来自适配器的Intent数据后出错
当我尝试从适配器类加载数据意图时，我完全回到主要活动时遇到了这个问题
这是代码：
ToDoListAdapter：
public class ToDoListAdapter extends BaseAdapter {
private final List<ToDoItem> mItems = new ArrayList<ToDoItem>();
private final Context mContext;
private static final String TAG = "Lab-UserInterface";
public ToDoListAdapter(Context context) {
mContext = context;
}
// Add a ToDoItem to the adapter
// Notify observers that the data set has changed
public void add(ToDoItem item) {
mItems.add(item);
notifyDataSetChanged();
}
// Clears the list adapter of all items.
public void clear() {
mItems.clear();
notifyDataSetChanged();
}
// Returns the number of ToDoItems
@Override
public int getCount() {
return mItems.size();
}
// Retrieve the number of ToDoItems
@Override
public Object getItem(int pos) {
return mItems.get(pos);
}
// Get the ID for the ToDoItem
// In this case it's just the position
@Override
public long getItemId(int pos) {
return pos;
}
// Create a View for the ToDoItem at specified position
// Remember to check whether convertView holds an already allocated View
// before created a new View.
// Consider using the ViewHolder pattern to make scrolling more efficient
// See: http://developer.android.com/training/improving-layouts/smooth-scrolling.html
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO - Get the current ToDoItem
final ToDoItem toDoItem = (ToDoItem) getItem (position);
// TODO - Inflate the View for this ToDoItem
// from todo_item.xml
//RelativeLayout itemLayout = (RelativeLayout) convertView;
//convertView.inflate(mContext,R.layout.todo_item, null);
// TODO - Fill in specific ToDoItem data
// Remember that the data that goes in this View
// corresponds to the user interface elements defined
// in the layout file
if(convertView == null){
LayoutInflater inflater =(LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = inflater.inflate(R.layout.add_todo, null);
}
// TODO - Display Title in TextView
final TextView titleView = (TextView) convertView.findViewById(R.id.titleView);
titleView.setText(toDoItem.getTitle());
// TODO - Set up Status CheckBox
final CheckBox statusView = (CheckBox) convertView.findViewById(R.id.statusCheckBox);
statusView.setChecked(toDoItem.getStatus()==Status.DONE);
statusView.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
Log.i(TAG, "Entered onCheckedChanged()");
// TODO - set up an OnCheckedChangeListener, which
// is called when the user toggles the status checkbox
if (toDoItem.getStatus().equals(Status.DONE))
{
toDoItem.setStatus(Status.NOTDONE); //Change it
}
else
{
toDoItem.setStatus(Status.DONE); //Change it
}
}
});
// TODO - Display Priority in a TextView
final TextView priorityView = (TextView) convertView.findViewById(R.id.priorityView);
priorityView.setText(toDoItem.getPriority().toString());
// TODO - Display Time and Date.
// Hint - use ToDoItem.FORMAT.format(toDoItem.getDate()) to get date and
// time String
final TextView dateView = (TextView)convertView.findViewById(R.id.dateView);
dateView.setText(ToDoItem.FORMAT.format(toDoItem.getDate()));
}
// Return the View you just created
return convertView;
}
}
此代码适用于： ToDoManagerActivity（主要活动）：
public class ToDoManagerActivity extends ListActivity {
private static final int ADD_TODO_ITEM_REQUEST = 0;
private static final String FILE_NAME = "TodoManagerActivityData.txt";
private static final String TAG = "Lab-UserInterface";
// IDs for menu items
private static final int MENU_DELETE = Menu.FIRST;
private static final int MENU_DUMP = Menu.FIRST + 1;
ToDoListAdapter mAdapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Create a new TodoListAdapter for this ListActivity's ListView
mAdapter = new ToDoListAdapter(getApplicationContext());
// Put divider between ToDoItems and FooterView
getListView().setFooterDividersEnabled(true);
// TODO - Inflate footerView for footer_view.xml file
LayoutInflater inflator = LayoutInflater.from(ToDoManagerActivity.this);
TextView footerView = (TextView)inflator.inflate(R.layout.footer_view, null);
// TODO - Add footerView to ListView
getListView().addFooterView(footerView);
footerView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.i(TAG,"Entered footerView.OnClickListener.onClick()");
//TODO - Implement OnClick().
