如何在 ListView 中使用 onItemClickListener 获取其他列

Posted 2023-04-19

【中文标题】如何在 ListView 中使用 onItemClickListener 获取其他列

【英文标题】：How to get other column with onItemClickListener in ListView

【发布时间】：2019-11-14 18:18:13

【问题描述】：

我正在处理一个购物清单，您可以在其中单击 ListView 中的项目并出现一个对话框。在那里您可以修改产品名称。它工作正常，但现在我正在尝试添加细节。 添加到数据库已经有效。它在第三列，但现在我无法使用 onItemClickListener 将其取出。 从第二列获取数据工作正常，因此产品与 ItemOnClick 一起工作正常。

我已经尝试了几个代码，但没有找到解决方案。

OnItemClick：

    lvProducts.setOnItemClickListener(new AdapterView.OnItemClickListener() 
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) 

            try 
                //DB*********************************
                String name = parent.getItemAtPosition(position).toString();

                Log.d(TAG, "onItemClick: You Clicked on " + name);
                Cursor data = myDB.getItemID(name);
                int itemID = -1;
                while (data.moveToNext())

                    itemID = data.getInt(0);


                
                if (itemID > -1)
                    Log.d(TAG, "onItemClick: The ID is " + itemID);
                    Intent editScreenIntent = new Intent();
                    editScreenIntent.putExtra("id",itemID);
                    editScreenIntent.putExtra("name",name);

                    selectedID = editScreenIntent.getIntExtra("id",-1);
                    selectedName = editScreenIntent.getStringExtra("name");
                






                showInputBox(arrayList.get(position), position);
             catch (Exception e) 
                Toast.makeText(ShoppingActivity.this, "Error#666", Toast.LENGTH_SHORT).show();
            
        
    );

数据库助手：

public class DatabaseHelper extends SQLiteOpenHelper 

    public static final String TABLE_NAME = "myList_data";
    public static final String COL1 = "ID";
    public static final String COL2 = "ITEM1";
    public static final String COL3 = "ITEM2";

    public DatabaseHelper(Context context)
        super(context, TABLE_NAME, null, 1);
    

    @Override
    public void onCreate(SQLiteDatabase db) 
        String createTable = "CREATE TABLE " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, " + COL2 + " TEXT, " + COL3 + " TEXT )";
        db.execSQL(createTable);
    
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) 
        db.execSQL("DROP TABLE IF EXISTS "+ TABLE_NAME);
        onCreate(db);
    

    public boolean addData(String item, String detail)
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL2,item);
        contentValues.put(COL3, detail);
        long result = db.insert(TABLE_NAME,null,contentValues);
        if (result == -1)
            return false;
        else 
            return true;
        
    







    public Cursor getData()
        SQLiteDatabase db = this.getWritableDatabase();
        String query = "SELECT * FROM " + TABLE_NAME;
        Cursor data = db.rawQuery(query, null);
        return data;
    
    public Cursor getItemID(String name)
        SQLiteDatabase db = this.getWritableDatabase();
        //String query = "SELECT "+ COL1 + " FROM " + TABLE_NAME + " WHERE " + COL2 + " = '" + name + "'";
        Cursor data = db.rawQuery("SELECT * FROM " + TABLE_NAME,null);
        //Cursor data = db.rawQuery(query, null);
        return data;
    




    /**
     * Updates the name field
     * @param newName
     * @param id
     * @param oldName
     */
    public void updateName(String newName,int id,String oldName)
        SQLiteDatabase db = this.getWritableDatabase();
        String query = "UPDATE " + TABLE_NAME + " SET " + COL2 + " = '" + newName + "' WHERE " + COL1 + " = '" + id + "'" + " AND " + COL2 + " = '" + oldName + "'";
        db.execSQL(query);
    
    public void deleteName(int id, String name)
        SQLiteDatabase db = this.getWritableDatabase();
        String query = "DELETE FROM " + TABLE_NAME + " WHERE " + COL1 + " = '" + id + "'" + " AND " + COL2 + " = '" + name + "'";
        db.execSQL(query);
    
    public void deleteAll()
        SQLiteDatabase db = this.getWritableDatabase();
        db.delete(TABLE_NAME,null,null);
        String query =("DELETE FROM " + TABLE_NAME);
        db.execSQL(query);

    

【参考方案1】：

试试：-

            int itemID = -1;
            String item3 = ""; //<<<<<<<<<< ADDED
            while (data.moveToNext())
                itemID = data.getInt(0);
                item3 = data.getString(data.getColumnIndex(DatabaseHelper.COL3)); //<<<<<<<<<< ADDED
            

注意使用 getColumnIndex 和列名更灵活，更不容易误算偏移量。您不妨考虑将itemID = data.getInt(0); 更改为itemID = data.getInt(data.getColumnIndex(DatabaseHelper.COL1));

您的 getItemId 方法将获取所有行，而不仅仅是具有名称的行。您可能希望更改为：-

public Cursor getItemID(String name)
    SQLiteDatabase db = this.getWritableDatabase();
    //String query = "SELECT "+ COL1 + " FROM " + TABLE_NAME + " WHERE " + COL2 + " = '" + name + "'";
    Cursor data = db.rawQuery("SELECT * FROM " + TABLE_NAME,null);
    //Cursor data = db.rawQuery(query, null);
    return data;

到：-

public Cursor getItemID(String name)
    SQLiteDatabase db = this.getWritableDatabase();
    return db.query(TABLE_NAME,null,COL2+"=?",new String[]name,null,null,null);

请注意，以上是原则代码。它尚未经过测试或运行，因此可能存在一些错误。

【讨论】：

非常感谢.. 有时解决方案很简单，但我对 SQLite 没有太多经验，所以这对我来说是全新的！