【发布时间】：2013-03-17 13:21:21
【问题描述】：
更新：
最新更新 - 已添加 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后，我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意图然后返回到原始页面，我就无法重新过滤我的 ListView。这通过使用覆盖 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。
我遇到的最新问题是是否应该在我的应用页面上使用 dialogBuilder 或 toast 消息，然后过滤器文本再次被空白，即输入到我的过滤器 EditText 的任何文本都被我的过滤器忽略。
以下是一些突出问题的屏幕截图：
加载项的ListView：
在过滤器EditText中输入搜索词并正确过滤：
第一个项目“A”被编辑为“AB”。 Toast 消息确认操作：
这是问题所在，对话框生成器（项目的编辑方式）和 toast 消息已完成，在 EditText 中输入了一个新的过滤器术语，过滤器不再过滤：
这是我的过滤代码：
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施生命周期方法？如果是这样，有人可以将我推向正确的方向，因为我尝试过 onResume() 和 onRestart() 无济于事。
【问题讨论】：
-
向我们展示更多代码.....
-
@DhavalSodhaParmar 我已经添加了整个 ShoppingList 类代码。
-
getChanges()方法长什么样子？ -
@Luksprog 非常感谢您的回答。我添加了 getChanges()。它基本上用作我的数据库处理程序类中的一种方法，用于从我的数据库中返回与过滤器术语匹配的任何结果。