مشکل در اجرای hangman

وقتی پروژه هنگ من رو اجرا می کنم و روی حروفی که در متن مورد نظر ورجود نداره تاچ میکنم به جای تغییر عکس با کرش اپلیکیشن مواجه میشم

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

  private  String wordDashed;
  private Integer failCount;
  private String selectWord(){
    return"Hello World";
  }

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

    final String word = selectWord();
    wordDashed = "";
    for (int i=0; i<word.length(); i++){
      if (word.charAt(i) != ' ') {
        wordDashed += "-";
      } else {
        wordDashed += " ";
      }
    }

    Log.i("test", wordDashed);

    final ImageView img_face = (ImageView) findViewById(R.id.img_face);   
    img_face.setImageResource(R.drawable.face_1);

    final TextView txt_word = (TextView) findViewById(R.id.txt_word);   
    txt_word.setText(wordDashed);

    TextView txt_a = (TextView) findViewById(R.id.txt_a);   
    TextView txt_b = (TextView) findViewById(R.id.txt_b);
    TextView txt_c = (TextView) findViewById(R.id.txt_c);
    TextView txt_d = (TextView) findViewById(R.id.txt_d);
    TextView txt_e = (TextView) findViewById(R.id.txt_e);
    TextView txt_f = (TextView) findViewById(R.id.txt_f);
    TextView txt_g = (TextView) findViewById(R.id.txt_g);
    TextView txt_h = (TextView) findViewById(R.id.txt_h);
    TextView txt_i = (TextView) findViewById(R.id.txt_i);
    TextView txt_j = (TextView) findViewById(R.id.txt_j);
    TextView txt_k = (TextView) findViewById(R.id.txt_k);
    TextView txt_l = (TextView) findViewById(R.id.txt_l);
    TextView txt_m = (TextView) findViewById(R.id.txt_m);
    TextView txt_n = (TextView) findViewById(R.id.txt_n);
    TextView txt_o = (TextView) findViewById(R.id.txt_o);
    TextView txt_p = (TextView) findViewById(R.id.txt_p);
    TextView txt_q = (TextView) findViewById(R.id.txt_q);
    TextView txt_r = (TextView) findViewById(R.id.txt_r);
    TextView txt_s = (TextView) findViewById(R.id.txt_s);
    TextView txt_t = (TextView) findViewById(R.id.txt_t);
    TextView txt_u = (TextView) findViewById(R.id.txt_u);
    TextView txt_v = (TextView) findViewById(R.id.txt_v);
    TextView txt_w = (TextView) findViewById(R.id.txt_w);
    TextView txt_x = (TextView) findViewById(R.id.txt_x);
    TextView txt_y = (TextView) findViewById(R.id.txt_y);
    TextView txt_z = (TextView) findViewById(R.id.txt_z);

    View.OnClickListener listener = new View.OnClickListener() {
      @Override
      public void onClick(View view) {
        TextView textView = (TextView) view;
        String id = textView.getResources().getResourceEntryName(textView.getId());
        String letter = id.replace("txt_", "");
        char letterChar = letter.charAt(0);
        Log.i("Test" , "Clicked On " + letter);

        String wordLowercase = word.toLowerCase();
        if (wordLowercase.contains(letter)) {
          Log.i("Test", "word contain " + letter);
          for (int i=0;i<wordLowercase.length(); i++) {
            if (wordLowercase.charAt(i) == letterChar) {
              char[] wordDashedCharArray = wordDashed.toCharArray();
              wordDashedCharArray[i] = letterChar;
              wordDashed = new String(wordDashedCharArray);
              txt_word.setText(wordDashed);
            }
          }
        } else {
          Log.i("Test", "word not contain " + letter);
          failCount++;
          if (failCount > 8) {
            Log.i("test", "GAME OVER");
          }
          int imageId = R.drawable.face_1;

          switch (failCount) {
            case 1: imageId = R.drawable.face_2; break;
            case 2: imageId = R.drawable.face_3; break;
            case 3: imageId = R.drawable.face_4; break;
            case 4: imageId = R.drawable.face_5; break;
            case 5: imageId = R.drawable.face_6; break;
            case 6: imageId = R.drawable.face_7; break;
            case 7: imageId = R.drawable.face_8; break;
            case 8: imageId = R.drawable.face_9; break;
          }
          img_face.setImageResource(imageId);
        }
        textView.setVisibility(View.INVISIBLE);
      }
    };

    txt_a.setOnClickListener(listener);
    txt_b.setOnClickListener(listener);
    txt_c.setOnClickListener(listener);
    txt_d.setOnClickListener(listener);
    txt_e.setOnClickListener(listener);
    txt_f.setOnClickListener(listener);
    txt_g.setOnClickListener(listener);
    txt_h.setOnClickListener(listener);
    txt_i.setOnClickListener(listener);
    txt_j.setOnClickListener(listener);
    txt_k.setOnClickListener(listener);
    txt_l.setOnClickListener(listener);
    txt_m.setOnClickListener(listener);
    txt_n.setOnClickListener(listener);
    txt_o.setOnClickListener(listener);
    txt_p.setOnClickListener(listener);
    txt_q.setOnClickListener(listener);
    txt_r.setOnClickListener(listener);
    txt_s.setOnClickListener(listener);
    txt_t.setOnClickListener(listener);
    txt_u.setOnClickListener(listener);
    txt_v.setOnClickListener(listener);
    txt_w.setOnClickListener(listener);
    txt_x.setOnClickListener(listener);
    txt_y.setOnClickListener(listener);
    txt_z.setOnClickListener(listener);
  }
}