arraylist - 无法启动活动 ComponentInfo - 由编辑 ArrayList 中的对象引起
问题描述
我正在构建一个与 SQLite 数据库一起使用以跟踪项目列表的应用程序。项目也存储在 ArrayList (productArrayList) 中。我达到了字符数限制，所以将把描述和一些组件放在线程中。
购物清单适配器：
public class ShoppingListAdapter extends ArrayAdapter<Product> {
private Cursor adapterCursor;
private ShoppingList correspondingShoppingList;
private static final String CHECK_BOX_SHARED_PREFS = "checkBoxPrefs";
public ShoppingListAdapter(@NonNull Context context, ArrayList<Product> products, Cursor curs, ShoppingList corrShList) {
super(context, 0, products);
adapterCursor = curs;
correspondingShoppingList = corrShList;
}
@NonNull
@Override
public View getView(final int position, @Nullable View convertView, @NonNull ViewGroup parent) {
final Product product = getItem(position);
if(convertView == null){
convertView = LayoutInflater.from(getContext()).inflate(R.layout.item_shopping_list, parent, false);
}
Button btnDeleteProduct = convertView.findViewById(R.id.btn_delete_item);
TextView viewName = convertView.findViewById(R.id.view_name_item);
TextView viewInstances = convertView.findViewById(R.id.view_instances_item);
final CheckBox checkBox = convertView.findViewById(R.id.check_box_item);
viewName.setText(product.name);
if (product.instances <= 0) {
viewInstances.setText("");
} else {
viewInstances.setText(" x " + String.valueOf(product.instances));
}
btnDeleteProduct.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
remove(product);
correspondingShoppingList.saveList();
}
});
checkBox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
saveCheckBoxState(product.productID, position, checkBox.isChecked()); // before was the _ID, now it is position
}
});
loadCheckBoxState(product.productID, checkBox);
return convertView;
}
private void saveCheckBoxState(long id, int position, Boolean checkBoxIsChecked) { // remove the position parameter if it does not work
correspondingShoppingList.setCheckBoxStateInList(position, checkBoxIsChecked); // Used to get around the lack of
notifyDataSetChanged(); // call by reference
SharedPreferences shPrefs = getContext().getSharedPreferences (CHECK_BOX_SHARED_PREFS, Context.MODE_PRIVATE);
SharedPreferences.Editor prefEdit = shPrefs.edit();
prefEdit.putBoolean(Long.toString(id), checkBoxIsChecked);
prefEdit.apply();
}
private void loadCheckBoxState(long id, CheckBox cb){
SharedPreferences shPrefs = getContext().getSharedPreferences(CHECK_BOX_SHARED_PREFS, Context.MODE_PRIVATE);
boolean checked = shPrefs.getBoolean(Long.toString(id), false);
cb.setChecked(checked);
}
public void changeCursor(Cursor replacementCurs){ // replaces adapterCursor with replacementCurs
if (adapterCursor != null){
adapterCursor.close();
}
adapterCursor = replacementCurs;
if (replacementCurs!= null){
notifyDataSetChanged(); // sent notification to the shopping list RecyclerView
}
}
public int getItemCount() { // returns the amount of items present at the moment of enquiry
return adapterCursor.getCount();
}
}
转移菜单：
public class TransferMenu extends AppCompatActivity {
private TextView viewProductName;
private TextView viewProductAmount;
private TextView viewDate;
private Button btnMinus;
private Button btnPlus;
private Button btnCancel;
private Button btnSelectDate;
private Button btnAddItem;
private DatePickerDialog.OnDateSetListener datePickerDiagListener;
private ArrayList<Product> receivedShoppingList;
private String LIST_VIEW_SHARED_PREFS_KEY;
private int amount = 0;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_transfer_menu);
viewProductName = findViewById(R.id.view_product_name_transfer);
viewProductAmount = findViewById(R.id.view_amount_transfer);
viewDate = findViewById(R.id.view_date_transfer);
btnMinus = findViewById(R.id.btn_minus_transfer);
btnPlus = findViewById(R.id.btn_plus_transfer);
btnCancel = findViewById(R.id.btn_cancel_transfer);
btnSelectDate = findViewById(R.id.btn_select_date_transfer);
btnAddItem = findViewById(R.id.btn_add_item_transfer);
receivedShoppingList = (ArrayList<Product>) getIntent().getSerializableExtra("listReference");
LIST_VIEW_SHARED_PREFS_KEY = getIntent().getStringExtra("sharedPrefsKey");
System.out.println("TransferMenu:");
ShoppingList.printList(receivedShoppingList); //works
processTickedCheckBoxes();
