我正在开发一个我有两个日期选择器的应用程序。如何计算这些日期选择器选择的日期之间的天数？是否有图书馆或内置功能？
以下是我的代码：
public class ApplyLeave extends AppCompatActivity {
private static final String tag = "ApplyLeave";
private TextView fomDate;
private TextView ToDate, days_count;
private EditText reason;
private Button save_btn, apply_btn, select_recepeints;
private TextView leave_type;
private DatePickerDialog.OnDateSetListener fromdatelistener;
private DatePickerDialog.OnDateSetListener todatelistener;
String date1, date2;
int day1, day2;
Spinner spinner;
ArrayAdapter<CharSequence> adapter;
ListView lv;
@RequiresApi(api = Build.VERSION_CODES.N)
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_apply_leave);
reason=(EditText)findViewById(R.id.reason);
fomDate=(TextView)findViewById(R.id.from_date);
days_count=(TextView)findViewById(R.id.Days_count);
ToDate=(TextView)findViewById(R.id.to_date);
leave_type=(TextView)findViewById(R.id.leave_type);
save_btn=(Button)findViewById(R.id.save_button);
apply_btn=(Button)findViewById(R.id.apply_button);
select_recepeints=(Button)findViewById(R.id.edit_rec);
lv = (ListView)findViewById(R.id.result);
final FragmentManager fm=getFragmentManager();
final edit_recepients er=new edit_recepients();
select_recepeints.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
er.show(fm,"TV_tag");
}
});
SharedPreferences sharedPreferences =getSharedPreferences("MyData",MODE_PRIVATE);
String leave_typ= sharedPreferences.getString("leave_type","null");
String formdate= sharedPreferences.getString("fromDate","null");
String toDate= sharedPreferences.getString("ToDate","null");
String reson= sharedPreferences.getString("reason","null");
String recepienst= sharedPreferences.getString("recepients","null");
if(leave_typ.equals("null") || formdate.equals("null") || toDate.equals("null") || reson.equals("null"))
{
Toast.makeText(getApplicationContext(), "not data found",Toast.LENGTH_SHORT).show();
}
else {
leave_type.setText(leave_typ);
fomDate.setText(formdate);
ToDate.setText(toDate);
reason.setText(reson);
}
save_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
SharedPreferences sharedPreferences=getApplicationContext().getSharedPreferences("MyData",MODE_PRIVATE);
SharedPreferences.Editor editor=sharedPreferences.edit();
editor.putString("leave_type",leave_type.getText().toString());
editor.putString("fromDate",fomDate.getText().toString());
editor.putString("ToDate",ToDate.getText().toString());
editor.putString("reason",reason.getText().toString());
editor.putString("recepients",lv.getAdapter().toString());
editor.commit();
Toast.makeText(getApplicationContext(),"Application saved",Toast.LENGTH_SHORT).show();
}
});
//spinner for leave
spinner=(Spinner)findViewById(R.id.leaves);
adapter=ArrayAdapter.createFromResource(this,R.array.leave_type,R.layout.spinner_layout);
adapter.setDropDownViewResource(R.layout.support_simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
//get data from dashboard activity and set into spineer
spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
if(getIntent().getExtras()!=null) {
int select = getIntent().getExtras().getInt("leave");
spinner.setSelection(select);
}
}
@Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
//listview to display selected persons on Apply leave Acitivity from the onclick event on setttings activiy.
if(getIntent().getExtras()!=null) {
Bundle b = getIntent().getExtras();
String[] resultArr = b.getStringArray("selectedItems");
ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
R.layout.spinner_layout, resultArr);
lv.setAdapter(adapter);
}
//
// Back button in toolbar
Toolbar toolbar = (Toolbar)findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
toolbar.setTitleTextColor(getResources().getColor(R.color.o2htextOne));
getSupportActionBar().setDisplayShowTitleEnabled(false);
final Drawable upArrow = getResources().getDrawable(R.drawable.back_arrow);
upArrow.setColorFilter(getResources().getColor(R.color.o2htextOne), PorterDuff.Mode.SRC_ATOP);
getSupportActionBar().setHomeAsUpIndicator(upArrow);
if(getSupportActionBar()!=null)
{
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}//
fomDate.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.N)
@Override
public void onClick(View v) {
Calendar calendar= Calendar.getInstance();
int year=calendar.get(Calendar.YEAR);
int month=calendar.get(Calendar.MONTH);
int day=calendar.get(Calendar.DAY_OF_MONTH);
day1=calendar.get(Calendar.DAY_OF_YEAR);
DatePickerDialog datePickerDialog=new DatePickerDialog(ApplyLeave.this,
R.style.DatePickerDialogTheme,
fromdatelistener,year,month,day);
datePickerDialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.WHITE));
datePickerDialog.show();
}
});
fromdatelistener= new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
month=month+1;
Log.d("tag","setDate: "+year+ "/"+month+"/"+dayOfMonth+"");
date1 =+year+ "/"+month+"/"+dayOfMonth+"";
fomDate.setText(date1);
}
};
ToDate.setOnClickListener(new View.OnClickListener() {
@RequiresApi(api = Build.VERSION_CODES.N)
@Override
public void onClick(View v) {
