我正在尝试实现一个简单的待办事项列表应用程序。我在这里使用Realm作为本地数据库。在recyclerview中的cardview项目中，我在左侧创建了Taskname，任务日期，在右侧创建了check，delete选项。现在第一个问题是，当我点击检查选项或删除选项时，应用程序崩溃并显示一条错误消息
已编辑的适配器类
public class TaskAdapter extends RealmRecyclerViewAdapter<Task, TaskAdapter.TaskHolder> {
public final static String INTENT_KEY_POSITION = "position";
public final static String DATE_FORMAT = "dd/MMM/yy";
private Realm realm;
public interface TaskListener {
}
private final TaskListener taskListener;
private final Context context;
public TaskAdapter(TaskListener taskListener, RealmResults<Task> realmResults, Context context) {
super(realmResults, true);
this.taskListener = taskListener;
this.context = context;
}
@Override
public TaskHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return new TaskHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.row_task_list_layout, parent, false));
}
@Override
public void onBindViewHolder(TaskHolder holder, final int position) {
final Task task = getData().get(position);
holder.taskTextView.setText(task.getName());
holder.doneCheckBox.setChecked(task.isDone());
final SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
final Date date = (task.getDate());
if (sdf.format(date).equals(sdf.format(getDate(0))))
holder.dateTextView.setText("Today");
else if (sdf.format(date).equals(sdf.format(getDate(-1))))
holder.dateTextView.setText("Yesterday");
else if (sdf.format(date).equals(sdf.format(getDate(1))))
holder.dateTextView.setText("Tomorrow");
else if (date.getTime() < getDate(6).getTime()) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
holder.dateTextView.setText(DateFormat.format("EEEE", calendar.getTime()).toString());
} else
holder.dateTextView.setText(sdf.format(task.getDate()));
holder.cardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(context, AddTaskActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtra(INTENT_KEY_POSITION, position);
context.startActivity(intent);
}
});
holder.doneCheckBox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Task task = new Task();
task.setId(getTask(position).getId());
task.setDate(getTask(position).getDate());
task.setName(getTask(position).getName());
task.setDone(((CheckBox) v).isChecked());
updateTask(position, task);
}
});
holder.deleteImageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (getTask(position).isDone()) {
removeTask(position);
return;
}
AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);
alertDialog.setTitle("Confirm Delete?");
alertDialog.setMessage("Do you want to delete the task you created?");
alertDialog.setPositiveButton("YES", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
removeTask(position);
}
});
alertDialog.setNegativeButton("NO", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
alertDialog.show();
}
});
}
public class TaskHolder extends RecyclerView.ViewHolder {
public CardView cardView;
public TextView taskTextView;
public TextView dateTextView;
public ImageView deleteImageView;
public CheckBox doneCheckBox;
public TaskHolder(View itemView) {
super(itemView);
taskTextView = (TextView) itemView.findViewById(R.id.row_task_list_tv_name);
dateTextView = (TextView) itemView.findViewById(R.id.row_task_list_tv_date);
deleteImageView = (ImageView) itemView.findViewById(R.id.row_task_list_iv_delete);
doneCheckBox = (CheckBox) itemView.findViewById(R.id.row_task_list_cb_done);
cardView = (CardView) itemView.findViewById(R.id.cardView);
}
}
private Date getDate(int day) {
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DATE, day);
return calendar.getTime();
}
protected Task getTask(int position) {
return getData().get(position);
}
protected void updateTask(int position, Task task) {
realm.beginTransaction();
Task newTask = realm.where(Task.class).equalTo("id", task.getId()).findFirst();
newTask.setDate(task.getDate());
newTask.setDone(task.isDone());
newTask.setName(task.getName());
realm.commitTransaction();
}
protected void removeTask(int position) {
Task newTask = realm.where(Task.class).equalTo("id", getTask(position).getId()).findFirst();
realm.beginTransaction();
newTask.deleteFromRealm();
realm.commitTransaction();
}
}
已编辑的活动类
public class TaskActivity extends AppCompatActivity implements TaskAdapter.TaskListener{
private static final int ADD_TASK_REQUEST_CODE = 1000;
private static final int EDIT_TASK_REQUEST_CODE = 1001;
private Realm realm;
private RecyclerView recyclerView;
private TaskAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tasks);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("ToDo List");
setSupportActionBar(toolbar);
realm = Realm.getDefaultInstance();