Intent toDoIntent = new Intent(getBaseContext(),AddToDoActivity.class);
startActivityForResult(toDoIntent, ADD_TODO_ITEM_REQUEST);
}
});
// TODO - Attach the adapter to this ListActivity's ListView
setListAdapter(mAdapter);
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
Log.i(TAG,"Entered onActivityResult()");
// TODO - Check result code and request code
// if user submitted a new ToDoItem
// Create a new ToDoItem from the data Intent
// and then add it to the adapter
if (requestCode == ADD_TODO_ITEM_REQUEST) {
if (resultCode == RESULT_OK)
{
ToDoItem toDo = new ToDoItem(data);
mAdapter.add(toDo);
}
else
{
}
}
}
// Do not modify below here
@Override
public void onResume() {
super.onResume();
// Load saved ToDoItems, if necessary
if (mAdapter.getCount() == 0)
loadItems();
}
@Override
protected void onPause() {
super.onPause();
// Save ToDoItems
saveItems();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
super.onCreateOptionsMenu(menu);
menu.add(Menu.NONE, MENU_DELETE, Menu.NONE, "Delete all");
menu.add(Menu.NONE, MENU_DUMP, Menu.NONE, "Dump to log");
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case MENU_DELETE:
mAdapter.clear();
return true;
case MENU_DUMP:
dump();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
private void dump() {
for (int i = 0; i < mAdapter.getCount(); i++) {
String data = ((ToDoItem) mAdapter.getItem(i)).toLog();
Log.i(TAG, "Item " + i + ": " + data.replace(ToDoItem.ITEM_SEP, ","));
}
}
// Load stored ToDoItems
private void loadItems() {
BufferedReader reader = null;
try {
FileInputStream fis = openFileInput(FILE_NAME);
reader = new BufferedReader(new InputStreamReader(fis));
String title = null;
String priority = null;
String status = null;
Date date = null;
while (null != (title = reader.readLine())) {
priority = reader.readLine();
status = reader.readLine();
date = ToDoItem.FORMAT.parse(reader.readLine());
mAdapter.add(new ToDoItem(title, Priority.valueOf(priority),
Status.valueOf(status), date));
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
} catch (ParseException e) {
e.printStackTrace();
} finally {
if (null != reader) {
try {
reader.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
}
// Save ToDoItems to file
private void saveItems() {
PrintWriter writer = null;
try {
FileOutputStream fos = openFileOutput(FILE_NAME, MODE_PRIVATE);
writer = new PrintWriter(new BufferedWriter(new OutputStreamWriter(
fos)));
for (int idx = 0; idx < mAdapter.getCount(); idx++) {
writer.println(mAdapter.getItem(idx));
}
} catch (IOException e) {
e.printStackTrace();
} finally {
if (null != writer) {
writer.close();
}
}
}
}
最后一个代码是：
AddToDoActivity（第二个活动）：
public class AddToDoActivity extends Activity {
// 7 days in milliseconds - 7 * 24 * 60 * 60 * 1000
private static final int SEVEN_DAYS = 604800000;
private static final String TAG = "Lab-UserInterface";
private static String timeString;
private static String dateString;
private static TextView dateView;
private static TextView timeView;
private Date mDate;
private RadioGroup mPriorityRadioGroup;
private RadioGroup mStatusRadioGroup;
private EditText mTitleText;
private RadioButton mDefaultStatusButton;
private RadioButton mDefaultPriorityButton;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.add_todo);
mTitleText = (EditText) findViewById(R.id.title);
mDefaultStatusButton = (RadioButton) findViewById(R.id.statusNotDone);
mDefaultPriorityButton = (RadioButton) findViewById(R.id.medPriority);
mPriorityRadioGroup = (RadioGroup) findViewById(R.id.priorityGroup);
mStatusRadioGroup = (RadioGroup) findViewById(R.id.statusGroup);
dateView = (TextView) findViewById(R.id.date);
timeView = (TextView) findViewById(R.id.time);
// Set the default date and time
setDefaultDateTime();
// OnClickListener for the Date button, calls showDatePickerDialog() to
// show
// the Date dialog
final Button datePickerButton = (Button) findViewById(R.id.date_picker_button);
datePickerButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
showDatePickerDialog();
}
});
// OnClickListener for the Time button, calls showTimePickerDialog() to
// show the Time Dialog
final Button timePickerButton = (Button) findViewById(R.id.time_picker_button);
timePickerButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
showTimePickerDialog();
}
});
// OnClickListener for the Cancel Button,
final Button cancelButton = (Button) findViewById(R.id.cancelButton);
cancelButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.i(TAG, "Entered cancelButton.OnClickListener.onClick()");
// TODO - Indicate result and finish
Intent returnIntent = new Intent();
setResult(RESULT_CANCELED,returnIntent);
finish();
}
});
// TODO - Set up OnClickListener for the Reset Button
final Button resetButton = (Button) findViewById(R.id.resetButton);
resetButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.i(TAG, "Entered resetButton.OnClickListener.onClick()");
// TODO - Reset data to default values
mTitleText.setText("");
setDefaultDateTime();
mDefaultStatusButton.setChecked(true);
mDefaultPriorityButton.setChecked(true);
}
});
// Set up OnClickListener for the Submit Button
final Button submitButton = (Button) findViewById(R.id.submitButton);
submitButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.i(TAG, "Entered submitButton.OnClickListener.onClick()");
// gather ToDoItem data
// TODO - Get the current Priority
Priority priority = getPriority();
// TODO - Get the current Status
Status status = getStatus();
// TODO - Get the current ToDoItem Title
String titleString = getToDoTitle();
// Construct the Date string
String fullDate = dateString + " " + timeString;
// Package ToDoItem data into an Intent
Intent data = new Intent();
ToDoItem.packageIntent(data, titleString, priority, status,
fullDate);
setResult(Activity.RESULT_OK,data);
finish();
// TODO - return data Intent and finish
}
});
}
// Do not modify below this point.
