如何在android中计算两个时间选择器之间的时间差

Question

我可以找出两个时间间隔之间的差异，但当第一个时间是凌晨12:00或00:00时，第二个时间是任何其他时间时，我无法得到准确的差异。相反，我得到了一个负面的差异。经过调试，我发现时间实际上是1970年1月。我无法用今天的时间来纠正它并计算差额。

package com.cksapp.memoryin;
import androidx.appcompat.app.AppCompatActivity;
import android.app.TimePickerDialog;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.TimePicker;
import android.widget.Toast;
import com.google.firebase.Timestamp;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.firestore.FirebaseFirestoreSettings;
import java.security.CodeSigner;
import java.sql.Time;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
//import java.util.Date;
public class HourlyCalculator extends AppCompatActivity {
EditText wage;
TextView t1, t2, t3;
ImageView i1, i2;
Button b1;
int minutestotal;
String timex, timey;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.calculator_hourly);
wage = findViewById(R.id.hourlyrate);
t1 = findViewById(R.id.starttimetext);
t2 = findViewById(R.id.endtimetext);
t3 = findViewById(R.id.finaltime);
i1 = findViewById(R.id.startimage);
i2 = findViewById(R.id.endimage);
b1 = findViewById(R.id.calculatebutton);

Calendar c = Calendar.getInstance();
final int hour = c.get(Calendar.HOUR_OF_DAY);
final int mins = c.get(Calendar.MINUTE);
i1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final TimePickerDialog time = new TimePickerDialog(HourlyCalculator.this, new TimePickerDialog.OnTimeSetListener() {
@Override
public void onTimeSet(TimePicker view, int hourOfDay1, int minute1) {
timex = hourOfDay1 + ":" + minute1;
t1.setText(timex);
Log.d("Time1", timex);
}
},hour, mins, true);
time.show();
}
});
i2.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
final TimePickerDialog time2 = new TimePickerDialog(HourlyCalculator.this, new TimePickerDialog.OnTimeSetListener() {
@Override
public void onTimeSet(TimePicker view, int hourOfDay, int minute) {
timey = hourOfDay + ":" + minute;
t2.setText(timey);
Log.d("Time1", timey);
}
},hour,mins,true);
time2.show();
}
});
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
SimpleDateFormat sdf = new SimpleDateFormat("HH:mm");
try {
Date a = sdf.parse(timex);
Date b = sdf.parse(timey);
long difference = a.getTime() - b.getTime();
Log.d("Time", String.valueOf(difference));
/* minutestotal = (int) (difference/60000);
Log.d("Timearey", String.valueOf(minutestotal));
int totalwageinitital = Integer.parseInt(wage.getText().toString());
double totalwagepermin = totalwageinitital/60;
double finalprice = minutestotal * totalwagepermin;
t3.setText(String.valueOf(finalprice));*/
} catch (ParseException e) {
e.printStackTrace();
}
}
});
}
}

Answer 1

您只使用小时和分钟来解析时间，而没有提供sdf假设的1970年1月1日的年份、月份和日期。

你应该用不同的方式来完成这项工作：使用calendar.getInstance((为每个日期初始化一个日历对象，这将为你提供一个包含今天日期的实例，然后根据选择器中的小时和分钟设置这两个实例的小时和分钟，并检查它们之间的时间差InMilliseconds。

Calendar time = Calendar.getInstance();
time.set(Calendar.HOUR_OF_DAY, hour);
time.set(Calendar.MINUTE, minute);