recyclerView =(RecyclerView)findViewById(R.id.activity_tasks_ll_task);
setUpRecycler();
// Variables
realm=Realm.getDefaultInstance();
// Views
FloatingActionButton addFloatingActionButton = (FloatingActionButton) findViewById(R.id.activity_tasks_fab_add);
//Listeners
addFloatingActionButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startActivityForResult(new Intent(getApplicationContext(), AddTaskActivity.class), ADD_TASK_REQUEST_CODE);
}
});
}
private void setAdapter() {
adapter = new TaskAdapter(this, realm.where(Task.class).findAllSortedAsync("name"),this);
recyclerView.setAdapter(adapter);
adapter.notifyDataSetChanged();
}
private void setUpRecycler() {
recyclerView.setHasFixedSize(true);
final LinearLayoutManager layoutManager = new LinearLayoutManager(this);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(layoutManager);
setAdapter();
}
}
已编辑的AddActivity类
public class TodoAddActivity extends AppCompatActivity {
// Variables
private Context mContext;
private Realm realm;
private TodoModel task;
private Button button;
private EditText mTaskNameEditText;
private EditText mTaskDateEditText;
private EditText mTaskTimeEditText;
String time;
//private static List<TodoModel> tasks;
public final static String INTENT_KEY_POSITION = "position";
public final static String DATE_FORMAT = "dd/MMM/yy";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView( R.layout.todo_add_layout);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mContext = this;
realm=Realm.getDefaultInstance();
setUpUIViews();
showData();
final int position = getIntent().getIntExtra(INTENT_KEY_POSITION, -1);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (TodoModel.ID == -1)
addTask();
else
editTask(position);
}
});
mTaskDateEditText.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
datePicker(view);
}
});
mTaskDateEditText.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View view, boolean b) {
if (b)
datePicker(view);
}
});
mTaskTimeEditText.setOnClickListener( new View.OnClickListener() {
@Override
public void onClick(View view) {
timePicker( view );
}
} );
mTaskTimeEditText.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View view, boolean b) {
if (b)
timePicker( view );
}
});
if (position != -1) {
fillTask(getTask(position)); //how can i modify this line
button.setText("EDIT");
}
}
private void setUpUIViews() {
button = (Button) findViewById(R.id.activity_add_task_bt_add);
mTaskNameEditText = (EditText) findViewById(R.id.activity_add_task_et_name);
mTaskDateEditText = (EditText) findViewById(R.id.activity_add_task_et_date);
mTaskTimeEditText = (EditText) findViewById(R.id.activity_add_task_et_time);
}
public void showData(){
RealmResults<TodoModel> tasksResult = realm.where(TodoModel.class).findAll();
}
private void fillTask(TodoModel task) {
mTaskNameEditText.setText(task.getName());
SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
mTaskDateEditText.setText(sdf.format(task.getDate()));
mTaskTimeEditText.setText(task.getTime());
}
private void addTask() {
String taskName = mTaskNameEditText.getText().toString();
String taskDate = mTaskDateEditText.getText().toString();
String taskTime = mTaskTimeEditText.getText().toString();
if (taskName.length() == 0 || taskName.equals("")) {
mTaskNameEditText.setError("Should be filled");
return;
}
if (taskDate.length() == 0 || taskDate.equals("")) {
mTaskDateEditText.setError("Should be filled");
return;
}
TodoModel task = getTask(taskName, taskDate,taskTime);
if (task == null) {
mTaskDateEditText.setError("Not a correct date");
return;
}
task.setDone(false);
addTask(task);
setResult(RESULT_OK);
finish();
}
protected void addTask(TodoModel task) {
realm.beginTransaction();
TodoModel newTask = realm.createObject(TodoModel.class, UUID.randomUUID().toString());
newTask.setName(task.getName());
newTask.setDate(task.getDate());
newTask.setTime(task.getTime());
realm.copyToRealmOrUpdate(newTask);
realm.commitTransaction();
realm.close();
}
private void editTask(int position) {
String taskName = mTaskNameEditText.getText().toString();
String taskDate = mTaskDateEditText.getText().toString();
String taskTime = mTaskTimeEditText.getText().toString();
if (taskName.length() == 0 || taskName.equals("")) {
mTaskNameEditText.setError("Should be filled");
return;
}
if (taskDate.length() == 0 || taskDate.equals("")) {
mTaskDateEditText.setError("Should be filled");
return;
}
if (taskTime.length() == 0 || taskTime.equals("")) {
mTaskTimeEditText.setError("Should be filled");
return;
}
TodoModel task = getTask(taskName, taskDate,taskTime);
if (task == null) {
mTaskDateEditText.setError("Not a correct date");
return;
