java - 如何停止 toast 和 alertDialog 失去对我的 EditText 过滤器的关注

Question

更新:

最新更新 - 添加了 getChanges() 方法。

第二次更新 - 我添加了整个 ShoppingList.java 类。

第一次更新 - 在 2 个人喜欢这个问题但没有答案之后，我已经为这个问题开放了一个赏金。

问题:

我遇到过类似的问题，一旦我开始一个新的 Intent 然后返回到原始页面，我就无法重新过滤我的 ListView。这是通过使用覆盖 onResume() 方法并从另一个过滤器方法中调用我的过滤器代码来解决的。

我遇到的最新问题是，如果在我的应用程序页面上使用 dialogBu​​ilder 或 toast 消息，那么过滤器文本将再次空白，即输入到我的过滤器 EditText 中的任何文本都将被我的过滤器忽略。

以下是突出显示问题的一些屏幕截图:

已加载项目的 ListView:

搜索词被输入到过滤器 EditText 中并正确过滤:

第一项“A”被编辑为“AB”。 toast 消息确认操作:

这就是问题所在，dialogbuilder(这是编辑项目的方式)和 toast 消息已完成，一个新的过滤词被输入到 EditText 中，过滤器不再过滤:

这是我的过滤器代码:

package com.example.flybaseapp;



    public class ShoppingList extends ListActivity implements OnClickListener {

Button AddItem;
Button showShop;
ListView showItems;
SimpleCursorAdapter cursorAdapter;
Long itemId;
TextView totalPrice;
String itemDescription;
int itemAmount;
int itemPrice;
EditText itemNameEdit;
DBHandlerShop getCons;
Dialog e1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.shoppinglistlayout);

    AddItem = (Button) findViewById(R.id.btnAddItem);
    showShop = (Button) findViewById(R.id.btnSearchShops);

    showItems = (ListView) findViewById(android.R.id.list);

    totalPrice = (TextView) findViewById(R.id.totalListPrice);

    AddItem.setOnClickListener(this);
    showShop.setOnClickListener(this);

    setList();

    int setPrice = updateTotal();
    totalPrice.setText(Integer.toString(setPrice));

    itemNameEdit = (EditText) findViewById(R.id.inputItemName);

    showItems.setTextFilterEnabled(true);

    itemNameEdit.addTextChangedListener(new TextWatcher() {

        @Override
        public void afterTextChanged(Editable s) {

        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {

            cursorAdapter.getFilter().filter(s.toString());
            showItems.refreshDrawableState();

        }

    });

    getCons = new DBHandlerShop(this, null, null);
    getCons.open();
    cursorAdapter.setFilterQueryProvider(new FilterQueryProvider() {

        public Cursor runQuery(CharSequence constraint) {

            return getCons.getChanges((constraint.toString()));

        }

    });

    showItems.setAdapter(cursorAdapter);

}

@Override
public void onClick(View clickedAdd) {

    switch (clickedAdd.getId()) {

    case (R.id.btnAddItem):

        show();

        break;

    case (R.id.btnSearchShops):

        Intent checkGPS = new Intent("com.example.flybaseapp.CheckGPS");
        startActivity(checkGPS);

        break;

    }

}

@Override
protected void onListItemClick(ListView l, View v, int position, long idd) {
    super.onListItemClick(l, v, position, idd);

    itemId = idd;

    final CharSequence[] items = { "Edit Item", "Delete Item" };

    Builder alertDialogBuilder = new AlertDialog.Builder(ShoppingList.this);

    alertDialogBuilder.setTitle("Item Options:");

    alertDialogBuilder.setItems(items,
            new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog, int item) {

                    if (items[item].equals("Edit Item")) {

                        AlertDialog.Builder builder = new AlertDialog.Builder(
                                ShoppingList.this);

                        builder.setTitle("Edit Item");

                        DBHandlerShop setEdit = new DBHandlerShop(
                                ShoppingList.this, null, null);

                        setEdit.open();
                        String itemName = setEdit.getItem(itemId);
                        int itemAmount = setEdit.getItemQuan(itemId);
                        int itemPrice = setEdit.getItemCost(itemId);
                        setEdit.close();

                        LinearLayout layout = new LinearLayout(
                                ShoppingList.this);
                        layout.setOrientation(LinearLayout.VERTICAL);

