刪除listview和sqlite的行

Question

我下面的代碼顯示了listview中sqlite的數據。現在我想寫長按鼠標來刪除listview和sqlite中的行。請幫幫我。我怎樣才能做到這一點？

public class CartList extends ListActivity { 
    private ArrayList<String> results = new ArrayList<String>(); 
    public void onCreate(Bundle bundle) { 
     super.onCreate(bundle); 
     setContentView(com.example.easyshopping.R.layout.cart); 
     openAndQueryDatabase(); 
     displayResultList(); 
    } 
    private void displayResultList() { 
     setListAdapter(new ArrayAdapter<String>(this, 
       R.layout.cartformat,results)); 
       getListView().setTextFilterEnabled(true); } 
     private void openAndQueryDatabase() { 
     try { 
      SQLiteDatabase database = openOrCreateDatabase("ORCL", MODE_PRIVATE, null); 
      Cursor c = database.rawQuery("SELECT title,qty,price FROM CART;", null); 
         if (c != null) { 
       int totalPrice=0; 
       if (c.moveToFirst()) { 
        do { 
         String title = c.getString(c.getColumnIndex("title")); 
         int qty = c.getInt(c.getColumnIndex("qty")); 
         int price = c.getInt(c.getColumnIndex("price")); 
         int pricePerTitle=price*qty; 
         results.add("Title: " + title + ", Quantity: " + qty+", Price: $"+pricePerTitle); 
         totalPrice=totalPrice+pricePerTitle; 
        }while (c.moveToNext()); 
       } 
       TextView tTotalPrice=(TextView)findViewById(com.example.easyshopping.R.id.txttotalprice); 
       String total= Integer.toString(totalPrice); 
       tTotalPrice.setText(total); 
      } 
     } catch (SQLiteException se) { 
      Log.e(getClass().getSimpleName(), "Could not create or Open the database"); 
     }}} 

Answer 1

最好的方法是開發一個自定義適配器。但如果你不想要，這應該工作：

public void onCreate(Bundle bundle) { 
    super.onCreate(bundle); 
    setContentView(com.example.easyshopping.R.layout.cart); 
    openAndQueryDatabase(); 
    displayResultList(); 
    setOnLongClickDelete(); 
} 

private void displayResultList(){ 
    ArrayAdapter<String> listAdapter = new ArrayAdapter<String>(this, R.layout.cartformat,results); 
    setListAdapter(listAdapter); 
    listAdapter.notifyDataSetChanged(); 
    getListView().setTextFilterEnabled(true); 
} 

private void setOnLongClickDelete(){ 
    getListView().setOnItemLongClickListener(new OnItemLongClickListener(){ 
     @Override 
     public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id){ 
      String currentString = results.get(position); 

      String resultRegexString = "Title\\: ([^,]+), Quantity\\: ([^,]+), Price\\: \\$([\\W\\w]+)"; 
      Pattern resultRegexPattern = Pattern.compile(resultRegexString); 
      Matcher resultRegexMatcher = resultRegexPattern.matcher(resultRegexString); 

      if(resultRegexMatcher){ 
       SQLiteDatabase database = openOrCreateDatabase("ORCL", MODE_PRIVATE, null); 
       String whereClause = "title=".concat(DatabaseUtils.sqlEscapeString(resultRegexMatcher.group(1)) 
            .concat(" AND qty=").concat(resultRegexMatcher.group(2)) 
            .concat(" AND price=").concat(resultRegexMatcher.group(3)); 

       database.delete("CART", whereClause, null); 
      } 
     } 
     results.remove(position); 
     displayResultList(); 
    }); 
}