android - 在 Android 中删除 ListiView 和 SQLite 行

Question

我正在使用这个库在 Android Studio 中开发一个应用程序：com.daimajia.swipelayout:library:1.2.0@aar。我的应用程序用户使用具有以下类的 SQLite 数据库：

BDSQLiteHelper.java

public class BDSQLiteHelper extends SQLiteOpenHelper {

    private static final int DATABASE_VERSION = 1;
    private static final String DATABASE_NAME = "ExtraOficial";
    private static final String TABELA_VAZAMENTOS = "VazamentosToSQL";

    private static final String vazID = "VazID";
    private static final String nomeServico = "nomeServico";
    private static final String[] VAZ_COLUNAS = {vazID, nomeServico};

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

@Override
    public void onCreate(SQLiteDatabase db) {
String CREATE_VAZAMENTOTABLE = "CREATE TABLE VazamentosToSQL ("+
                "vazID          INTEGER PRIMARY KEY AUTOINCREMENT,"+
                "nomeServico)";
        db.execSQL(CREATE_VAZAMENTOTABLE);
 }

@Override
    public void onUpgrade(SQLiteDatabase db, int i, int i1) {
        db.execSQL("DROP TABLE IF EXISTS VazamentosToSQL");
        this.onCreate(db);

    }
public void addVazamentos(VazamentosToSQL VazamentosToSQL) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues values = new ContentValues();
        values.put(nomeServico, VazamentosToSQL.getNomeServico());
        db.insert(TABELA_VAZAMENTOS, null, values);
        db.close();
    }
public VazamentosToSQL getVazamentos (int vazID) {
        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.query(TABELA_VAZAMENTOS,
                VAZ_COLUNAS,
                " vazID = ?",
                new String[] {String.valueOf(vazID)},
                null,
                null,
                null,
                null);
        if (cursor == null) {
            return null;
        } else {
            cursor.moveToFirst();
            VazamentosToSQL VazamentosToSQL = cursorTovazamentos(cursor);
            return VazamentosToSQL;
        }
    }


private VazamentosToSQL cursorTovazamentos(Cursor cursor) {
        VazamentosToSQL VazamentosToSQL = new VazamentosToSQL();
        VazamentosToSQL.setVazID(Integer.parseInt(cursor.getString(0)));
        VazamentosToSQL.setNomeServico(cursor.getString(1));
        return VazamentosToSQL;
    }


public ArrayList<VazamentosToSQL> getAllVazamentos() {
        ArrayList<VazamentosToSQL> listaVazamentos = new ArrayList<VazamentosToSQL>();
        String query = "SELECT * FROM " + TABELA_VAZAMENTOS + " ORDER BY "+ vazID + " DESC";

        SQLiteDatabase db = this.getReadableDatabase();
        Cursor cursor = db.rawQuery(query, null);

        if (cursor.moveToFirst()) {
            do {
                VazamentosToSQL VazamentosToSQL = cursorTovazamentos(cursor);
                listaVazamentos.add(VazamentosToSQL);
            } while (cursor.moveToNext());

        }
        return listaVazamentos;
    }

[...]

public int deleteVazamentos(VazamentosToSQL VazamentosToSQL) {
        SQLiteDatabase db = this.getWritableDatabase();

        int i = db.delete(TABELA_VAZAMENTOS,
                vazID+" =?",
                new String[] { String.valueOf(VazamentosToSQL.getVazID())});
        db.close();
        return i;
    }

VazamentosToSQL.java

public class VazamentosToSQL {
    private int vazID;
    private String nomeServico;
  public int getVazID() { return vazID; }
    public void setVazID(int vazID) {
        this.vazID = vazID;
    }


    public String getNomeServico() { return nomeServico; }
    public void setNomeServico(String nomeServico) { this.nomeServico = nomeServico; }

}

ListViewActivity.java：

[...]
//variables
private BDSQLiteHelper bd;
ArrayList<VazamentosToSQL> listaVazamentos;
SwipeLayout swipeLayout;
private final static String TAG = ListViewActivity.class.getSimpleName();
vazamentosAdapter adapter;
ListView lista;
[...]
@Override
    protected void onCreate(Bundle savedInstanceState) 
{super.onCreate(savedInstanceState);

[...]

 bd = new BDSQLiteHelper(this);
        lista = (ListView) findViewById(R.id.lvdenuncias);
        listaVazamentos = bd.getAllVazamentos();
        setListViewHeader();
        setListViewAdapter();

lista.setOnItemClickListener(new AdapterView.OnItemClickListener() { //aqui é o vazamentosAdapter
            @Override
            public void onItemClick(AdapterView<?> parent, View view,
                                    int position, long id) {
                Intent intent = new Intent(ExibeVazamentosActivity.this, DetalhesVazamentosActivity.class);
                intent.putExtra("vazID", listaVazamentos.get(position).getVazID());
                startActivity(intent);

            }
        });
@Override
    protected void onStart() {
        super.onStart();
        updateAdapter(); //Refresh ListView items

    }
private void setListViewHeader() {
        LayoutInflater inflater = getLayoutInflater();
        View header = inflater.inflate(R.layout.header_listview, lista, false);
        totalClassmates = (TextView) header.findViewById(R.id.total);
        swipeLayout = (SwipeLayout)header.findViewById(R.id.swipe_layout);
        setSwipeViewFeatures();
        //UNNECESSARY for me: lista.addHeaderView(header);
    }
private void setSwipeViewFeatures() {
        swipeLayout.setShowMode(SwipeLayout.ShowMode.PullOut);