btnMinus.setOnClickListener(new View.OnClickListener() { // decrement (short push)
@Override
public void onClick(View v) {
decreaseAmountBy(1);
}
});
btnMinus.setOnLongClickListener(new View.OnLongClickListener() { // remove 10 units (long push)
@Override
public boolean onLongClick(View v) {
decreaseAmountBy(10);
return true;
}
});
btnPlus.setOnClickListener(new View.OnClickListener() { // increment (short push)
@Override
public void onClick(View v) {
increaseAmountBy(1);
}
});
btnPlus.setOnLongClickListener(new View.OnLongClickListener() { // add 10 units (long push)
@Override
public boolean onLongClick(View v) {
increaseAmountBy(10);
return true;
}
});
/*btnMinus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
receivedShoppingList.remove(0); // for testing, will be changed later
ShoppingList.printList(receivedShoppingList);
}
});*/
btnCancel.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent shoppingListIntent = new Intent(TransferMenu.this, ShoppingList.class);
SharedPreferences shPrefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor prefEdit = shPrefs.edit();
Gson gson = new Gson();
String arrInJsonForm = gson.toJson(receivedShoppingList);
prefEdit.putString(LIST_VIEW_SHARED_PREFS_KEY, arrInJsonForm);
prefEdit.commit();
startActivity(shoppingListIntent);
}
});
btnSelectDate.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Calendar calendar = Calendar.getInstance();
int day = calendar.get(Calendar.DAY_OF_MONTH);
int month = calendar.get(Calendar.MONTH);
int year = calendar.get(Calendar.YEAR);
DatePickerDialog dpDiag = new DatePickerDialog(TransferMenu.this,
android.R.style.Theme_Holo_Light_Dialog,
datePickerDiagListener,
year, month, day);
dpDiag.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
dpDiag.show();
}
});
datePickerDiagListener = new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
viewDate.setText(dayOfMonth + "/" + month + "/" + year);
}
};
}
private void decreaseAmountBy(int value) {
amount = amount - value;
if (amount >= 1) { // if the user decrements the amount when it is equal to 1, the amount will be displayed
viewProductAmount.setText("Amount: " + amount); // as "N/A" and the amount variable will be equal to 0 until it is incremented
} else {
viewProductAmount.setText("Amount: N/A"); // if amount is set to 0, it shows up as N/A
amount = 0; // in case amount is not applicable, set the variable to 0
}
}
private void increaseAmountBy(int value) {
amount = amount + value;
viewProductAmount.setText("Amount: " + amount);
}
private void processTickedCheckBoxes() {
for (int i = 0; i < receivedShoppingList.size(); i++){
Product product = receivedShoppingList.get(i);
if (product.checkBoxIsChecked){
amount = product.instances;
viewProductName.setText(product.name);
viewProductAmount.setText(amount);
while (!btnAddItem.isPressed()){} // used to pause the loop until the item is added to the user inventory or the action is cancelled
amount = 0;
viewProductAmount.setText(amount);
viewDate.setText("Expiry Date");
}
}
}
private void addProductToInventory(Product product) {
}
}
表字符串：
public class TableStrings {
private TableStrings(){} // empty constructor because this class does not need to be instantiated
public static final class ShoppingListStrings implements BaseColumns { // one inner class for each table
public static final String TABLE_NAME_SHOPPING_LIST = "shoppingList";
public static final String COLUMN_NAME_SHOPPING_LIST = "productNameShoppingList";
public static final String COLUMN_AMOUNT_SHOPPING_LIST = "amountShoppingList";
public static final String COLUMN_TIMESTAMP_SHOPPING_LIST = "timeShoppingList";
}
public static final class UserInventoryStrings implements BaseColumns{
public static final String TABLE_NAME_USER_INVENTORY = "userInventory";
public static final String COLUMN_NAME_USER_INVENTORY = "productNameUserInventory";
public static final String COLUMN_AMOUNT_USER_INVENTORY = "amountUserInventory";
public static final String COLUMN_TIMESTAMP_USER_INVENTORY = "timeUserInventory";
public static final String COLUMN_EXPIRATION_DATE_USER_INVENTORY = "expirationDateUserInventory";
}
}
现在，布局：
活动主.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ImageView
android:id="@+id/view_img_main_menu"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:src="@drawable/grocery_img_1" />
