为什么不在Android Studio中显示progressBar？

Question

I was trying to work with Progressbar in android studio. What I wanted was simply that when I will click on the button of the MainActivity it will intent to a new activity called 'Progress'. My activities are here:

MainActivity.java :

and Progress.java :

My app runs, but not showing any progressbar motion. What should I do to show progressbar for 30 sec? I am not doing anything in the meantime. I just want to see a progressbar for 30 sec.

Answer 1

1000 is too small for loop but this code do what you want :

//Set visible progres bar
findViewById(R.id.progress_bar).setVisibility(View.VISIBLE);

        //Timer in your case 30 sek
        int timer = 30*1000;

        //create handler
        final Handler handler = new Handler();

        //set handler delayed                
        handler.postDelayed(new Runnable() {
            @Override
            public void run() { 

        //Hidden progress bar
        findViewById(R.id.progress_bar).setVisibility(View.INVISIBLE);

        //your toast
        Toast.makeText(this,"your msg",Toast.LENGTH_LONG).show();

        //start new activity
        startActivity(your intent)
          }
        }, timer);
    }

Answer 2

mPrograssStatus is increasing to 100 in very short amount of time. You need to wait, for example try adding this to your code in loop while:

SystemClock.sleep(300);

value in brackets is amount of milliseconds that system will wait, in your case it is 300 to get 30 seconds. You also need to import library:

import android.os.SystemClock;