Android dev: updating ui textview using runOnUiThread, crashes

Question

My goal is when the user tap start button, letters "o" "n" "o" "m" and so forth will appear at the center of the screen. "o" will appear first then after a few seconds will be replaced by "n" then "o" and so forth.

note: for brevity, i just make the guessword = onomatopoeia, first. In reality, guessword will changes every time i tap the start bottom.

this is the code:

As was suggested, I implemented runonuithread but it still crashes:

public class PlayActivity extends ActionBarActivity {

private String guessword = "onomatopoeia";
private TextView showchar;
private int n = guessword.length();
private char letArray[]= guessword.toCharArray();
private Handler handler;
private int i = 0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_play); 
    handler = new Handler();
    showchar = (TextView) findViewById (R.id.charView);
}

public void startGame(View view){
    new Thread() {
        public void run() {
            while(i++ < n) {
                try {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                             showchar.setText(letArray[i]);
                        }
                    });
                    Thread.sleep(300);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
            }
        }
    }.start();

}

Answer 1

I'm guessing this dies on showchar.setText(letArray[i]);. That method requires a java.lang.CharSequence, a char[] or an int resid and you're passing in a single char.

---

Edit 1

Try something like this:

char[] tmpArray = new tmpArray[1];
tmpArray[0] = letArray[i];

then call:

showchar.setText(tmpArray);