Android：SQLiteデータベース（複数の列）からListViewを読み込む

Question

私はAndroidでアプリケーションを開発しており、databseからlistviewにデータを渡して表示する際に問題があります。

は、ここですべてのメソッドと私のデータベースクラスである：

package com.example.admin.planesproject; 

import android.content.ContentValues; 
import android.content.Context; 
import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteOpenHelper; 
import com.example.admin.planesproject.TodoTask; 

public class PlanesDb { 

private static final int DB_VERSION = 1; 
private static final String DB_NAME = "database.db"; 
private static final String DB_TODO_TABLE = "PlanesDb"; 

//columns 

public static final String KEY_ID = "_id"; 
public static final String ID_OPTIONS = "INTEGER PRIMARY KEY AUTOINCREMENT"; 
public static final int ID_COLUMN = 0; 

public static final String KEY_DATE = "date"; 
public static final String DATE_OPTIONS = "TEXT NOT NULL"; 
public static final int DATE_COLUMN = 1; 

public static final String KEY_DIRECTION = "direction"; 
public static final String DIRECTION_OPTIONS = "TEXT NOT NULL"; 
public static final int DIRECTION_COLUMN = 2; 

public static final String KEY_MODEL = "model"; 
public static final String MODEL_OPTIONS = "TEXT"; 
public static final int MODEL_COLUMN = 3; 

public static final String KEY_AIRLINES = "airlines"; 
public static final String AIRLINES_OPTIONS = "TEXT"; 
public static final int AIRLINES_COLUMN = 4; 

public static final String KEY_FROM = "from"; 
public static final String FROM_OPTIONS = "TEXT"; 
public static final int FROM_COLUMN = 5; 

public static final String KEY_TO = "to"; 
public static final String TO_OPTIONS = "TEXT"; 
public static final int TO_COLUMN = 6; 

private static final String DB_CREATE_TODO_TABLE = 
     "CREATE TABLE " + DB_TODO_TABLE + "(" + 
       KEY_ID + " " + ID_OPTIONS + ", " + 
       KEY_DATE + " " + DATE_OPTIONS + ", " + 
       KEY_DIRECTION + " " + DIRECTION_OPTIONS + ", " + 
       KEY_MODEL + " " + MODEL_OPTIONS + ", " + 
       KEY_AIRLINES + " " + AIRLINES_OPTIONS + ", " + 
       KEY_FROM + " " + FROM_OPTIONS + ", " + 
       KEY_TO + " " + TO_OPTIONS + ");"; 

private static final String DROP_TODO_TABLE = 
     "DROP TABLE IF EXISTS " + DB_TODO_TABLE; 

private SQLiteDatabase db; 
private Context context; 
private DatabaseHelper dbHelper; 

private static class DatabaseHelper extends SQLiteOpenHelper { 
    public DatabaseHelper(Context context, String name, 
          SQLiteDatabase.CursorFactory factory, int version) { 
     super(context, name, factory, version); 
    } 

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

    @Override 
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) { 
     db.execSQL(DROP_TODO_TABLE); 
     onCreate(db); 
    } 
} 

public PlanesDb(Context context) { 
    this.context = context; 
} 

public PlanesDb open(){ 
    dbHelper = new DatabaseHelper(context, DB_NAME, null, DB_VERSION); 
    db = dbHelper.getWritableDatabase(); 
    return this; 
} 

public void close() { 
    dbHelper.close(); 
} 

public long insertTodo(String date, String direction, String model, String airlines, String from, String to) { 
    ContentValues newTodoValues = new ContentValues(); 
    newTodoValues.put(KEY_DATE, date); 
    newTodoValues.put(KEY_DIRECTION, direction); 
    newTodoValues.put(KEY_MODEL, model); 
    newTodoValues.put(KEY_AIRLINES, airlines); 
    newTodoValues.put(KEY_FROM, from); 
    newTodoValues.put(KEY_TO, to); 
    return db.insert(DB_TODO_TABLE, null, newTodoValues); 
} 

public boolean updateTodo(TodoTask task) { 
    long id = task.getId(); 
    String date = task.getDate(); 
    String direction = task.getDirection(); 
    String model = task.getModel(); 
    String airlines = task.getAirlines(); 
    String from = task.getFrom(); 
    String to = task.getTo(); 
    return updateTodo(id, date, direction, model, airlines, from, to); 
} 

public boolean updateTodo(long id, String date, String direction, String model, String airlines, String from, String to) { 
    String where = KEY_ID + "=" + id; 
    ContentValues updateTodoValues = new ContentValues(); 
    updateTodoValues.put(KEY_DATE, date); 
    updateTodoValues.put(KEY_DIRECTION, direction); 
    updateTodoValues.put(KEY_MODEL, model); 
    updateTodoValues.put(KEY_AIRLINES, airlines); 
    updateTodoValues.put(KEY_FROM, from); 
    updateTodoValues.put(KEY_TO, to); 
    return db.update(DB_TODO_TABLE, updateTodoValues, where, null) > 0; 
} 

public boolean deleteTodo(long id){ 
    String where = KEY_ID + "=" + id; 
    return db.delete(DB_TODO_TABLE, where, null) > 0; 
} 

public Cursor getAllTodos() { 
    String[] columns = {KEY_ID, KEY_DATE, KEY_DIRECTION, KEY_MODEL, KEY_AIRLINES, KEY_FROM, KEY_TO}; 
    return db.query(DB_TODO_TABLE, columns, null, null, null, null, null); 
} 
} 

