onClickListener崩溃的应用程序和onOptionsItemSelected未按预期触发

Question

我正在尝试使用嵌入式数据库创建基本评级应用程序。不幸的是，每当我尝试将onClickListener编程到我的reportSomeoneButton时，应用程序崩溃或者事件没有被正确调用，按钮什么都不做。

预期的操作是，有人点击reportSomeoneButton，这会创建一个警告对话框，询问用户输入。用户输入注释，然后将信息存储在数据库中并填充下表。

我现在一直在努力奋斗好几个小时。教程没有达到我正在寻找的东西，有关stackoverflow的其他问题有助于学习不同的东西，但我似乎无法解决这个问题。我对使用Android Studio进行开发非常陌生，所以任何形式的帮助都会受到高度赞赏，无论是完美的解决方案，还是仅仅通过我的研究指向我正确的方向，我们都将不胜感激！

无论如何，这就是我所拥有的：

main activity.Java

import android.app.DatePickerDialog;
import android.content.ContentValues;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;

import java.util.Calendar;

import static android.provider.AlarmClock.EXTRA_MESSAGE;
public class MainActivity extends AppCompatActivity {

    public static final String EXTRA_MESSAGE = "Welcome!";

    //private Reports currentReport;
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void sendMessage(View view)
    {
        Intent intent = new Intent(this, DisplayMessageActivity.class);
        EditText editText = (EditText) findViewById(R.id.editText2);
        String message = editText.getText().toString();
        intent.putExtra(EXTRA_MESSAGE, message);
        startActivity(intent);
    }
}

activity_main.xml中

        <?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:minWidth="0dp"
    tools:context="com.example.feral.myapplication.MainActivity">

    <EditText
        android:id="@+id/editText2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="32dp"
        android:ems="10"
        android:hint="@string/edit_message"
        android:inputType="textPersonName"
        app:layout_constraintEnd_toStartOf="@+id/button2"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/imageView2" />

    <Button
        android:id="@+id/button2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="20dp"
        android:onClick="sendMessage"
        android:text="@string/button_send"
        app:layout_constraintBaseline_toBaselineOf="@+id/editText2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.5"
        app:layout_constraintStart_toEndOf="@+id/editText2"
        android:layout_marginLeft="20dp"
        android:layout_marginRight="16dp" />

    <ImageView
        android:id="@+id/imageView2"
        android:layout_width="wrap_content"
        android:layout_height="0dp"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:srcCompat="@drawable/honkhonklogo" />

</android.support.constraint.ConstraintLayout>

display message activity.Java

import android.app.AlertDialog;
import android.app.DatePickerDialog;
import android.content.ContentValues;
import android.content.DialogInterface;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.DatePicker;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.Calendar;

public class DisplayMessageActivity extends AppCompatActivity
{

    public String currentDate;
    private RatingDBHelper dbAssistant;
    private ListView listHandler;
    private ArrayAdapter<String> arrayHandler;
    private static final String TAG = "MainActivity";
    private TextView getCurrentDate;
    private DatePickerDialog.OnDateSetListener dateListener;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_display_message);
        Intent intent = getIntent();
        String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
        TextView textView = findViewById(R.id.textView);
        textView.setText("Welcome, " + message + "!");
        getCurrentDate = (TextView) findViewById(R.id.textView);
        getCurrentDate.setOnClickListener(new View.OnClickListener()
        {
            @Override
            public void onClick(View view)
            {
                Calendar calendar = Calendar.getInstance();
                int year = calendar.get(Calendar.YEAR);
                int month = calendar.get(Calendar.MONTH);
                int day = calendar.get(Calendar.DAY_OF_MONTH);
                //int date = calendar.get(Calendar.DAY_OF_WEEK);
                DatePickerDialog dialog = new DatePickerDialog(
                        DisplayMessageActivity.this,
                        android.R.style.Theme_DeviceDefault_Dialog_MinWidth,
                        dateListener,
                        year, month, day);
                dialog.getWindow().setBackgroundDrawable(new ColorDrawable(0xFFFF6666));
                dialog.show();
            }
        });
        dateListener = new DatePickerDialog.OnDateSetListener()
        {
            @Override
            public void onDateSet(DatePicker datePicker, int year, int month, int day)
            {
                month = month + 1;
                Log.d(TAG, "onDateSet: mm/dd/yyyy: " + month + "/" + day + "/" + year);