}
task.setId(getTask(position).getId());
updateTask(position, task);
setResult(RESULT_OK);
finish();
}
protected void updateTask(int position, TodoModel task) {
realm.beginTransaction();
TodoModel newTask = realm.where(TodoModel.class).equalTo("id", task.getId()).findFirst();
newTask.setDate(task.getDate());
newTask.setDone(task.isDone());
newTask.setName(task.getName());
realm.commitTransaction();
}
private void datePicker(final View view) {
Calendar currentTime = Calendar.getInstance();
int year = currentTime.get(Calendar.YEAR);
int monthOfYear = currentTime.get(Calendar.MONTH);
int dayOfMonth = currentTime.get(Calendar.DAY_OF_MONTH);
DatePickerDialog mDatePickerDialog = new DatePickerDialog(mContext, 0, new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker datePicker, int year, int monthOfYear, int dayOfMonth) {
Calendar calendar = Calendar.getInstance();
calendar.set(year, monthOfYear, dayOfMonth);
SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
((EditText) view).setText(sdf.format(calendar.getTime()));
}
}, year, monthOfYear, dayOfMonth);
mDatePickerDialog.setTitle("Select Time");
mDatePickerDialog.show();
}
private void timePicker(final View view) {
Calendar mcurrentTime = Calendar.getInstance();
int hour = mcurrentTime.get(Calendar.HOUR_OF_DAY);
int minute = mcurrentTime.get(Calendar.MINUTE);
TimePickerDialog mTimePicker;
mTimePicker = new TimePickerDialog(mContext,0, new TimePickerDialog.OnTimeSetListener() {
@Override
public void onTimeSet(TimePicker timePicker, int selectedHour, int selectedMinute) {
mTaskTimeEditText.setText( selectedHour + ":" + selectedMinute);
}
}, hour, minute, true);//Yes 24 hour time
mTimePicker.setTitle("Select Time");
mTimePicker.show();
}
private TodoModel getTask(String name, String dateString,String time) {
TodoModel task = new TodoModel();
try {
SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
task.setName(name);
task.setDate(sdf.parse(dateString));
task.setTime(time );
task.setDone(false);
return task;
} catch (ParseException e) {
e.printStackTrace();
return null;
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == android.R.id.home)
onBackPressed();
return super.onOptionsItemSelected(item);
}
public class TaskCompare implements Comparator<TodoModel> {
@Override
public int compare(TodoModel o1, TodoModel o2) {
return o1.getDate().compareTo(o2.getDate());
}
}
}
答案 0 :(得分：0)
public class TaskAdapter extends RealmRecyclerViewAdapter<Task, TaskAdapter.TaskHolder> {
public final static String INTENT_KEY_POSITION = "position";
public final static String DATE_FORMAT = "dd/MMM/yy";
private Realm realm;
public interface TaskListener {
}
private final TaskListener taskListener;
private final Context context;
public TaskAdapter(TaskListener taskListener, RealmResults<Task> realmResults, Context context, Realm realm) {
super(realmResults, true);
this.taskListener = taskListener;
this.context = context;
this.realm = realm;
}
@Override
public TaskHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return new TaskHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.row_task_list_layout, parent, false));
}
@Override
public void onBindViewHolder(TaskHolder holder, final int position) {
final Task task = getData().get(position);
holder.taskTextView.setText(task.getName());
holder.doneCheckBox.setChecked(task.isDone());
final SimpleDateFormat sdf = new SimpleDateFormat(DATE_FORMAT);
final Date date = (task.getDate());
if (sdf.format(date).equals(sdf.format(getDate(0))))
holder.dateTextView.setText("Today");
else if (sdf.format(date).equals(sdf.format(getDate(-1))))
holder.dateTextView.setText("Yesterday");
else if (sdf.format(date).equals(sdf.format(getDate(1))))
holder.dateTextView.setText("Tomorrow");
else if (date.getTime() < getDate(6).getTime()) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
holder.dateTextView.setText(DateFormat.format("EEEE", calendar.getTime()).toString());
} else
holder.dateTextView.setText(sdf.format(task.getDate()));
holder.cardView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent = new Intent(context, AddTaskActivity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtra(INTENT_KEY_POSITION, position);
context.startActivity(intent);
}
});
holder.doneCheckBox.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Task task = new Task();
task.setId(getTask(position).getId());
task.setDate(getTask(position).getDate());
task.setName(getTask(position).getName());
task.setDone(((CheckBox) v).isChecked());
updateTask(position, task);
}
});
holder.deleteImageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (getTask(position).isDone()) {
