Question

我正在尝试将我的数据库的内容显示在ListView中。有一些错误（很明显），它在数据库中多次返回＃1行。

例如，如果有2行，则返回＃1行2次..如果我添加另一条记录，则返回＃1行3次。

这是我的 history.java

...
MySQLiteHelper db = new MySQLiteHelper(this);

Cursor cursor = db.getAllLogs();
Log.d("history.java", "finished Cursor cursor = db.getAllLogs();");
GasCursorAdapter adapter = new GasCursorAdapter(this, cursor, 0);
Log.d("history.java", "GasCursorAdapter adapter = new GasCursorAdapter(this, cursor, 0);");
listContent.setAdapter(adapter);
Log.d("history.java", "setAdapter(adapter);");

这是我的 MySQLiteHelper.java

...
public Cursor getAllLogs() {    
    List<String> List = new ArrayList<String>();

    String selectQuery = "SELECT * FROM " + TABLE_GASLOG;

    SQLiteDatabase db = this.getWritableDatabase();

    Cursor cursor = db.rawQuery(selectQuery, null);

    return cursor;
}

我猜这是getAllLogs()中我需要做的事情......但是我无法确定它。我曾尝试使用cursor.moveToFirst()和moveToNext，但这似乎会产生相同的结果......似乎知道有多条记录，但只是多次返回第一条记录！

非常感谢任何帮助！

编辑（附加信息）的 newRecord.java

public class newRecord extends Activity {

String fill;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.new_record);
    Typeface tf = Typeface.createFromAsset(getAssets(),"Roboto-Light.ttf");


    final MySQLiteHelper db = new MySQLiteHelper(this);

    final EditText pricePerGallon = (EditText) findViewById(R.id.pricePerGallon);
    final EditText gallons = (EditText) findViewById(R.id.gallons);
    final EditText odometer = (EditText) findViewById(R.id.odometer);
    final EditText today = (EditText) findViewById(R.id.date);
    final EditText comments = (EditText) findViewById(R.id.comments);
    final CheckBox notCompleteFill = (CheckBox) findViewById(R.id.completeFill);
    TextView save = (TextView) findViewById(R.id.save);
    TextView reset = (TextView) findViewById(R.id.reset);
    pricePerGallon.setTypeface(tf);
    gallons.setTypeface(tf);
    odometer.setTypeface(tf);
    today.setTypeface(tf);
    comments.setTypeface(tf);
    notCompleteFill.setTypeface(tf);
    save.setTypeface(tf);
    reset.setTypeface(tf);

    SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy");
    today.setText( sdf.format(new Date()));

    save.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v){
            String pricePerGallonString = pricePerGallon.getText().toString();
            final double pricePerGallonInt = Double.parseDouble(pricePerGallonString);
            String gallonsString = gallons.getText().toString();
            final double gallonsInt = Double.parseDouble(gallonsString);
            String odometerString = odometer.getText().toString();
            final double odometerInt = Double.parseDouble(odometerString);
            String todayString = today.getText().toString();
            String notCompleteFillString = notCompleteFill.getText().toString();
            String commentsString = comments.getText().toString();

            db.addGasLog(new gasLog(pricePerGallonInt, gallonsInt, odometerInt, todayString, fill, commentsString));
            Toast.makeText(getApplicationContext(), "Data Saved", Toast.LENGTH_LONG).show();
            Intent i = new Intent(newRecord.this, history.class);
            startActivity(i);
        }
    });

MySQLiteHelper.java

public void addGasLog(gasLog gasLog){
        // for logging
        Log.d("addGasLog", gasLog.toString());

        // 1. get reference to writable DB
        SQLiteDatabase db = this.getWritableDatabase();

        // 2. create ContentValues to add key "column"/value
        ContentValues values = new ContentValues();
        values.put(KEY_PRICE_PER_GALLON, gasLog.getPricePerGallon()); // get price
        values.put(KEY_GALLONS, gasLog.getGallons()); // get gallons
        values.put(KEY_ODOMETER, gasLog.getOdometer()); // get odometer
        values.put(KEY_DATE, gasLog.getDate()); // get date
        values.put(KEY_FILLED_OR_NOT, gasLog.getFilledOrNot()); // get filledOrNot
        values.put(KEY_COMMENTS, gasLog.getComments()); // get comments

        // 3. insert
        db.insert(TABLE_GASLOG, //table
                null, //nullColumnHack
                values); // key/value -> keys = column names/ values =

        // 4. Close
        db.close();
    }

EDIT2 的 GasCursorAdapter.java

import android.content.Context;
import android.content.Intent;
import android.database.Cursor;
import android.support.v4.widget.CursorAdapter;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.TextView;

public class GasCursorAdapter extends CursorAdapter {


    //private LayoutInflater mInflater = null;

    public GasCursorAdapter(Context context, Cursor c, int flags){
        super(context, c, flags);
        //mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        Log.d("inGasCursorAdapter", "GasCursorAdapter");
    }

    @Override
    public View newView(Context context, Cursor cursor, ViewGroup parent){
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        View retView = inflater.inflate(R.layout.card_background, parent, false);
        Log.d("inGasCursorAdapter", "newView");
        return retView;
        //return mInflater.inflate(R.layout.card_background,  parent, false);
    }

    @Override
    public void bindView(View v, Context context, Cursor cursor){
        /*
         * cardDate
         * cardGallons
         * cardPrice
         * cardMPG
         */

        TextView cardDate = (TextView) v.findViewById(R.id.cardDate);
        int date = cursor.getColumnIndexOrThrow(MySQLiteHelper.KEY_DATE);
        cardDate.setText(Integer.toString(date));

        TextView cardGallons = (TextView) v.findViewById(R.id.cardGallons);
        int gallons = cursor.getColumnIndexOrThrow(MySQLiteHelper.KEY_GALLONS);
        cardGallons.setText(Integer.toString(gallons) + "gal");

        TextView cardPrice = (TextView) v.findViewById(R.id.cardPrice);
        int price = cursor.getColumnIndexOrThrow(MySQLiteHelper.KEY_PRICE_PER_GALLON);
        cardPrice.setText("$" + Integer.toString(price));

        TextView cardMPG = (TextView) v.findViewById(R.id.cardMPG);
        int MPG = cursor.getColumnIndexOrThrow(MySQLiteHelper.KEY_ODOMETER);
        cardMPG.setText(Integer.toString(MPG));

        TextView cardDelete = (TextView) v.findViewById(R.id.cardDelete);
        cardDelete.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v){

            }
        });


    }

}

Answer 1

你的表有一个名为_id的列吗？如果不是，您可能需要选择单个列（无论如何应该选择而不是选择*），并将您的密钥主键别名为_id。

光标多次返回第1行

1 个答案: