SimpleDateFormat和错误的日期
我已经尝试了下面的前两个建议，但我再次尝试并衷心感谢您的帮助！ 结果虽然相同。 我将编辑帖子以添加更多代码信息。
你好！ 我正在试验一个简单的ToDo应用程序，并设法改变我想要的几乎所有东西，除了用户保存任务后显示的日期格式。
该任务本身通过具有以下恢复代码的AddToDoActivity类添加：
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("Entered cancelButton.OnClickListener.onClick()");
finish();
}
});
//OnClickListener for the Reset Button
final Button resetButton = (Button) findViewById(R.id.resetButton);
resetButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
log("Entered resetButton.OnClickListener.onClick()");
setDefaultDateTime();
mTitleText.setText("");
mDefaultStatusButton.setChecked(true);
mDefaultPriorityButton.setChecked(true);
}
});
// OnClickListener for the Submit Button
// Implement onClick().
final Button submitButton = (Button) findViewById(R.id.submitButton);
submitButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
log("Entered submitButton.OnClickListener.onClick()");
// Gather ToDoItem data
Priority priority = getPriority();
Status status = getStatus();
String titleString = mTitleText.getText().toString();
// Date
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();
}
});
}
// Do not modify below here
// Use this method to set the default date and time
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.DAY_OF_MONTH), c.get(Calendar.MONTH),
c.get(Calendar.YEAR));
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 dayOfMonth, int monthOfYear, int year) {
// 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;
}
}
}
// 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 day = c.get(Calendar.DAY_OF_MONTH);
int month = c.get(Calendar.MONTH);
int year = c.get(Calendar.YEAR);
// Create a new instance of DatePickerDialog and return it
return new DatePickerDialog(getActivity(), this, year, month, day);
}
@Override
public void onDateSet(DatePicker view, int dayOfMonth, int monthOfYear,
int year) {
setDateString(dayOfMonth, monthOfYear, year);
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");
}
private void log(String msg) {
try {
Thread.sleep(500);
} catch (InterruptedException e) {
e.printStackTrace();
}
Log.i(TAG, msg);
}
}
这里是ToDoItem，它实际上从AddToDoActivity中读取信息：
public class ToDoItem {
public static final String ITEM_SEP = System.getProperty("line.separator");
public enum Priority {
LOW, MED, HIGH
};
public enum Status {
NOTDONE, DONE
};
public final static String TITLE = "title";
public final static String PRIORITY = "priority";
public final static String STATUS = "status";
public final static String DATE = "date";
public final static String FILENAME = "filename";
public final static SimpleDateFormat FORMAT = new SimpleDateFormat(
"dd/MM/yyyy HH:mm:ss", Locale.US);
private String mTitle = new String();
private Priority mPriority = Priority.LOW;
private Status mStatus = Status.NOTDONE;
private Date mDate = new Date();
ToDoItem(String title, Priority priority, Status status, Date date) {
this.mTitle = title;
this.mPriority = priority;
this.mStatus = status;
this.mDate = date;
}
// Create a new ToDoItem from data packaged in an Intent
ToDoItem(Intent intent) {
mTitle = intent.getStringExtra(ToDoItem.TITLE);
mPriority = Priority.valueOf(intent.getStringExtra(ToDoItem.PRIORITY));
mStatus = Status.valueOf(intent.getStringExtra(ToDoItem.STATUS));
try {
mDate = ToDoItem.FORMAT.parse(intent.getStringExtra(ToDoItem.DATE));
} catch (ParseException e) {
mDate = new Date();
}
}
public String getTitle() {
return mTitle;
}
public void setTitle(String title) {
mTitle = title;
}
public Priority getPriority() {
return mPriority;
}
public void setPriority(Priority priority) {
mPriority = priority;
}
public Status getStatus() {
return mStatus;
}
public void setStatus(Status status) {
mStatus = status;
}
public Date getDate() {
return mDate;
}
public void setDate(Date date) {
mDate = date;
}
// Take a set of String data values and
// package them for transport in an Intent
public static void packageIntent(Intent intent, String title,
Priority priority, Status status, String date) {
intent.putExtra(ToDoItem.TITLE, title);
intent.putExtra(ToDoItem.PRIORITY, priority.toString());
intent.putExtra(ToDoItem.STATUS, status.toString());
intent.putExtra(ToDoItem.DATE, date);
}
public String toString() {
return mTitle + ITEM_SEP + mPriority + ITEM_SEP + mStatus + ITEM_SEP
+ FORMAT.format(mDate);
}
public String toLog() {
return "Title:" + mTitle + ITEM_SEP + "Priority:" + mPriority
+ ITEM_SEP + "Status:" + mStatus + ITEM_SEP + "Date:"
+ FORMAT.format(mDate);
}
}
噢，经过几小时的调整，“公共最终静态SimpleDateFormat FORMAT =新的SimpleDateFormat（”yyyy-MM-dd HH：mm：ss“，Locale.US）;” 方法从ToDoItem，我仍然无法成功地将yyyy-MM-dd转换为dd / MM / yyyy。
首先，我尝试了很明显的做法，并将表达式yyyy-MM-dd更改为dd / MM / yyyy。
在此之后，即使在AddToDoActivity上输入的日期比预计要好几个月或几年，我在保存任务后得到的所有内容都是今天的日期。
如果我恢复为yyyy-MM-dd，任务列表中显示的日期与AddToDoActivity上输入的日期相同。
然后，我尝试改变每个班级的所有日期以匹配我想要的确切格式。
这使得AddToDoActivity上的所有内容都看起来不错，但是当我将日期传回ToDoItem时，应用程序只是忽略了之前输入的日期，并再次显示了今天的日期。
任何人都可以帮助我这个？
谢谢！！
您按照年，月，日的顺序使用参数调用setDateString ：
setDateString(c.get(Calendar.YEAR), c.get(Calendar.MONTH),
c.get(Calendar.DAY_OF_MONTH));
但是你的方法按照日，月，年的顺序有参数：
private static void setDateString(int dayOfMonth, int monthOfYear, int year) {
...
}
我还认为在将代码复制到问题中时出现了一些错误，因为setDateString方法是重复的，并且没有setTimeString方法。
更改：
setDateString(c.get(Calendar.YEAR), c.get(Calendar.MONTH), c.get(Calendar.DAY_OF_MONTH));
至：
setDateString(c.get(Calendar.DAY_OF_MONTH), c.get(Calendar.MONTH), c.get(Calendar.YEAR));
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