Calendar calendar= Calendar.getInstance();
int year=calendar.get(Calendar.YEAR);
int month=calendar.get(Calendar.MONTH);
int day=calendar.get(Calendar.DAY_OF_MONTH);
day2=calendar.get(Calendar.DAY_OF_YEAR);
DatePickerDialog datePickerDialog=new DatePickerDialog(ApplyLeave.this,
R.style.DatePickerDialogTheme,
todatelistener,year,month,day);
datePickerDialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.WHITE));
datePickerDialog.show();
}
});
todatelistener= new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
month=month+1;
Log.d("tag","setDate: "+year+ "/"+month+"/"+dayOfMonth+"");
date2 =+year+ "/"+month+"/"+dayOfMonth+"";
ToDate.setText(date2);
}
};
}
@Override
public void onBackPressed() {
Intent intent = new Intent(getApplicationContext(), Main3Activity.class);
intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
if(item.getItemId()==android.R.id.home)
{
finish();
}
return super.onOptionsItemSelected(item);
}
}
答案 0 :(得分：0)
你可以做的只是：
像这样的2个日期 -
Date date1,date2;
//Difference in milliseconds:
long difference = date2.getTime()-date1.getTime();
然后您可以简单地将毫秒转换为小时，秒和日期。
希望这有帮助。
答案 1 :(得分：0)
要获得日期差异，首先需要使用date_from减去date_to 像这样 -
long difference = Math.abs(date_to.getTime() - date_from.getTime());
然后你可以用下面给出的公式得到天差 -
int days = (int) (difference / (1000 * 60 * 60 * 24));
答案 2 :(得分：0)
使用getUnitBetweenDates尝试此操作，您可以计算日期之间没有天数
SimpleDateFormat dfDate = new SimpleDateFormat("yyyy-MM-dd");
java.util.Date d = null;
java.util.Date d1 = null;
try {
d = dfDate.parse(2017-08-15);
d1 = dfDate.parse(2017-08-27);
} catch (java.text.ParseException e) {
e.printStackTrace();
}
long days = getUnitBetweenDates(d, d1, TimeUnit.DAYS);
Log.e("Days:-> ", days + "");
答案 3 :(得分：0)
找到解决方案
如果你的日期是字符串格式
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
Calendar c= Calendar.getInstance();
Date c= df.parse("YourStartDate");
String startDte = df.format(c.getTime());
Date startTime = df.parse(startDte);
c.setTime(startTime);
long startDateinMillis = c.getTime();
Date c= df.parse("YourEndDate");
String endDt= df.format(c.getTime());
Date endTime= df.parse(endDt);
c.setTime(endTime);
long endDateInMillis = c.getTime();
long different = endDateInMillis - startDateinMillis;
long daysInMilli = hoursInMilli * 24;
long elapsedDays = different / daysInMilli;
System.out.printf("%d days, elapsedDays);
如果您的日期格式为日期：
long different = endDate.getTimeInMillis() - startDate.getTimeInMillis();
long daysInMilli = hoursInMilli * 24;
long elapsedDays = different / daysInMilli;
System.out.printf("%d days, elapsedDays);
答案 4 :(得分：0)
以下是计算两个日期之间差异的方法：
PS：fromDate和toDate是Date类的实例。
long diffInMillies = fromDate.getTime() - toDate.getTime();
int diffInDays = (int) TimeUnit.DAYS.convert(diffInMillies, TimeUnit.MILLISECONDS);
以下是使用上述代码的示例类：
public class TestClass extends AppCompatActivity {
private DatePickerDialog.OnDateSetListener fromDateListener;
private DatePickerDialog.OnDateSetListener toDateListener;
private TextView fromDateView, toDateView;
private Date fromDate, toDate;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.test_class);
fromDateView = (TextView) findViewById(R.id.fromDateView);
toDateView = (TextView) findViewById(R.id.toDateView);
Button button = (Button) findViewById(R.id.button);
final SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd", Locale.US);
fromDateView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Calendar calendar = Calendar.getInstance();
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH);
int day = calendar.get(Calendar.DAY_OF_MONTH);
DatePickerDialog dialog = new DatePickerDialog(
TestClass.this,
R.style.DatePickerDialogTheme,
fromDateListener, year, month, day);
dialog.show();
}
});
toDateView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Calendar calendar = Calendar.getInstance();
int year = calendar.get(Calendar.YEAR);
int month = calendar.get(Calendar.MONTH);
int day = calendar.get(Calendar.DAY_OF_MONTH);
DatePickerDialog dialog = new DatePickerDialog(
TestClass.this,
R.style.DatePickerDialogTheme,
toDateListener, year, month, day);
dialog.show();
}
});
button.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (fromDate == null || toDate == null) return;
long diffInMillies = fromDate.getTime() - toDate.getTime();
int diffInDays = (int) TimeUnit.DAYS.convert(diffInMillies, TimeUnit.MILLISECONDS);
Log.d("Difference in days", String.valueOf(diffInDays));
}
});
fromDateListener = new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.YEAR, year);
calendar.set(Calendar.MONTH, month);
calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
fromDate = calendar.getTime();
fromDateView.setText(dateFormat.format(fromDate));
}
};
toDateListener = new DatePickerDialog.OnDateSetListener() {
@Override
public void onDateSet(DatePicker view, int year, int month, int dayOfMonth) {
Calendar calendar = Calendar.getInstance();
calendar.set(Calendar.YEAR, year);
calendar.set(Calendar.MONTH, month);
calendar.set(Calendar.DAY_OF_MONTH, dayOfMonth);
toDate = calendar.getTime();
toDateView.setText(dateFormat.format(toDate));
}
};
}
}