<Button
android:id="@+id/btn_inventory"
android:layout_width="match_parent"
android:layout_height="65dp"
android:layout_below="@id/view_img_main_menu"
android:text="@string/btn_my_groceries_text"
style="@style/BtnStyle" />
<Button
android:id="@+id/btn_shopping_list"
android:layout_width="match_parent"
android:layout_height="65dp"
android:layout_below="@id/btn_inventory"
android:text="@string/btn_shopping_list_text"
style="@style/BtnStyle" />
<Button
android:id="@+id/btn_how_to_use"
android:layout_width="match_parent"
android:layout_height="65dp"
android:layout_below="@id/btn_shopping_list"
android:text="@string/btn_how_to_use_text"
style="@style/BtnStyle" />
<Button
android:id="@+id/btn_credits"
android:layout_width="match_parent"
android:layout_height="65dp"
android:layout_below="@id/btn_how_to_use"
android:text="@string/btn_credits_text"
style="@style/BtnStyle" />
</RelativeLayout>
activity_shopping_list.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
tools:context=".ShoppingList">
<ImageView
android:id="@+id/view_img_shopping_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:src="@drawable/grocery_img_2" />
<TextView
android:id="@+id/view_amount"
style="@style/TextViewStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/view_img_shopping_list"
android:layout_centerInParent="true"
android:layout_marginStart="10dp"
android:layout_marginTop="4dp"
android:gravity="center"
android:text="@string/amount_default_label"
android:textSize="25dp" />
<EditText
android:id="@+id/edit_text"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/view_amount"
android:gravity="center" />
<LinearLayout
android:id="@+id/btn_layout_upper"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/edit_text"
android:layout_marginStart="5dp"
android:layout_marginTop="1dp"
android:layout_marginEnd="5dp">
<Button
android:id="@+id/btn_minus"
style="@style/BtnStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/view_title"
android:layout_weight="1"
android:text="-"
android:textSize="20dp" />
<Button
android:id="@+id/btn_plus"
style="@style/BtnStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/view_title"
android:layout_weight="1"
android:text="+"
android:textSize="20dp" />
</LinearLayout>
<LinearLayout
android:id="@+id/btn_layout_lower"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/btn_layout_upper"
android:layout_marginStart="5dp"
android:layout_marginEnd="5dp">
<Button
android:id="@+id/btn_back"
style="@style/BtnStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/view_title"
android:layout_weight="1"
android:text="@string/btn_inventory_back_label" />
<Button
android:id="@+id/btn_add"
style="@style/BtnStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/view_title"
android:layout_weight="1"
android:text="@string/btn_inventory_add_label" />
</LinearLayout>
<TextView
android:id="@+id/view_title"
style="@style/TextViewStyle"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_below="@id/btn_layout_lower"
android:layout_centerHorizontal="true"
android:layout_marginStart="10dp"
android:layout_marginTop="5dp"
android:gravity="center"
android:text="@string/shopping_list_label"
android:textSize="32dp" />
<ListView
android:id="@+id/view_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="@id/view_title"
android:layout_alignParentStart="true"
android:layout_alignParentBottom="true"
android:layout_centerVertical="true"
android:layout_marginStart="1dp"
android:layout_marginTop="5dp"
android:layout_marginBottom="0dp" />
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentStart="true"
android:layout_alignParentEnd="true"
android:layout_alignParentBottom="true"
android:layout_marginStart="312dp"
android:layout_marginEnd="14dp"
android:layout_marginBottom="10dp">
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/btn_float_delete"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="top"
android:layout_marginStart="16dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:layout_marginBottom="85dp"
android:src="@drawable/shopping_list_icon_delete"
app:layout_anchor="@id/btn_float_save"
app:fabCustomSize="50dp"
app:layout_anchorGravity="top" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="@+id/btn_float_save"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="left|bottom"