removeTask(position);
return;
}
AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);
alertDialog.setTitle("Confirm Delete?");
alertDialog.setMessage("Do you want to delete the task you created?");
alertDialog.setPositiveButton("YES", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
removeTask(position);
}
});
alertDialog.setNegativeButton("NO", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
});
alertDialog.show();
}
});
}
public class TaskHolder extends RecyclerView.ViewHolder {
public CardView cardView;
public TextView taskTextView;
public TextView dateTextView;
public ImageView deleteImageView;
public CheckBox doneCheckBox;
public TaskHolder(View itemView) {
super(itemView);
taskTextView = (TextView) itemView.findViewById(R.id.row_task_list_tv_name);
dateTextView = (TextView) itemView.findViewById(R.id.row_task_list_tv_date);
deleteImageView = (ImageView) itemView.findViewById(R.id.row_task_list_iv_delete);
doneCheckBox = (CheckBox) itemView.findViewById(R.id.row_task_list_cb_done);
cardView = (CardView) itemView.findViewById(R.id.cardView);
}
}
private Date getDate(int day) {
Calendar calendar = Calendar.getInstance();
calendar.add(Calendar.DATE, day);
return calendar.getTime();
}
protected Task getTask(int position) {
return getData().get(position);
}
protected void updateTask(int position, Task task) {
realm.beginTransaction();
Task newTask = realm.where(Task.class).equalTo("id", task.getId()).findFirst();
newTask.setDate(task.getDate());
newTask.setDone(task.isDone());
newTask.setName(task.getName());
realm.commitTransaction();
}
protected void removeTask(int position) {
realm.beginTransaction();
Task newTask = realm.where(Task.class).equalTo("id", getTask(position).getId()).findFirst();
newTask.deleteFromRealm();
realm.commitTransaction();
}
}
和
public class TaskActivity extends AppCompatActivity implements TaskAdapter.TaskListener {
private static final int ADD_TASK_REQUEST_CODE = 1000;
private static final int EDIT_TASK_REQUEST_CODE = 1001;
private Realm realm;
public final static String INTENT_KEY_POSITION = "position";
public final static String DATE_FORMAT = "dd/MMM/yy";
private RecyclerView recyclerView;
private TaskAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_tasks);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("ToDo List");
setSupportActionBar(toolbar);
realm = Realm.getDefaultInstance();
recyclerView =(RecyclerView)findViewById(R.id.activity_tasks_ll_task);
setUpRecycler();
// Views
FloatingActionButton addFloatingActionButton = (FloatingActionButton) findViewById(R.id.activity_tasks_fab_add);
//Listeners
addFloatingActionButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
startActivityForResult(new Intent(getApplicationContext(), AddTaskActivity.class), ADD_TASK_REQUEST_CODE);
}
});
}
private void setAdapter() {
adapter = new TaskAdapter(this, realm.where(Task.class).findAllSortedAsync("date"),this, realm);
recyclerView.setAdapter(adapter);
}
private void setUpRecycler() {
// use this setting to improve performance if you know that changes
// in content do not change the layout size of the RecyclerView
recyclerView.setHasFixedSize(true);
// use a linear layout manager since the cards are vertically scrollable
final LinearLayoutManager layoutManager = new LinearLayoutManager(this);
layoutManager.setOrientation(LinearLayoutManager.VERTICAL);
recyclerView.setLayoutManager(layoutManager);
setAdapter();
}
}
和
public class AddTaskActivity extends AppCompatActivity {
// Variables
private Context mContext;
private Realm realm;
private Button button;
private EditText mTaskNameEditText;
private EditText mTaskDateEditText;
public final static String INTENT_KEY_POSITION = "position";
public final static String DATE_FORMAT = "dd/MMM/yy";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_task);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("Add Task");
setSupportActionBar(toolbar);
getSupportActionBar().setHomeButtonEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
mContext = this;
realm=Realm.getDefaultInstance();
setUpUIViews();
showData();
final int position = getIntent().getIntExtra(INTENT_KEY_POSITION, 0);
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (position == -1)
addTask();
else
editTask(position);
}
});
mTaskDateEditText.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
datePicker(view);
}
});
mTaskDateEditText.setOnFocusChangeListener(new View.OnFocusChangeListener() {
@Override
public void onFocusChange(View view, boolean b) {
if (b)
datePicker(view);
}
});
if (position != -1) {
fillTask(getTask(position));
button.setText("EDIT");
}
}