                        final EditText titleBox = new EditText(
                                ShoppingList.this);
                        titleBox.setText(itemName);
                        titleBox.setHint("Item Name:");
                        layout.addView(titleBox);

                        final EditText quantityBox = new EditText(
                                ShoppingList.this);
                        quantityBox.setText(Integer.toString(itemAmount));
                        quantityBox.setHint("Item Quantity");
                        layout.addView(quantityBox);

                        final EditText priceBox = new EditText(
                                ShoppingList.this);
                        priceBox.setText(Integer.toString(itemPrice));
                        priceBox.setHint("Item Price.");
                        layout.addView(priceBox);

                        builder.setView(layout);

                        builder.setPositiveButton("Ok",
                                new DialogInterface.OnClickListener() {
                                    public void onClick(
                                            DialogInterface dialog,
                                            int whichButton) {

                                        Editable valueItem = titleBox
                                                .getText();
                                        Editable valueAmount = quantityBox
                                                .getText();
                                        Editable valuePrice = priceBox
                                                .getText();

                                        String itemDescription = valueItem
                                                .toString();
                                        String s = valueAmount.toString();
                                        int itemAmount = Integer
                                                .parseInt(s);
                                        String a = valuePrice.toString();
                                        int itemPrice = Integer.parseInt(a);

                                        try {
                                            DBHandlerShop update = new DBHandlerShop(
                                                    ShoppingList.this,
                                                    null, null);

                                            int totalCombined = itemAmount
                                                    * itemPrice;

                                            update.open();
                                            update.updateItem(itemId,
                                                    itemDescription,
                                                    itemAmount, itemPrice);
                                            update.close();

                                            int setPrice = updateTotal();
                                            totalPrice.setText(Integer
                                                    .toString(setPrice));

                                        } catch (Exception e) {

                                            Toast.makeText(
                                                    getApplicationContext(),
                                                    "Items not updated.",
                                                    Toast.LENGTH_SHORT)
                                                    .show();

                                        } finally {

                                            Toast.makeText(
                                                    getApplicationContext(),
                                                    "Items updated.",
                                                    Toast.LENGTH_SHORT)
                                                    .show();

                                            setList();

                                        }

                                    }

                                });

                        builder.setNegativeButton("Cancel",
                                new DialogInterface.OnClickListener() {
                                    public void onClick(
                                            DialogInterface dialog,
                                            int whichButton) {

                                    }
                                });

                        builder.show();

                    }

                    else if (items[item].equals("Delete Item")) {
                        try {

                            DBHandlerShop delete = new DBHandlerShop(
                                    ShoppingList.this, null, null);

                            delete.open();
                            delete.deleteItem(itemId);
                            delete.close();

                            DBHandlerShop findPrice = new DBHandlerShop(
                                    ShoppingList.this, null, null);

                            findPrice.open();
                            int returnedCost = findPrice
                                    .getItemCost(itemId);
                            findPrice.close();

                            int cost = updateTotal();

                            int newTotal = cost - returnedCost;
                            totalPrice.setText(Integer.toString(newTotal));
                        }

                        catch (Exception e) {

                            Toast.makeText(getApplicationContext(),
                                    "Item failed to be deleted.",
                                    Toast.LENGTH_SHORT).show();
                        }

                        finally {

                            Toast.makeText(getApplicationContext(),
                                    "Item deleted from the list.",
                                    Toast.LENGTH_SHORT).show();

                            setList();
                        }

                    }

                }

            });

    alertDialogBuilder.show();

}

@SuppressWarnings("deprecation")
private void setList() {

    DBHandlerShop DBShop = new DBHandlerShop(this, null, null);

    DBHandlerShop searchItems = new DBHandlerShop(this, null, null);

    searchItems.open();

    Cursor cursor = searchItems.getItems();

    startManagingCursor(cursor);

    searchItems.close();

    String[] from = new String[] { DBShop.KEY_ITEMSHOP, DBShop.KEY_ITEMNUM,
            DBShop.KEY_ITEMPRICE };
    int[] to = new int[] { R.id.txtSetItem, R.id.txtSetAmount,
            R.id.txtSetPrice };

    cursorAdapter = new SimpleCursorAdapter(this, R.layout.setshoppinglist,
            cursor, from, to);
    showItems.setAdapter(cursorAdapter);