私は私のテーブルからすべてを示すリストビューを持っているしたいのですが、私はそれを行う方法を把握することはできません。チュートリアルでは、ほとんどの場合、1つの行データベースを操作する方法しか示されていないため、あまり役に立ちません。すべてのgetterとsetterを持つ

私のToDoタスク：

public class TodoTask { 
private long id; 
private String date; 
private String direction; 
private String model; 
private String airlines; 
private String from; 
private String to; 

public TodoTask(long id, String date, String direction, String model, String airlines, String from, String to) { 
    this.id = id; 
    this.date = date; 
    this.direction = direction; 
    this.model = model; 
    this.airlines = airlines; 
    this.from = from; 
    this.to = to; 
} 

public long getId() { 
    return id; 
} 

public void setId(long id) { 
    this.id = id; 
} 

public String getDate(){ 
    return date; 
} 

public void setDate(String date){ 
    this.date = date; 
} 

public String getDirection(){ 
    return direction; 
} 

public void setDirection(String direction){ 
    this.direction = direction; 
} 

public String getModel(){ 
    return model; 
} 

public void setModel(String model){ 
    this.model = model; 
} 

public String getAirlines(){ 
    return airlines; 
} 

public void setAirlines(String airlines){ 
    this.airlines = airlines; 
} 

public String getFrom(){ 
    return from; 
} 

public void setFrom(String from){ 
    this.from = from; 
} 

public String getTo(){ 
    return to; 
} 

public void setTo(String to){ 
    this.to = to; 
} 

} 

そして最後に私の活動。これは、配列からlistviewを取り込む方法です。私のデータベースに似たものが必要です。

import android.app.Activity; 
import android.content.res.Resources; 
import android.os.Bundle; 
import android.widget.ArrayAdapter; 
import android.widget.ListView; 

public class DatabaseCheck extends Activity { 

    private ListView lvPlanes; 
    private String[] planes; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_database_check); 
     lvPlanes = (ListView) findViewById(R.id.list_all); 
     initResources(); 
     initListView(); 
    } 

    private void initResources() { 
     Resources res = getResources(); 
     planes = res.getStringArray(R.array.listofplanes); 
    } 

    private void initListView() { 
     lvPlanes.setAdapter(new ArrayAdapter<String>(
       getBaseContext(), 
       android.R.layout.simple_list_item_1, 
       planes)); 
    } 
} 

DBを開いてリストを作成し、DBを閉じる必要があります。私はカスタムアダプターを構築すべきだと理解していますが、私は何をしたいのか分かりません。私は何かをやってみたが、すべての試みはアプリのクラッシュで終わった。誰でも助けてくれますか？どんな提案もありがとうございます、事前にありがとうございます。

Answer 1

CursorAdapter定義し、これを試してください：あなたのinitListViewにリストビューにアダプタを設定し、その後

public class yourCursorAdapter extends CursorAdapter { 
    public yourCursorAdapter(Context context, Cursor cursor) { 
     super(context, cursor, 0); 
    } 

    @Override 
    public View newView(Context context, Cursor cursor, ViewGroup parent) { 
     return LayoutInflater.from(context).inflate(R.layout.item_todo, parent, false); 
    } 

    @Override 
    public void bindView(View view, Context context, Cursor cursor) { 

     // Find all fields to populate in inflated template 
     // Example 
     TextView tvDate = (TextView) view.findViewById(R.id.tvDate); 

     // Extract all needed properties from cursor 
     // Example 
     String date = cursor.getString(cursor.getColumnIndexOrThrow("date")); 

     // Populate all the required fields with extracted properties 
     // Example 
     tvDate.setText(date); 

    } 
} 

を：

private void initListView() { 
    DatabaseHelper handler = new DatabaseHelper(this); 
    SQLiteDatabase db = handler.getWritableDatabase(); 
    Cursor cursor = db.rawQuery(YOUR_SQL_QUERY, null); 
    yourCursorAdapter adapter = new yourCursorAdapter(this, cursor); 
    lvPlanes.setAdapter(adapter); 
} 

はそれがCursorAdapter` `で