1. ארועים ומאזינים
android

2. תרשים זרימה של אירוע

5. public class EventActivity extends Activity{
EditText etin;
TextView tvout;
Button bt1;
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_event);
etin=(EditText) findViewById(R.id.etword);
tvout=(TextView) findViewById(R.id.tvoutput);
bt1=(Button) findViewById(R.id.btcheck); }
public void onClick(View v)
String st;
if (bt1==v)
st=etin.getText().toString();
tvout.setText(st);

8. public class EventActivity extends Activity implements OnClickListener{
EditText etin;
TextView tvout;
Button btPush;
Button btClear;
protected void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_event);
etin=(EditText) findViewById(R.id.etword);
tvout=(TextView) findViewById(R.id.tvoutput);
btPush=(Button) findViewById(R.id.btcheck);
btClear=(Button) findViewById(R.id.btclear);
btPush.setOnClickListener(this);
btClear.setOnClickListener(this); }
public void onClick(View v)
String st="???????";
if (btPush==v)
st=etin.getText().toString();
if (btClear==v)
st="#########";
etin.setHint(null);
tvout.setText(st);