android:layout_margin="16dp"
android:src="@drawable/shopping_list_icon_save"
app:fabCustomSize="50dp" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
</RelativeLayout>
item_shopping_list.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<Button
android:id="@+id/btn_delete_item"
style="@style/BtnStyle"
android:layout_width="35dp"
android:layout_height="35dp"
android:textSize="12sp"
android:text="X" />
<TextView
android:id="@+id/view_name_item"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="2dp"
android:text="empty_item"
android:layout_toEndOf="@+id/btn_delete_item"
android:textSize="20sp" />
<TextView
android:id="@+id/view_instances_item"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_marginStart="8dp"
android:layout_marginTop="2dp"
android:layout_toEndOf="@+id/view_name_item"
android:text="x amount"
android:textSize="20sp" />
<CheckBox
android:id="@+id/check_box_item"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:layout_alignParentEnd="true"
android:layout_marginStart="4dp"
android:layout_marginTop="1dp"
android:layout_toEndOf="@+id/view_instances_item" />
</RelativeLayout>
activity_transfer_menu.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".TransferMenu">
<ImageView
android:id="@+id/view_img_shopping_list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:src="@drawable/grocery_img_2" />
<TextView
android:id="@+id/view_product_name_transfer"
style="@style/TextViewStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/view_img_shopping_list"
android:layout_centerInParent="true"
android:layout_marginStart="10dp"
android:layout_marginTop="4dp"
android:gravity="center"
android:text="@string/item_default_label_transfer"
android:textSize="25dp" />
<TextView
android:id="@+id/view_amount_transfer"
style="@style/TextViewStyle"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/view_product_name_transfer"
android:layout_centerInParent="true"
android:layout_marginStart="10dp"
android:layout_marginTop="4dp"
android:gravity="center"
android:text="@string/amount_default_label"
android:textSize="25dp" />
<LinearLayout
android:id="@+id/btn_layout_transfer_upper"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/view_amount_transfer"
android:layout_marginStart="5dp"
android:layout_marginTop="1dp"
android:layout_marginEnd="5dp">
<Button
android:id="@+id/btn_minus_transfer"
style="@style/BtnStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/view_title"
android:layout_weight="1"
android:text="-"
android:textSize="20dp" />
<Button
android:id="@+id/btn_plus_transfer"
style="@style/BtnStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/view_title"
android:layout_weight="1"
android:text="+"
android:textSize="20dp" />
</LinearLayout>
<TextView
android:id="@+id/view_date_transfer"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/btn_layout_transfer_upper"
android:gravity="center"
android:text="Expiry Date"
android:textSize="40sp" />
<LinearLayout
android:id="@+id/btn_layout_transfer_lower"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="@id/view_date_transfer"
android:layout_marginStart="5dp"
android:layout_marginTop="1dp"
android:layout_marginEnd="5dp">
<Button
android:id="@+id/btn_cancel_transfer"
style="@style/BtnStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/view_title"
android:layout_weight="1"
android:text="Cancel"
android:textAllCaps="false"
android:textSize="20dp" />
<Button
android:id="@+id/btn_select_date_transfer"
style="@style/BtnStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/view_title"
android:layout_weight="1"
android:text="Select Date"
android:textAllCaps="false"
android:textSize="20dp" />
<Button
android:id="@+id/btn_add_item_transfer"
style="@style/BtnStyle"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="@id/view_title"
android:layout_weight="1"
android:text="Add item"
android:textAllCaps="false"
android:textSize="20dp" />
</LinearLayout>
</RelativeLayout>
我怀疑这个问题与数据库有关，因为导致它的布尔值与它没有任何关系，但我包括了这些类以防万一。我尝试了其他人发布的解决方案，例如重建和清理项目，但他们没有解决问题。我将问题追溯到前面提到的 setCheckBoxStateInList() 方法，并在导致它的行中添加了注释。为什么会出现这个错误？
解决方案
更多信息在这里，因为我达到了字符限制。