        //add drag edge.(If the BottomView has 'layout_gravity' attribute, this line is unnecessary)
        swipeLayout.addDrag(SwipeLayout.DragEdge.Left, findViewById(R.id.bottom_wrapper));

        swipeLayout.addSwipeListener(new SwipeLayout.SwipeListener() {
            @Override
            public void onClose(SwipeLayout layout) {
                Log.i(TAG, "onClose");
            }

            @Override
            public void onUpdate(SwipeLayout layout, int leftOffset, int topOffset) {
                Log.i(TAG, "on swiping");
            }

            @Override
            public void onStartOpen(SwipeLayout layout) {
                Log.i(TAG, "on start open");
            }

            @Override
            public void onOpen(SwipeLayout layout) {
                Log.i(TAG, "the BottomView totally show");
            }

            @Override
            public void onStartClose(SwipeLayout layout) {
                Log.i(TAG, "the BottomView totally close");
            }

            @Override
            public void onHandRelease(SwipeLayout layout, float xvel, float yvel) {
                //when user's hand released.
            }
        });
    }

private void setListViewAdapter() {
          adapter = new vazamentosAdapter(this, listaVazamentos);
          lista.setAdapter(adapter);
    }


    public void updateAdapter() {
        listaVazamentos.clear();
        listaVazamentos.addAll(bd.getAllVazamentos());
        adapter.notifyDataSetChanged(); //update adapter
        lista.invalidateViews();
        lista.refreshDrawableState();
    }
}

vazamentosAdapter.java：

public class vazamentosAdapter extends ArrayAdapter<VazamentosToSQL> {
    private final Context context;
    private final ArrayList<VazamentosToSQL> elementos;
    File imgFile;
    private Bitmap bitmap;
    private ExifInterface exifObject;
    private ExibeVazamentosActivity activity;
    int vazID;
    private SQLiteDatabase bd;

public vazamentosAdapter(Context context, ArrayList<VazamentosToSQL> elementos) {
        super(context, R.layout.linha, elementos);
        this.context = context;
        this.elementos = elementos;

    }
@Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder holder;

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

        if (convertView == null) {
            // inflate UI from XML file
            convertView = inflater.inflate(R.layout.linha, parent, false);
            // get all UI view
            holder = new ViewHolder(convertView);
            // set tag for holder
            convertView.setTag(holder);
        }else {
            // if holder created, get tag from view
            holder = (ViewHolder) convertView.getTag();
        }
[...]
editText.setText(elementos.get(position).getVaznomeServico());

 holder.btnEdit.setOnClickListener(onEditListener(position, holder));
        holder.btnDelete.setOnClickListener(onDeleteListener(position, holder));

        return convertView;
    }

private View.OnClickListener onDeleteListener(final int position, final ViewHolder holder) {
        return new View.OnClickListener() {
            @Override
            public void onClick(View v) {

            /**--------------Tried it, not working =( ---------------*/
                elementos.get(position).getVazID(); 
               //listaVazamentos.remove(position); 
                //activity.listaVazamentos.remove(position); 
                //bd = context.openOrCreateDatabase("DesoExtraOficial", Activity.MODE_PRIVATE, null);
                //bd.execSQL("DELETE from VazamentosToSQL where vazID = '" + elementos.get(position).getVazID() + "'");
                //bd.close();



                //elementos.remove(position);
                Toast.makeText(context, "ID: "+elementos.get(position).getVazID(),Toast.LENGTH_LONG).show();
                bd.deleteVazamentos(VazamentosToSQL);



                holder.swipeLayout.close();
//                activity.updateAdapter(); //Executa o método "updateAdapter()" na Activity "ExibeVazamentos"
        /**--------------Tried it, not working =( ---------------*/
            }
        };
    }


private class ViewHolder {
        private TextView name;
        private View btnDelete;
        private View btnEdit;
        private SwipeLayout swipeLayout;
        private ListView listv;

        public ViewHolder(View v) {
            swipeLayout = (SwipeLayout)v.findViewById(R.id.swipe_layout);
            btnDelete = v.findViewById(R.id.delete);
            btnEdit = v.findViewById(R.id.edit_query);
            listv = (ListView) v.findViewById(R.id.lvdenuncias);
            swipeLayout.setShowMode(SwipeLayout.ShowMode.PullOut);
        }
    }

提到的图书馆工作得很好。但是当用户根据列表视图选择的行单击按钮时，我试图删除数据库行。使用以下代码：elementos.get(position).getVazID()我得到数据库索引。但我无法从数据库中删除。有人可以帮我编写从数据库中删除行和从列表视图中删除行的代码吗？

标签： androidsqlitelistviewadapter

Answer 1

尝试改变这个：

public int deleteVazamentos(VazamentosToSQL VazamentosToSQL) { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    int i = db.delete(TABELA_VAZAMENTOS, vazID+" =?", new String[] { String.valueOf(VazamentosToSQL.getVazID())}); 
    db.close(); 
    return i; 
}

对此：

public void deleteVazamentos(int vazID) { 
    SQLiteDatabase db = this.getWritableDatabase(); 
    db.delete(TABELA_VAZAMENTOS, "vazID=" + vazID, null); 
}

然后如果你想删除一行，你可以调用：（里面onDeleteListener）

bd.deleteVazamentos(elementos.get(position).getVazID());