15:22:27.604 15829-15829/com.example.android.mycoursesapp I/FA: To enable faster debug mode event logging run:
                                                                        adb shell setprop debug.firebase.analytics.app com.example.android.mycoursesapp
02-14 15:22:27.684 15829-15829/com.example.android.mycoursesapp I/HwCust: Constructor found for class android.app.HwCustAlarmManagerImpl
02-14 15:22:27.694 15829-15829/com.example.android.mycoursesapp I/FirebaseInitProvider: FirebaseApp initialization successful
02-14 15:22:27.887 15829-15829/com.example.android.mycoursesapp W/art: 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
02-14 15:22:28.183 15829-15829/com.example.android.mycoursesapp I/DynamiteModule: Considering local module com.google.android.gms.firebase_database:4 and remote module com.google.android.gms.firebase_database:5
02-14 15:22:28.183 15829-15829/com.example.android.mycoursesapp I/DynamiteModule: Selected remote version of com.google.android.gms.firebase_database, version >= 5
02-14 15:22:28.204 15829-15829/com.example.android.mycoursesapp W/System: ClassLoader referenced unknown path: /data/user/0/com.google.android.gms/app_chimera/m/00000007/n/arm64-v8a
02-14 15:22:28.273 15829-15829/com.example.android.mycoursesapp I/HwSecImmHelper: mSecurityInputMethodService is null
02-14 15:22:28.286 15829-15829/com.example.android.mycoursesapp E/HAL: load: id=gralloc != hmi->id=gralloc
02-14 15:22:28.301 15829-15906/com.example.android.mycoursesapp I/System: core_booster, getBoosterConfig = false
02-14 15:22:28.333 15829-15905/com.example.android.mycoursesapp E/HAL: load: id=gralloc != hmi->id=gralloc
02-14 15:22:28.333 15829-15905/com.example.android.mycoursesapp I/OpenGLRenderer: Initialized EGL, version 1.4
02-14 15:22:28.338 15829-15905/com.example.android.mycoursesapp W/OpenGLRenderer: load: so=/system/lib64/libhwuibp.so
                                                                                  dlopen failed: library "/system/lib64/libhwuibp.so" not found
02-14 15:22:28.338 15829-15905/com.example.android.mycoursesapp W/OpenGLRenderer: Initialize Binary Program Cache: Load Failed
02-14 15:22:28.338 15829-15905/com.example.android.mycoursesapp E/HAL: load: id=gralloc != hmi->id=gralloc
02-14 15:22:29.325 15829-15939/com.example.android.mycoursesapp I/System: core_booster, getBoosterConfig = false
02-14 15:22:30.704 15829-15829/com.example.android.mycoursesapp I/Process: Sending signal. PID: 15829 SIG: 9

mCourseListView = (ListView) findViewById(R.id.courseListView);
        mCheckBox=(CheckBox) findViewById(checkButton);