}

private int updateTotal() {

    DBHandlerShop total = new DBHandlerShop(this, null, null);

    int totalPrice = 0;
    total.open();
    Cursor totalPrices = total.getTotals();
    total.close();

    if (totalPrices != null) {

        startManagingCursor(totalPrices);
        if (totalPrices.moveToFirst()) {

            do {
                int cost = totalPrices.getInt(3);
                int amount = totalPrices.getInt(2);

                int totalCost = cost * amount;
                totalPrice += totalCost;

            } while (totalPrices.moveToNext());

            return totalPrice;
        }

    }

    else {

        return totalPrice;

    }

    return 0;

}

private void show() {

    AlertDialog.Builder builder = new AlertDialog.Builder(ShoppingList.this);

    builder.setTitle("Enter Item Details:");

    LinearLayout layout = new LinearLayout(this);
    layout.setOrientation(LinearLayout.VERTICAL);

    final EditText titleBox = new EditText(this);

    titleBox.setHint("Item Name:");
    layout.addView(titleBox);

    final EditText quantityBox = new EditText(this);

    quantityBox.setHint("Item Quantity");
    layout.addView(quantityBox);

    final EditText priceBox = new EditText(this);

    priceBox.setHint("Item Price.");
    layout.addView(priceBox);

    builder.setView(layout);

    builder.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialog, int whichButton) {
            try {

                Editable valueItem = titleBox.getText();
                Editable valueAmount = quantityBox.getText();
                Editable valuePrice = priceBox.getText();

                itemDescription = valueItem.toString();
                String s = valueAmount.toString();
                itemAmount = Integer.parseInt(s);
                String a = valuePrice.toString();
                itemPrice = Integer.parseInt(a);

                DBHandlerShop addItem = new DBHandlerShop(
                        ShoppingList.this, null, null);
                addItem.open();
                addItem.insertItems(itemDescription, itemAmount, itemPrice);
                addItem.close();

            } catch (Exception e) {

                Toast.makeText(getApplicationContext(),
                        "Item failed to be added", Toast.LENGTH_SHORT)
                        .show();

            } finally {

                Toast.makeText(getApplicationContext(),
                        "Item added to your list", Toast.LENGTH_SHORT)
                        .show();

                int cost = updateTotal();
                totalPrice.setText(Integer.toString(cost));

                setList();

            }

        }

    });

    builder.setNegativeButton("Cancel",
            new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int whichButton) {

                }
            });

    builder.show();

}

@Override
protected void onResume() {
    super.onResume();

    setList();

    showItems.setTextFilterEnabled(true);

    itemNameEdit.addTextChangedListener(new TextWatcher() {

        @Override
        public void afterTextChanged(Editable s) {

        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {

        }

        @Override
        public void onTextChanged(CharSequence s, int start, int before,
                int count) {

            cursorAdapter.getFilter().filter(s.toString());
            showItems.refreshDrawableState();

        }

    });

    getCons = new DBHandlerShop(this, null, null);
    getCons.open();
    cursorAdapter.setFilterQueryProvider(new FilterQueryProvider() {

        public Cursor runQuery(CharSequence constraint) {

            return getCons.getChanges((constraint.toString()));

        }

    });

    showItems.setAdapter(cursorAdapter);
}

}

来自数据库处理程序类的 getChanges():

public Cursor getChanges(String constraintPassed) {

        String [] columns = new String[]{KEY_ROWSHOPID, KEY_ITEMSHOP, KEY_ITEMNUM, KEY_ITEMPRICE};
        Cursor c = null;
         if(constraintPassed.equals(""))
         {
             c = ourDatabase.query(DATABASE_TABLESHOP, columns, null, null, null, null, null);

         }

         else
         {
            c = ourDatabase.query(DATABASE_TABLESHOP, columns, KEY_ITEMSHOP + " LIKE'" + constraintPassed + "%'", null, null, null, KEY_ITEMSHOP + " ASC", null);
         }

        if( c != null)
            {
                c.moveToFirst();

            }
        return c;
    }

编辑完成后是否需要实现生命周期方法？如果可以，有人可以将我推向正确的方向，因为我已经尝试过 onResume() 和 onRestart() 无济于事。

Answer 1

更新过滤器后，尝试在您的适配器上调用 notifyDataSetChanged()。这应该通知 ListView 它也需要刷新其数据。