Android SQLiteDatabase返回null（空白）行

Question

一直在用我正在尝试构建的应用程序拉我的头发。我已经尝试了很多不同的东西，书籍，方式，YouTube教程，我已经失去了计数！我正在构建一个显示飞机图片的简单应用程序，然后用户点击将其添加到学习列表（通过使用烤面包而不是列表视图进行验证），然后单击另一个按钮查看此列表。

我有应用程序返回正确的行数，但它们都是空白的！从我读到的这意味着行是空的，但我不能为我的生活找出什么是错的！我会永远在谁的帮助下的债务:)

谢谢！下面的代码...

（数据库帮手/适配器）

package com.atcapp; 

import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.SQLException; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import android.util.Log; 

public class DatabaseAdapter { 

public static final String KEY_ROWID = "_id"; 
public static final String KEY_NAME = "name"; 
private static final String TAG = "DatabaseAdapter"; 

private static final String DATABASE_NAME = "LearntListdb"; 
private static final String DATABASE_TABLE = "AircraftTable"; 

private static final int DATABASE_VERSION = 1; 
private static final String DATABASE_CREATE = "create table AircraftTable (_id integer primary key   autoincrement, " 
     + "name text not null);"; 

private final Context context; 
private DatabaseHelper DBHelper; 
private SQLiteDatabase db; 

public DatabaseAdapter(Context ctx) { 
    this.context = ctx; 
    DBHelper = new DatabaseHelper(context); 
} 

private static class DatabaseHelper extends SQLiteOpenHelper { 

    public DatabaseHelper(Context context) { 
     super(context, DATABASE_NAME, null, DATABASE_VERSION); 
    } 

    @Override 
    public void onCreate(SQLiteDatabase db) { 
     db.execSQL(DATABASE_CREATE); 
    } 

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     Log.w(TAG, "Upgrading database from version " + oldVersion + " to " 
       + newVersion + "which will destroy all old data"); 
     db.execSQL("DROP TABLE IF EXISTS AircraftNames"); 
     onCreate(db); 
    } 
} 

// ---opens the database--- 
public DatabaseAdapter open() throws SQLException { 
    db = DBHelper.getWritableDatabase(); 
    return this; 
} 

// ---closes the database--- 
public void close() { 
    DBHelper.close(); 
} 

// ---insert an aircraft into the database--- 
public long insertAircraft(String name) { 
    ContentValues initialValues = new ContentValues(); 
    initialValues.put(KEY_NAME, name); 
    return db.insert(DATABASE_TABLE, null, initialValues); 
} 

// ---retrieves all the list--- 
public Cursor getAllAircraft() { 

    Cursor c = db.query(DATABASE_TABLE, new String[] {"_id", "name"}, null, null, null, null, null); 
    return c; 
} 

}

（活动目录）

package com.atcapp; 

import android.app.ListActivity; 
import android.database.Cursor; 
import android.os.Bundle; 
import android.widget.SimpleCursorAdapter; 

public class DataView extends ListActivity { 

private DatabaseAdapter mDbHelper; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 

    setContentView(R.layout.aircraftlist); 

    mDbHelper = new DatabaseAdapter(this); 

    mDbHelper.open(); 
    fillData(); 

} 

private void fillData(){ 
    Cursor c = mDbHelper.getAllAircraft(); 

    startManagingCursor(c); 



    String[] from = new String[] {DatabaseAdapter.KEY_ROWID, DatabaseAdapter.KEY_NAME}; 
    int[] to = new int[] {android.R.id.list}; 

    SimpleCursorAdapter myList = 
      new SimpleCursorAdapter(this, R.layout.list_row, c, from, to); 
    setListAdapter(myList); 

} 

}

Answer 1

您需要提供TextView的IDS在你的数组中。您需要将光标中的数据映射到适配器中的视图。

查看你的list_row布局，并从那里使用textview编号。