产品对象有一个属性，它跟踪其 CheckBox 的状态（在 setCheckBoxStateInList() 方法中修改此属性会导致崩溃），称为 checkBoxIsChecked。该列表被发送到另一个活动，并且带有勾选复选框的项目应该被添加到另一个数据库。复选框在 ShoppingListAdapter 类中具有侦听器，但在 TransferMenu 活动中，检查是基于 checkBoxIsChecked 属性的值完成的，因此也需要更新。我发现这样做的唯一方法是在 ShoppingList 活动中（在 setCheckBoxStateInList() 方法中）。只要没有将 checkBoxIsChecked 属性设置为 true，当单击保存 FloatingActionButton（带有软盘的按钮）时，TransferMenu 活动就会按预期启动。当其中一个属性设置为 true 时，错误被抛出。我看到的与此错误有关的其他问题与应用程序主题或其他 XML 内容有关，但我没有看到与我遇到的情况类似的情况。如果需要更多代码，请告诉我：
主要活动：
public class MainActivity extends AppCompatActivity {
private Button btnInventory;
private Button btnShopList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnInventory = findViewById(R.id.btn_inventory);
btnShopList = findViewById(R.id.btn_shopping_list);
btnInventory.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent inventoryIntent = new Intent(MainActivity.this, Inventory.class);
startActivity(inventoryIntent);
}
});
btnShopList.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent shopListIntent = new Intent(MainActivity.this, ShoppingList.class);
startActivity(shopListIntent);
}
});
}
`}`
购物清单：
public class ShoppingList extends AppCompatActivity {
private EditText editText;
private TextView viewAmount;
private Button btnMinus;
private Button btnPlus;
private Button btnBack;
private Button btnAdd;
private FloatingActionButton btnFloatDelete;
private FloatingActionButton getBtnFloatSave;
private SQLiteDatabase shoppingListDB;
private ShoppingListAdapter listAdapter;
private ArrayList<Product> productArrayList;
private int amount = 1;
public static final String LIST_VIEW_SHARED_PREFS_KEY = "listViewPrefs";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_shopping_list);
getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN); // to make the FloatingActionButtons stay fixed when the keyboard goes up.
ShoppingListDatabaseHelper listDBHelper = new ShoppingListDatabaseHelper(this);
shoppingListDB = listDBHelper.getWritableDatabase(); // assign a database to shoppingListDB that can be written to
loadList();
final ListView shopListView = findViewById(R.id.view_list);
listAdapter = new ShoppingListAdapter(this, productArrayList, getFullListCursor(), this);
shopListView.setAdapter(listAdapter);
editText = findViewById(R.id.edit_text);
viewAmount = findViewById(R.id.view_amount);
btnMinus = findViewById(R.id.btn_minus);
btnPlus = findViewById(R.id.btn_plus);
btnBack = findViewById(R.id.btn_back);
btnAdd = findViewById(R.id.btn_add);
btnFloatDelete = findViewById(R.id.btn_float_delete);
getBtnFloatSave = findViewById(R.id.btn_float_save);
viewAmount.setText("Amount: " + amount);
btnMinus.setOnClickListener(new View.OnClickListener() { // decrement (short push)
@Override
public void onClick(View v) {
decreaseAmountBy(1);
}
});
btnMinus.setOnLongClickListener(new View.OnLongClickListener() { // remove 10 units (long push)
@Override
public boolean onLongClick(View v) {
decreaseAmountBy(10);
return true;
}
});
btnPlus.setOnClickListener(new View.OnClickListener() { // increment (short push)
@Override
public void onClick(View v) {
increaseAmountBy(1);
}
});
btnPlus.setOnLongClickListener(new View.OnLongClickListener() { // add 10 units (long push)
@Override
public boolean onLongClick(View v) {
increaseAmountBy(10);
return true;
}
});
btnBack.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent mainActIntent = new Intent(ShoppingList.this, MainActivity.class);
startActivity(mainActIntent);
}
});
btnAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
addItem();
}
});
btnFloatDelete.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
deleteAllItems();
}
});
getBtnFloatSave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent transferMenuIntent = new Intent(ShoppingList.this, TransferMenu.class);
transferMenuIntent.putExtra("listReference", productArrayList);
transferMenuIntent.putExtra("sharedPrefsKey", LIST_VIEW_SHARED_PREFS_KEY);
startActivity(transferMenuIntent);
}
});
}
private Cursor getFullListCursor(){
Cursor fullListCursor = shoppingListDB.query(ShoppingListStrings.TABLE_NAME_SHOPPING_LIST,
null,
null,
null,
null,
null,
ShoppingListStrings.COLUMN_TIMESTAMP_SHOPPING_LIST + " DESC");
return fullListCursor;
}
private void decreaseAmountBy(int value) {
amount = amount - value;
if (amount >= 1) { // if the user decrements the amount when it is equal to 1, the amount will be displayed
