如何从自定义 ListView() 中获取数据库 ID

Question

我想在单击列表项时获取数据库行 ID。在我的自定义列表视图适配器中，我使用了 onClickListener，我想从中获取 ID。请任何人帮助我....

这是我的自定义列表视图适配器

public class Quiz_list_adapter extends BaseAdapter{


Context context;
ArrayList<String> aL1 = new ArrayList<>();
ArrayList<String> aL2 = new ArrayList<>();
ArrayList<String> aL3 = new ArrayList<>();
ArrayList<String> aL4 = new ArrayList<>();
ArrayList<String> aL5 = new ArrayList<>();
ArrayList<String> aL6 = new ArrayList<>();
ArrayList<String> aL7 = new ArrayList<>();

QuizDatabaseHelper myDb;



private static LayoutInflater  inflater = null;

public Quiz_list_adapter(QuizReminder mainAct, ArrayList<String> a1,ArrayList<String> a2,ArrayList<String> a3,
                         ArrayList<String> a4,ArrayList<String> a5,ArrayList<String> a6,ArrayList<String> a7){
    aL1 = a1;
    aL2 = a2;
    aL3 = a3;
    aL4 = a4;
    aL5 = a5;
    aL6 = a6;
    aL7 = a7;

    context = mainAct;

    inflater = (LayoutInflater)  context.getSystemService(context.LAYOUT_INFLATER_SERVICE);

    myDb = new QuizDatabaseHelper(context);
}


@Override
public int getCount() {
    return aL1.size();
}

@Override
public Object getItem(int position) {

    return position;
}

@Override
public long getItemId(int position) {
    return position;
}

public class MyHolder{
    TextView tv1, tv2, tv3, tv4, tv5, tv6, tv7;

}

@Override
public View getView(final int position, View convertView, final ViewGroup parent) {

    final MyHolder myHolder = new MyHolder();
    final View myView;

    myView = inflater.inflate(R.layout.custom_quiz_layout, null);

    myHolder.tv1 = (TextView) myView.findViewById(R.id.title);
    myHolder.tv2 = (TextView) myView.findViewById(R.id.details);
    myHolder.tv3 = (TextView) myView.findViewById(R.id.hour);
    myHolder.tv4 = (TextView) myView.findViewById(R.id.minute);
    myHolder.tv5 = (TextView) myView.findViewById(R.id.day);
    myHolder.tv6 = (TextView) myView.findViewById(R.id.month);
    myHolder.tv7 = (TextView) myView.findViewById(R.id.year);

    myHolder.tv1.setText(aL1.get(position));
    myHolder.tv2.setText(aL2.get(position));
    myHolder.tv3.setText(aL3.get(position));
    myHolder.tv4.setText(aL4.get(position));
    myHolder.tv5.setText(aL7.get(position));
    myHolder.tv6.setText(aL3.get(position));
    myHolder.tv7.setText(aL5.get(position));





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


            Integer deletedRow = myDb.deleteData(String.valueOf(position));

            aL1.remove(position);
            notifyDataSetChanged();

            if(deletedRow >0){
                Toast.makeText(context, "Data Deleted !", Toast.LENGTH_LONG).show();
            }
            else{
                Toast.makeText(context,"Data not Deleted !", Toast.LENGTH_LONG).show();
            }
        }
    });


    return myView;
}
}

这是我的数据库助手类

public class QuizDatabaseHelper extends SQLiteOpenHelper{

public static final String DATABASE_NAME = "quiz.db";
public static final String TABLE_NAME = "quiz_table";
public static final String COL_1 = "ID";
public static final String COL_2 = "TITLE";
public static final String COL_3 = "DETAILS";
public static final String COL_4 = "HOUR";
public static final String COL_5 = "MINUTE";
public static final String COL_6 = "YEAR";
public static final String COL_7 = "MONTH";
public static final String COL_8 = "DAY";

public QuizDatabaseHelper(Context context) {
    super(context, DATABASE_NAME, null, 1);
}

@Override
public void onCreate(SQLiteDatabase db) {
    db.execSQL("CREATE TABLE " + TABLE_NAME +"(ID INTEGER PRIMARY KEY AUTOINCREMENT, " +
            "TITLE TEXT, DETAILS TEXT, HOUR TEXT, MINUTE TEXT, YEAR TEXT, MONTH TEXT, DAY TEXT)" );
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
    onCreate(db);
}

public boolean insertData(String title, String details, String hour, String minute,
                          String year, String month, String day){

    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();

    contentValues.put(COL_2, title);
    contentValues.put(COL_3, details);
    contentValues.put(COL_4, hour);
    contentValues.put(COL_5, minute);
    contentValues.put(COL_6, year);
    contentValues.put(COL_7, month);
    contentValues.put(COL_8, day);


    long result = db.insert(TABLE_NAME, null, contentValues);

    if(result == -1){
        return  false;
    }
    else{
        return true;
    }
}


public Cursor getAllData(){

    SQLiteDatabase db = this.getWritableDatabase();
    Cursor result = db.rawQuery("SELECT * FROM " +TABLE_NAME, null);

    return result;
}


public boolean updateData(String id,  String title, String details, String hour,
                          String minute, String year, String month, String day){
    SQLiteDatabase db = this.getWritableDatabase();
    ContentValues contentValues = new ContentValues();

    contentValues.put(COL_1, id);
    contentValues.put(COL_2, title);
    contentValues.put(COL_3, details);
    contentValues.put(COL_4, hour);
    contentValues.put(COL_5, minute);
    contentValues.put(COL_6, year);
    contentValues.put(COL_7, month);
    contentValues.put(COL_8, day);

    db.update(TABLE_NAME,contentValues, "ID = ?", new String[] { id });

    return true;

}

public Integer deleteData(String id) {
    SQLiteDatabase db = this.getWritableDatabase();

    return db.delete(TABLE_NAME,"ID = ?",new String[] {id});

}

}

Answer 1

在您的 QuizDataBaseHelper 中添加此方法

public Integer getId(int position){
    int id = 0;
    Cursor cur = db.rawQuery("SELECT * FROM " +TABLE_NAME, null);
        cur.moveToPosition(position);
        id = cur.getInteger(1);
        cur.close();
   return id;
}

在您的项目点击时调用它；我没有执行，但这是获取数据的方式，如果有任何问题，请在 cmets 中提及。

Answer 2

使用 setOnItemClickListener 而不是在 adpater 之外的 onClickListener ，即在相关活动中。然后提供 id（假设是光标适配器）。

yourListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view,
                                    int position,
                                    long id) {
                ......
            }
        });

LongClick 的类似。