嗨，我在三个以上的类中使用日期选择器并具有相同的验证。相反，我必须在一个类中编写并在需要时在其他类中调用该函数，是否可以在日期选择器的代码下方。
public class MainActivity extends Activity {
private TextView tvDisplayDate;
private Button btnChangeDate;
private int myear;
private int mmonth;
private int mday;
static final int DATE_DIALOG_ID = 999;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setCurrentDateOnView();
addListenerOnButton();
}
// display current date
public void setCurrentDateOnView() {
tvDisplayDate = (TextView) findViewById(R.id.tvDate);
final Calendar c = Calendar.getInstance();
myear = c.get(Calendar.YEAR);
mmonth = c.get(Calendar.MONTH);
mday = c.get(Calendar.DAY_OF_MONTH);
// set current date into textview
tvDisplayDate.setText(new StringBuilder()
// Month is 0 based, just add 1
.append(mmonth + 1).append("-").append(mday).append("-")
.append(myear).append(" "));
}
public void addListenerOnButton() {
btnChangeDate = (Button) findViewById(R.id.btnChangeDate);
btnChangeDate.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
showDialog(DATE_DIALOG_ID);
}
});
}
@Override
protected Dialog onCreateDialog(int id) {
switch (id) {
case DATE_DIALOG_ID:
// set date picker as current date
DatePickerDialog _date = new DatePickerDialog(this, datePickerListener, myear,mmonth,
mday)
{
@Override
public void onDateChanged(DatePicker view, int year, int monthOfYear, int dayOfMonth)
{
if (year < myear)
view.updateDate(myear, mmonth, mday);
if (monthOfYear < mmonth && year == myear)
view.updateDate(myear, mmonth, mday);
if (dayOfMonth < mday && year == myear && monthOfYear == mmonth)
view.updateDate(myear, mmonth, mday);
}
};
return _date;
}
return null;
}
private DatePickerDialog.OnDateSetListener datePickerListener = new DatePickerDialog.OnDateSetListener() {
// when dialog box is closed, below method will be called.
public void onDateSet(DatePicker view, int selectedYear,
int selectedMonth, int selectedDay) {
myear = selectedYear;
mmonth = selectedMonth;
mday = selectedDay;
// set selected date into textview
tvDisplayDate.setText(new StringBuilder().append(mmonth + 1)
.append("-").append(mday).append("-").append(myear)
.append(" "));
Date dateObject1 = new Date(myear - 1900, mmonth, mday);
Date dateObj2 = new Date(System.currentTimeMillis());
if(dateObject1.before(dateObj2) || dateObject1.equals(dateObj2)){
//the program runs normally
}
else{
new AlertDialog.Builder(MainActivity.this)
.setTitle("Wrong Data Input!")
.setMessage("The end Date must be Before the start Date, please insert new Date values")
.setNeutralButton("Ok",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int which) {
}
}).show();
}
}
};
}