I made a little app with an action what can call two fragments. This works absolutely fine even though android studio marks every findViewById(R.id.Example) read, what obvisely means there is something wrong. Only the "R" is marked red. But i dont understand what is wrong? Especially when the app works fine and the compilation dont give any errors.
Here is the main activity:
package silverbeach.meintieralter;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v4.app.FragmentActivity;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
public class MainActivity extends AppCompatActivity {
private FragmentOne fragmentOne;
private FragmentTwo fragmentTwo;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
//Fragmente ankündigen
fragmentOne = (FragmentOne) Fragment.instantiate(this, FragmentOne.class.getName(),null);
fragmentTwo = (FragmentTwo) Fragment.instantiate(this, FragmentTwo.class.getName(),null);
//Fragment 1 wird STANDARTMÄSSIG eingeblendet und ausgeführt
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.add(R.id.flFragmentContainer, fragmentOne);
fragmentTransaction.commit();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()){
case R.id.action_one:{
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.flFragmentContainer, fragmentOne);
fragmentTransaction.commit();
break;
}
case R.id.action_two:{
FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction();
fragmentTransaction.replace(R.id.flFragmentContainer, fragmentTwo);
fragmentTransaction.commit();
break;
}
default:{
}
}
return super.onOptionsItemSelected(item);
}
}
And here is one of the fragments:
package silverbeach.meintieralter;
import android.app.Fragment;
import android.content.Context;
import android.os.Bundle;
import android.os.Vibrator;
import android.support.annotation.Nullable;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.view.View.OnClickListener;
import static android.content.Context.VIBRATOR_SERVICE;
public class FragmentOne extends Fragment {
private TextView out;
private EditText alter;
private Spinner s;
private Button button;
private FloatingActionButton fab;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View layout = inflater.inflate(R.layout.fragment_one, null);
out = (TextView) layout.findViewById(R.id.out);
alter = (EditText) layout.findViewById(R.id.altereingabe);
s = (Spinner) layout.findViewById(R.id.spinner);
button = (Button) layout.findViewById(R.id.button);
fab = (FloatingActionButton) layout.findViewById(R.id.fab);
FloatingActionButton fab = (FloatingActionButton) layout.findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v) {
String text = s.getSelectedItem().toString();
int newage = 404;
double doublenewage = 4.04;
double doubleage;
int intage;
doubleage = Double.parseDouble(alter.getText().toString());
intage = (int) doubleage;
switch (text) {
case "Katze": {
switch (intage) {
default:
Snackbar.make(v, "Leider schon tot.", Snackbar.LENGTH_LONG).show();
out.setText("Leider schon tot.");
break;
}
if (intage <= 119)
Snackbar.make(v, "Du bist eine " + Integer.toString(newage) + " Jahre alte Katze.", Snackbar.LENGTH_LONG).show();
else {
double deadagecat;
deadagecat = intage * 0.283;
long dc = Math.round(deadagecat);
Snackbar.make(v, "Du bist höchstwahrscheinlich schon tot, aber theoretisch wärst du eine " + dc + "-Jährige Katze.", Snackbar.LENGTH_LONG).show();
}
}break;
case "Pferd": {
doublenewage = intage / 3.1;
long longpferdage = Math.round(doublenewage);
newage = (int) longpferdage;
if (newage < 31)
Snackbar.make(v, "Du bist ein " + Integer.toString(newage) + " Jahre altes Pferd", Snackbar.LENGTH_LONG).show();
else
Snackbar.make(v, "Du bist höchstwahrscheinlich schon tot, aber theoretisch wärst du ein " + newage + "-Jähriges Pferd.", Snackbar.LENGTH_LONG).show();
}break;
case "Hund": {
newage = intage / 7;
if (newage < 15)
Snackbar.make(v, "Du bist ein " + Integer.toString(newage) + " Jahre alter Hund.", Snackbar.LENGTH_LONG).show();
else
Snackbar.make(v, "Du bist höchstwahrscheinlich schon tot, aber theoretisch wärst du ein " + newage + "-Jähriger Hund.", Snackbar.LENGTH_LONG).show();
}break;
case "Meerschweinchen": {
newage = intage / 12;
if (newage < 8)
//out.setText("Du bist ein " + Integer.toString(newage) + " Jahre altes Meerie.");
Snackbar.make(v, "Du bist ein "+Integer.toString(newage)+" Jahre altes Meerie.", Snackbar.LENGTH_LONG).show();
else{
Snackbar.make(v, "Du bist höchstwahrscheinlich schon tot, aber theoretisch wärst du ein " + newage + "-Jähriges Meerie.", Snackbar.LENGTH_LONG).show();}
}break;
}
}
});
// tvText1 = (TextView) layout.findViewById(R.id.tvFragmentOne);
return layout;
}
@Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
//tvText1.setText("Ok View 1 wurde geändert.");
}
}
You simply need to do a rebuild and then clean your project. It's just a build problem from the IDE itself. Give it a Build, a clean and then you're ready to go. Hope this helps