viewAmount.setText("Amount: " + amount); // as "N/A" and the amount variable will be equal to 0 until it is incremented
} else {
viewAmount.setText("Amount: N/A"); // if amount is set to 0, it shows up as N/A
amount = 0; // in case amount is not applicable, set the variable to 0
}
}
private void increaseAmountBy(int value) {
amount = amount + value;
viewAmount.setText("Amount: " + amount);
}
private void addItem() {
if (editText.getText().toString().trim().length() == 0) { // if editText is empty, adding items is impossible; trim() is used to avoid users doing tricks to add empty entries
return;
}
String itemStr = editText.getText().toString();
ContentValues cVals = new ContentValues(); // used to insert grocery item information into the shopping list database
cVals.put(ShoppingListStrings.COLUMN_NAME_SHOPPING_LIST, itemStr);
if (amount > 0){
cVals.put(ShoppingListStrings.COLUMN_AMOUNT_SHOPPING_LIST, amount);
} else if (viewAmount.getText().toString() == "Amount: N/A"){
cVals.put(ShoppingListStrings.COLUMN_AMOUNT_SHOPPING_LIST, amount - 1);
} else {
return;
}
shoppingListDB.insert(ShoppingListStrings.TABLE_NAME_SHOPPING_LIST, null, cVals);
listAdapter.changeCursor(getFullListCursor());
Product product = new Product(itemStr, amount, false);
listAdapter.add(product);
editText.setText("");
amount = 1;
viewAmount.setText("Amount: " + amount);
saveList();
printList(productArrayList);
//editText.getText().clear();
}
private void deleteAllItems(){
listAdapter.clear();
shoppingListDB.execSQL("DELETE FROM " + ShoppingListStrings.TABLE_NAME_SHOPPING_LIST);
Cursor cursCheck = getFullListCursor();
if (!cursCheck.moveToFirst()){
System.out.println("Shopping List Database is empty");
}
saveList();
printList(productArrayList);
}
// Public methods
public void saveList(){
//SharedPreferences shPrefs = ShoppingList.this.getSharedPreferences(LIST_VIEW_SHARED_PREFS_KEY, Context.MODE_PRIVATE);
SharedPreferences shPrefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
SharedPreferences.Editor prefEdit = shPrefs.edit();
Gson gson = new Gson();
String arrInJsonForm = gson.toJson(productArrayList);
prefEdit.putString(LIST_VIEW_SHARED_PREFS_KEY, arrInJsonForm);
prefEdit.commit();
}
public void loadList(){
//SharedPreferences shPrefs = ShoppingList.this.getSharedPreferences(LIST_VIEW_SHARED_PREFS_KEY, Context.MODE_PRIVATE);
SharedPreferences shPrefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
Gson gson = new Gson();
String arrInJsonForm = shPrefs.getString(LIST_VIEW_SHARED_PREFS_KEY, null);
Type type = new TypeToken<ArrayList<Product>>() {}.getType();
productArrayList = gson.fromJson(arrInJsonForm, type);
if (productArrayList == null){
productArrayList = new ArrayList<Product>();
}
}
public void setCheckBoxStateInList(int index, boolean checkBoxState){
productArrayList.get(index).checkBoxIsChecked = checkBoxState; // This line throws the error. If checkBoxState is replaced with false, no error is thrown.
// If it is replaced with true, the error is thrown as well
saveList();
}
// Testing
public static void printList(ArrayList<Product> productList){
System.out.println("List:");
for (int i = 0; i < productList.size(); i++){
Product product = productList.get(i);
System.out.print(" - " + product.name + " " + product.instances + " (ID: " + product.productID + "); box is ");
if (product.checkBoxIsChecked){
System.out.println("checked");
} else {
System.out.println("not checked");
}
}
System.out.println("End of list\n");
}
}
这是错误：
E/atusapplicatio: Invalid ID 0x0000000b.
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.grocerystatusapplication, PID: 20040
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.grocerystatusapplication/com.example.grocerystatusapplication.TransferMenu}: android.content.res.Resources$NotFoundException: String resource ID #0xb
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3344)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3488)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:83)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2049)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:216)
at android.app.ActivityThread.main(ActivityThread.java:7506)
at java.lang.reflect.Method.invoke(Nati
I/Process: Sending signal. PID: 20040 SIG: 9
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