Question

I’m kind of new when it comes to Android Application development and I’m developing an app at the moment. I’m trying to get my TextView change every time the user clicks the Button(NEXT) and when another Button (PREVIOUS) gets clicked on I want it to change back to the original TextView. So basically I’d like to set up a certain amount of TextViews and be able to browse through them with the two Buttons I mentioned.

So far I only know how to make the the TextView change one time on a Button(NEXT) click. I’m using this piece of code for that:

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

    ImageButton Next = (ImageButton) findViewById(R.id.Next);
    Next.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            TextView Text1= (TextView) findViewById(R.id.Text1);
            Text1.setText("New Text");  
        }
    });

NOTE: The Button “PREVIOUS” isn’t included yet because I didn’t know what to do with it yet.

I’m getting the feeling this code is only used when you want the TextView to change one time and you need a whole different method to make it change multiple times.

I hope I provided you with enough information and you are willing to help me out here.
Thanks in advance!

Answer 1

public class MyActivity extends Activity implements View.OnClickListener {

int stringIdList[] = {R.string.text1, R.string.text2, R.string.text3, R.string.text4}
int stringListCounter = 0;
TextView text1;

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

   ImageButton next = (ImageButton) findViewById(R.id.Next);
   ImageButton previous = (ImageButton) findViewById(R.id.Previous);
   text1 = (TextView) findViewById(R.id.Text1);
   Next.setOnClickListener(this);
   previous.setOnClickListener(this);
}

@Override
public void onClick(View v) {
  int id = v.getId();

  if(id == R.id.Next && stringListCounter < stringIdList.length - 1) {
    stringListCounter++;
  } else if (id == R.id.Previous && counter > 0) {
    stringListCounter--;
  }

  Text1.setText(stringIdList[stringListCounter]);
}

What this does is assigns your Activity to an OnClickListener to handle the click events. If Next was pressed and the counter is within the range of the array list, it will increase the counter. The same for previous. At the end of the click, it will set the text to whatever the ID is. This assumes your strings are in a strings.xml file which is recommended in the Android spec and is static.