                String submittedDate = month + "/" + day + "/" + year;
                if (!(submittedDate != null && !submittedDate.isEmpty()))
                {
                    currentDate = submittedDate;
                }
                else
                {
                    currentDate = submittedDate;
                }
                getCurrentDate.setText(submittedDate);
            }
        };
          dbAssistant = new RatingDBHelper(this);
          listHandler = (ListView) findViewById(R.id.reportedRatings);
          refreshList();
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item)
    {
        switch (item.getItemId())
        {
            case R.id.reportSomeoneButton:
                final EditText reportInput = new EditText(this);
                AlertDialog dialog = new AlertDialog.Builder(this)
                        .setTitle("Report a Driver")
                        .setMessage("License Plate #: ")
                        .setView(reportInput)
                        .setPositiveButton("Submit", new DialogInterface.OnClickListener()
                        {
                            @Override
                            public void onClick(DialogInterface dialog, int i)
                            {
                                String licensePlate = String.valueOf(reportInput.getText());
                                SQLiteDatabase db = dbAssistant.getWritableDatabase();
                                ContentValues values = new ContentValues();
                                values.put(ReportDataSource.ReportSubmission.COL_TASK_TITLE, licensePlate + "\n" + currentDate);
                                db.insertWithOnConflict(ReportDataSource.ReportSubmission.TABLE,
                                        null, values, SQLiteDatabase.CONFLICT_REPLACE);
                                db.close();
                                refreshList();
                            }
                        })
                        .setNegativeButton("Cancel", null)
                        .create();
                dialog.show();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    private void refreshList()
    {
        ArrayList<String> reportList = new ArrayList<>();
        SQLiteDatabase db = dbAssistant.getReadableDatabase();
        Cursor cursor = db.query(ReportDataSource.ReportSubmission.TABLE,
                new String[] {ReportDataSource.ReportSubmission._ID, ReportDataSource.ReportSubmission.COL_TASK_TITLE},
                null, null, null, null,null);
        while (cursor.moveToNext())
        {
            int idx = cursor.getColumnIndex(ReportDataSource.ReportSubmission.COL_TASK_TITLE);
            reportList.add(cursor.getString(idx));
        }

        if(arrayHandler == null)
        {
            arrayHandler = new ArrayAdapter<>(this,
            R.layout.activity_display_message,
            R.id.textView,
            reportList);
            listHandler.setAdapter(arrayHandler);
        }
        else
        {
            arrayHandler.clear();
            arrayHandler.addAll(reportList);
            arrayHandler.notifyDataSetChanged();
        }
        cursor.close();
        db.close();
    }
}

activity_display_message.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.feral.myapplication.DisplayMessageActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:text="TextView"
        android:textSize="18sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <Button
        android:id="@+id/reportSomeoneButton"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:text="@string/reportSomeone"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/ratingBar" />

    <ImageView
        android:id="@+id/imageView3"
        android:layout_width="86dp"
        android:layout_height="55dp"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:cropToPadding="false"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView"
        app:srcCompat="@drawable/blankprofile" />

    <RatingBar
        android:id="@+id/ratingBar"
        style="@style/Widget.AppCompat.RatingBar"
        android:layout_width="240dp"
        android:layout_height="wrap_content"
        android:layout_marginEnd="16dp"
        android:layout_marginStart="16dp"
        android:layout_marginTop="16dp"
        android:clickable="true"
        android:isIndicator="false"
        android:stepSize="1"
        android:visibility="visible"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/imageView3" />


    <ListView
        android:id="@+id/reportedRatings"
        android:layout_width="0dp"
        android:layout_height="339dp"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginLeft="16dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="16dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.0"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/reportSomeoneButton" />

</android.support.constraint.ConstraintLayout>

我也有DBHelper，数据库源代码文件，但我不相信它们与这个问题有关。

再次，谢谢大家的帮助！

Answer 1

首先，在OnCreate（）中初始化reportsSomeButton。而不是在OnOptionsItemSelected（..）内部调用，在onCreate（）中尝试这个。

reportSomeoneButton.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

AlertDialog dialog = new AlertDialog.Builder(this)
                    .setTitle("Report a Driver")
                    .setMessage("License Plate #: ")
                    .setView(reportInput)
                    .setPositiveButton("Submit", new DialogInterface.OnClickListener()
                    {
                        @Override
                        public void onClick(DialogInterface dialog, int i)
                        {
                            String licensePlate = String.valueOf(reportInput.getText());
                            SQLiteDatabase db = dbAssistant.getWritableDatabase();
                            ContentValues values = new ContentValues();
                            values.put(ReportDataSource.ReportSubmission.COL_TASK_TITLE, licensePlate + "\n" + currentDate);
                            db.insertWithOnConflict(ReportDataSource.ReportSubmission.TABLE,
                                    null, values, SQLiteDatabase.CONFLICT_REPLACE);
                            db.close();
                            refreshList();
                        }
                    })
                    .setNegativeButton("Cancel", null)
                    .create();
            dialog.show();
            }



    });

希望这可以帮到你。