How to show the live DateTime as a textView (Like a digital watch) in Android Studio?-CodePudding

I have made two textView in an xml file where one textView shows current date and another shows current time as text.

Now, I have used the java Calendar.getInstance().getTime() method to get the date & time information. But it is acting as a static view i.e. it is not changing the date & time like a digital clock.

Now I am trying to show the textViews to show the current date & time in synchronization with device-system's date & time. That means, suppose now it is 11:59:59 PM in the night and the date is 7th Sep, 2022. Just after 1s, my time textView should show the time as 12:00:00 AM and date should show as 8th Sep, 2022. And it should continue to change the time after every 1s like a digital clock. Last of all, there should not be any delay in between system dateTime & app dateTime i.e. perfectly synchronised.

How to do that??

public class MainActivity extends AppCompatActivity {

    TextView textDate, textClock;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        textDate = findViewById(R.id.textDate);
        textClock = findViewById(R.id.textClock);
        setDateTime();
    }

    private void setDateTime() {
        Date c = Calendar.getInstance().getTime();
        SimpleDateFormat df = new SimpleDateFormat("dd MMM, yyyy", Locale.getDefault());
        SimpleDateFormat df_clock = new SimpleDateFormat("hh:mm:ss a", Locale.getDefault());
        String formattedDate = df.format(c);
        String formattedClock = df_clock.format(c);

        textDate.setText(formattedDate);
        textClock.setText(formattedClock);
    }
}

CodePudding user response：

There's already a TextClock class in Android which you should be able to use. Try replacing your two TextViews with these and set the formats to your patterns.

CodePudding user response：

You need to set up a background thread that will ask the UI to update itself every second.

I think something like this (but I don't know how accurate this will be)

private void blink() {
      final Handler hander = new Handler();
      new Thread(new Runnable() {
         @Override
         public void run() {
            // off the UI
            try {
               Thread.sleep(1000);
            } catch (InterruptedException e) {
               e.printStackTrace();
            }
            // back ot the UI
            hander.post(new Runnable() {
               @Override
               public void run() {
                  // notify the UI here
                  blink();
               }
            });
         }
      }).start();
   }