從數據庫中刪除項目 - Android Studio中的ListView

Question

我在我的程序中有一個列表視圖，我有三個按鈕。

如下圖所示：

我想，當我上的刪除按鈕單擊可從列表視圖和數據庫中刪除的任何項目。

我試圖刪除，但被清除了所有項目。

請幫助me.thanks

我的數據庫幫手：

public class DatabaseHelper1 extends SQLiteOpenHelper { 

public static final String DATABASE_NAME = "mylist.db"; 
public static final String TABLE_NAME = "mylist_data"; 
public static final String COL_1 = "ID"; 
public static final String COL_2 = "billID"; 
public static final String COL_3 = "payID"; 
public static final String COL_4 = "txtLOCATION"; 
public static final String COL_5 = "txtTYPE"; 


public DatabaseHelper1(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,\n" + 
      " billID INTEGER, payID INTEGER, txtLOCATION TEXT, txtTYPE TEXT)"); 


} 

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

public boolean addData(String billid, String payid, String txtlocation, 
         String txttype) { 

    SQLiteDatabase db = this.getWritableDatabase(); 
    ContentValues contentValues = new ContentValues(); 
    contentValues.put(COL_2, billid); 
    contentValues.put(COL_3, payid); 
    contentValues.put(COL_4, txtlocation); 
    contentValues.put(COL_5, txttype); 

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

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

public Cursor getListContents() { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    Cursor data = db.rawQuery("SELECT * FROM " + TABLE_NAME, null); 
    return data; 
} 
    public void deleteAll() 
    { 
     SQLiteDatabase db = this.getWritableDatabase(); 
     db.delete(DatabaseHelper1.TABLE_NAME, null, null); 
    } 
} 

我的目錄適配器：

public class FourColumn_ListAdapter extends ArrayAdapter<User> { 

DatabaseHelper1 myDB; 
private LayoutInflater mInflater; 
private ArrayList<User> users; 
private int mViewResourceId; 


public FourColumn_ListAdapter(Context context, int textViewResourcesId, ArrayList<User> users){ 
    super(context,textViewResourcesId, users); 
    this.users = users; 
    mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    mViewResourceId = textViewResourcesId; 
} 

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

    convertView = mInflater.inflate(mViewResourceId, null); 

    final User user = users.get(position); 

    if (user != null){ 
     TextView billId = (TextView) convertView.findViewById(R.id.bilid); 
     TextView payId = (TextView) convertView.findViewById(R.id.pyid); 
     TextView location = (TextView) convertView.findViewById(R.id.lc); 
     TextView types = (TextView) convertView.findViewById(R.id.noe); 

     if(billId != null){ 
      billId.setText((user.getBillID())); 
     } 
     if(payId != null){ 
      payId.setText((user.getPayID())); 
     } 
     if(location != null){ 
      location.setText((user.getLocation())); 
     } 
     if(types != null){ 
      types.setText((user.getTypes())); 
     } 
     final Button button = (Button)convertView.findViewById(R.id.btnDelete); 
     button.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 

       new AlertDialog.Builder(getContext()) 
         .setTitle("حذف قبض") 
         .setMessage("آیا از حذف این قبض اطمینان دارید؟ ") 
         .setPositiveButton("بله", 
           new DialogInterface.OnClickListener() { 

            public void onClick(DialogInterface dialog, int id) { 
             myDB = new DatabaseHelper1(getContext()); 
             myDB.deleteAll(); 
             users.remove(position); 
             notifyDataSetChanged(); 


            } 
           }) 
         .setNegativeButton("بیخیال", new DialogInterface.OnClickListener() { 

          public void onClick(DialogInterface dialog, int id) { 

           dialog.cancel(); 
          } 
         }).show(); 


     } 
     }); 

    } 
    return convertView; 
} 

Answer 1

當我刪除按鈕單擊可從刪除任何項目列表 視圖和數據庫

創建DELETE方法

public void deleteItem(String getID) { 
     SQLiteDatabase db = this.getWritableDatabase(); 
     db.execSQL("DELETE from mylist_data WHERE billID='"+getID+"'"); 
    } 

然後

public void onClick(DialogInterface dialog, int id) 
            { 
            myDB = new DatabaseHelper1(getContext()); 
            myDB.deleteItem(user.getBillID()); 
            users.remove(position); 
            notifyDataSetChanged(); 

            }