private void setDefaultDateTime() {
// Default is current time + 7 days
mDate = new Date();
mDate = new Date(mDate.getTime() + SEVEN_DAYS);
Calendar c = Calendar.getInstance();
c.setTime(mDate);
setDateString(c.get(Calendar.YEAR), c.get(Calendar.MONTH),
c.get(Calendar.DAY_OF_MONTH));
dateView.setText(dateString);
setTimeString(c.get(Calendar.HOUR_OF_DAY), c.get(Calendar.MINUTE),
c.get(Calendar.MILLISECOND));
timeView.setText(timeString);
}
private static void setDateString(int year, int monthOfYear, int dayOfMonth) {
// Increment monthOfYear for Calendar/Date -> Time Format setting
monthOfYear++;
String mon = "" + monthOfYear;
String day = "" + dayOfMonth;
if (monthOfYear < 10)
mon = "0" + monthOfYear;
if (dayOfMonth < 10)
day = "0" + dayOfMonth;
dateString = year + "-" + mon + "-" + day;
}
private static void setTimeString(int hourOfDay, int minute, int mili) {
String hour = "" + hourOfDay;
String min = "" + minute;
if (hourOfDay < 10)
hour = "0" + hourOfDay;
if (minute < 10)
min = "0" + minute;
timeString = hour + ":" + min + ":00";
}
private Priority getPriority() {
switch (mPriorityRadioGroup.getCheckedRadioButtonId()) {
case R.id.lowPriority: {
return Priority.LOW;
}
case R.id.highPriority: {
return Priority.HIGH;
}
default: {
return Priority.MED;
}
}
}
private Status getStatus() {
switch (mStatusRadioGroup.getCheckedRadioButtonId()) {
case R.id.statusDone: {
return Status.DONE;
}
default: {
return Status.NOTDONE;
}
}
}
private String getToDoTitle() {
return mTitleText.getText().toString();
}
// DialogFragment used to pick a ToDoItem deadline date
public static class DatePickerFragment extends DialogFragment implements
DatePickerDialog.OnDateSetListener {
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
// Use the current date as the default date in the picker
final Calendar c = Calendar.getInstance();
int year = c.get(Calendar.YEAR);
int month = c.get(Calendar.MONTH);
int day = c.get(Calendar.DAY_OF_MONTH);
// Create a new instance of DatePickerDialog and return it
return new DatePickerDialog(getActivity(), this, year, month, day);
}
@Override
public void onDateSet(DatePicker view, int year, int monthOfYear,
int dayOfMonth) {
setDateString(year, monthOfYear, dayOfMonth);
dateView.setText(dateString);
}
}
// DialogFragment used to pick a ToDoItem deadline time
public static class TimePickerFragment extends DialogFragment implements
TimePickerDialog.OnTimeSetListener {
@Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
// Use the current time as the default values for the picker
final Calendar c = Calendar.getInstance();
int hour = c.get(Calendar.HOUR_OF_DAY);
int minute = c.get(Calendar.MINUTE);
// Create a new instance of TimePickerDialog and return
return new TimePickerDialog(getActivity(), this, hour, minute, true);
}
public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
setTimeString(hourOfDay, minute, 0);
timeView.setText(timeString);
}
}
private void showDatePickerDialog() {
DialogFragment newFragment = new DatePickerFragment();
newFragment.show(getFragmentManager(), "datePicker");
}
private void showTimePickerDialog() {
DialogFragment newFragment = new TimePickerFragment();
newFragment.show(getFragmentManager(), "timePicker");
}
}
这是logcat中出现的错误：
2 个答案:
答案 0 :(得分：0)
正如LogCat输出提示的那样，检索正确的视图存在问题。更详细地说，您必须尝试从不包含它的布局定义中获取TitleView组件等项目。意思是，问题应该存在于这一行：
convertView = inflater.inflate(R.layout.add_todo, null);
确保add_todo是正确的布局，并且它包含您尝试从中获取的组件
答案 1 :(得分：0)
应该是：
convertView = inflater.inflate(R.layout.todo_item, null);
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