I'm working on activities communication.
This is my main2activity class:
public class Main2Activity extends AppCompatActivity {
TextView textView ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
textView =(TextView) findViewById(R.id.textView2);
Intent intent = getIntent();
String received = intent.getStringExtra("input");
textView.setText(received);
}
protected void changeActivity(View view){
Intent intent = new Intent(getApplicationContext(),MainActivity.class);
startActivity(intent);
}}
I am using a editText at mainActivity. Write something on editText than
protected void changeActivity(View view){
userInput = findViewById(R.id.editText);
Intent intent = new Intent(getApplicationContext(),Main2Activity.class);
intent.putExtra("input",userInput.getText().toString());
startActivity(intent);
}
Mainactivity buttoncommand like this press button and send what am i write on editText. But i dont understand something. if i change place textView =(TextView) findViewById(R.id.textView2); this code to out of the method. I am use it under the class. like this
public class Main2Activity extends AppCompatActivity {
TextView textView =(TextView) findViewById(R.id.textView2);
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main2);
Intent intent = getIntent();
String received = intent.getStringExtra("input");
textView.setText(received);
}
protected void changeActivity(View view){
Intent intent = new Intent(getApplicationContext(),MainActivity.class);
startActivity(intent);
}}
application doesn't work on emulator i write something on editText and click button then app go wrong. I don't understand this. Reality(For real smartphones not emulator) is that true? İf reality doesn't work. why what is my mistake?
