CODEWITHSUNDEEP
javaandroid-studio
Shimrit Hadadi
Shimrit Hadadi

Reputation: 115

How do i make a new instance for a new class code i created?

This is the new class code:

package com.test.webservertest;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import java.util.Timer;

/**
 * Created by tester on 8/27/2015.
 */

public class TimerCounter extends Activity
{

    TextView timerTextView;
    long startTime = 0;

    Handler timerHandler = new Handler();
    Runnable timerRunnable = new Runnable() {

        @Override
        public void run() {
            long millis = System.currentTimeMillis() - startTime;
            int seconds = (int) (millis / 1000);
            int minutes = seconds / 60;
            seconds = seconds % 60;

            timerTextView.setText(String.format("%d:%02d", minutes, seconds));

            timerHandler.postDelayed(this, 500);
        }
    };

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

        timerTextView = (TextView) findViewById(R.id.textView3);

        Button b = (Button) findViewById(R.id.button);
        b.setText("start");
        b.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View v) {
                Button b = (Button) v;
                if (b.getText().equals("stop")) {
                    timerHandler.removeCallbacks(timerRunnable);
                    b.setText("start");
                } else {
                    startTime = System.currentTimeMillis();
                    timerHandler.postDelayed(timerRunnable, 0);
                    b.setText("stop");
                }
            }
        });
    }

    @Override
    public void onPause() {
        super.onPause();
        timerHandler.removeCallbacks(timerRunnable);
        Button b = (Button)findViewById(R.id.button);
        b.setText("start");
    }

}

And in the MainActivity.java file in the onCreate i did:

private TimerCounter tc;

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tc = new TimerCounter();
        tc.onCreate(savedInstanceState);
    }

Now when running the program i'm getting exception in the TimerCounter class on the line:

super.onCreate(savedInstanceState);

savedInstanceState null

What i want to do is either using the button in the TimerCounter class or without the button when running my program the timer will start.

How can i do it using the button and without the button ?

I added to the MainActivity designer a button and a textView3

Upvotes: 1

Views: 49

Answers (1)

sista_melody
sista_melody

Reputation: 49

  • For using a button to start and stop timer: there is this nice android example.
  • For doing this without the button: you cut the code inside onClick(View view) and paste it directly in onCreate(Bundle savedInstance).

Upvotes: 2

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