java - 在android studio中计算两次之间的差异

Question

1. 我创建了按钮来显示开始和停止停车的当前时间及其工作。

2. 但是当我点击deductbtn时，手机上的应用程序会弹出并显示“我的应用程序1已停止”

3. 我怎样才能解决这个问题？任何帮助都会非常有用。

   @Override
   protected void onCreate(final Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_payment_info);
   
   firebaseAuth = FirebaseAuth.getInstance();
   parkBtn = (Button)findViewById(R.id.parkBtn);
   stopparkBtn = (Button)findViewById(R.id.stopparkBtn);
   deductBtn = (Button)findViewById(R.id.deductBtn);
   timeResult = (TextView)findViewById(R.id.timeResult);
   timeResult2 = (TextView)findViewById(R.id.timeResult2);
   diffResult = (TextView)findViewById(R.id.diffResult);
   
   
   parkBtn.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View view) {
           final Date d = new Date();
           SimpleDateFormat sdf1=new SimpleDateFormat("hh:mm a");
           final String currentDateTimeString = sdf1.format(d);
           timeResult.setText(currentDateTimeString);
   
       }
   });
   
   stopparkBtn.setOnClickListener(new View.OnClickListener() {
       @Override
       public void onClick(View view) {
           final Date d1= new Date();
           SimpleDateFormat sdf2 = new SimpleDateFormat("hh:mm a");
           final String currentDateTimeString1 = sdf2.format(d1);
           timeResult2.setText(currentDateTimeString1);
   
   
       }
   });
   
   deductBtn.setOnClickListener(new View.OnClickListener() {
   
       @Override
       public void onClick(View view) {
   
           float totalTime = Float.parseFloat(timeResult2.getText().toString());
           float totalTime1 = Float.parseFloat(timeResult.getText().toString());
           final float timeUsage = totalTime - totalTime1;
           diffResult.setText(String.valueOf(timeUsage));
   
       }
   });
   
   }
   
   }
   

标签： javaandroid

Answer 1

新代码在这里：@Override public void onClick(View view) {

            SimpleDateFormat simpleDateFormat = new SimpleDateFormat("HH:mm a");
            Date date1 = null;
            try {
                date1 = simpleDateFormat.parse(timeResult.getText().toString());
            } catch (ParseException e) {
                e.printStackTrace();
            }
            Date date2 = null;
            try {
                date2 = simpleDateFormat.parse(timeResult2.getText().toString());
            } catch (ParseException e) {
                e.printStackTrace();
            }
            String diffResult= DateUtils.getRelativeTimeSpanString(date1.getTime(), date2.getTime(), DateUtils.FORMAT_SHOW_TIME).toString();
            deductBtn.setText(diffResult);
        }