Navigate from fragment to activity
Question
I know this is a question frequently asked, but after reading the many questions and solutions on stack overflow I am could not find a good solution to my problem. i have a fragment and i would like to navigate to the main activity when a user does press the OK button of the AlertDialog but my application crashes. i can't find what is wrong with my code. thanks for your help in advanced.
i can't see what i did wrong here
private void buildConfirmDialog() {
AlertDialog.Builder confirmBuilder = new AlertDialog.Builder(getActivity());
confirmBuilder.setTitle("Are you sure");
confirmBuilder.setMessage("Are you sure you want to save the note");
confirmBuilder.setPositiveButton("Confirm", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Log.d("Save Note", "Note title:" + title.getText() + "Note message:"
+ message.getText() + "Note category:" + savedButtonCategory);
Intent intent = new Intent(getActivity(), MainActivity.class);
startActivity(intent);
}
});
confirmBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
}
});
confirmDialogObject = confirmBuilder.create();
}
Here is my fragment
public class NoteEditFragment extends android.app.Fragment {
private ImageButton noteCatButton;
private EditText title, message;
private Note.Category savedButtonCategory;
private AlertDialog categoryDialogObject,confirmDialogObject;
public NoteEditFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View fragmentLayout = inflater.inflate(R.layout.fragment_note_edit, container, false);
EditText title = fragmentLayout.findViewById(R.id.editNoteTitle);
EditText message = (EditText) fragmentLayout.findViewById(R.id.editNoteMessage);
noteCatButton = (ImageButton) fragmentLayout.findViewById(R.id.editNoteButton);
Button savedButton = (Button) fragmentLayout.findViewById(R.id.saveNote);
//populate widgets with note data
Intent intent = getActivity().getIntent();
title.setText(intent.getExtras().getString(MainActivity.title, ""));
message.setText(intent.getExtras().getString(MainActivity.MESSAGE, ""));
Note.Category notCat = (Note.Category) intent.getSerializableExtra(MainActivity.CATEGORY);
noteCatButton.setImageResource(Note.categoryToDrawble(notCat));
buildCategoryDialog();
buildConfirmDialog();
noteCatButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
categoryDialogObject.show();
}
});
savedButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
confirmDialogObject.show();
}
});
return fragmentLayout;
}
private void buildCategoryDialog() {
final String[] categories = new String[]
{"Personal", "Technical", "Quote", "Financial"};
AlertDialog.Builder categoryBuilder = new AlertDialog.Builder(getActivity());
categoryBuilder.setTitle("Choose Note Type");
categoryBuilder.setSingleChoiceItems(categories, 0, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int item) {
categoryDialogObject.cancel();
switch (item) {
case 0:
savedButtonCategory = Note.Category.PERSONAL;
noteCatButton.setImageResource(R.drawable.images);
break;
case 1:
savedButtonCategory = Note.Category.TECHNICHAL;
noteCatButton.setImageResource(R.drawable.t);
break;
case 2:
savedButtonCategory = Note.Category.QUOTE;
noteCatButton.setImageResource(R.drawable.q);
break;
case 3:
savedButtonCategory = Note.Category.FENANCE;
noteCatButton.setImageResource(R.drawable.f);
break;
}
}
});
categoryDialogObject = categoryBuilder.create();
}
private void buildConfirmDialog() {
AlertDialog.Builder confirmBuilder = new AlertDialog.Builder(getActivity());
confirmBuilder.setTitle("Are you sure");
confirmBuilder.setMessage("Are you sure you want to save the note");
confirmBuilder.setPositiveButton("Confirm", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Log.d("Save Note", "Note title:" + title.getText() + "Note message:"
+ message.getText() + "Note category:" + savedButtonCategory);
Intent intent = new Intent(getActivity(), MainActivity.class);
startActivity(intent);
}
});
confirmBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
}
});
confirmDialogObject = confirmBuilder.create();
}
}
Here is my MainActivity
public class MainActivity extends AppCompatActivity {
public static final String id = "ricom.gmail.com.notebook3.Identifier";
public static final String title = "ricom.gmail.com.notebook3.Title";
public static final String MESSAGE = "ricom.gmail.com.notebook3.Message";
public static final String CATEGORY = "ricom.gmail.com.notebook3.Category";
public static final String NOTE_FRAGMENT_TO_LOAD_EXTRA = "ricom.gmail.com.notebook3.Fragment_To_Load";
public enum FragmentToLaunch {VIEW, EDIT, CREATE}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
}
@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) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
} else if (id == R.id.action_add_note) {
Intent intent = new Intent(this, NoteDetailActivity.class);
intent.putExtra(MainActivity.NOTE_FRAGMENT_TO_LOAD_EXTRA, FragmentToLaunch.CREATE);
startActivity(intent);
return true;
}
return super.onOptionsItemSelected(item);
}
}
Crash report
03-09 08:14:33.816 31586-31586/ricom.gmail.com.myapplication12 E/AndroidRuntime: FATAL EXCEPTION: main Process: ricom.gmail.com.myapplication12, PID: 31586 java.lang.NullPointerException: Attempt to invoke virtual method 'android.text.Editable android.widget.EditText.getText()' on a null object reference at ricom.gmail.com.myapplication12.NoteEditFragment$4.onClick(NoteEditFragment.java:121) at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:166) at android.os.Handler.dispatchMessage(Handler.java:106) at android.os.Looper.loop(Looper.java:164) at android.app.ActivityThread.main(ActivityThread.java:6494) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
it is telling that there is an error here
Log.d("Save Note", "Note title:" + title.getText() + "Note message:"
+ message.getText() + "Note category:" + savedButtonCategory);
2 answers
solution1
0 ACCPTED 2018-03-08 13:04:49
You just have to use simple intents..
Intent i = new Intent(getActivity(), DetailActivity.class);
getActivity().startActivity(i);
Actually you use
getActivity()
to get activity to which a fragment is attached.(that is the first parameter of Intent())
solution2
0 2018-03-09 06:49:27
public class NoteEditFragment extends android.app.Fragment {
private ImageButton noteCatButton;
private EditText title, message;
private Note.Category savedButtonCategory;
private AlertDialog categoryDialogObject,confirmDialogObject;
public NoteEditFragment() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View fragmentLayout = inflater.inflate(R.layout.fragment_note_edit, container, false);
//i replaced this one
/*
EditText title = fragmentLayout.findViewById(R.id.editNoteTitle);
EditText message = (EditText) fragmentLayout.findViewById(R.id.editNoteMessage);
*/
// with that one
title = fragmentLayout.findViewById(R.id.editNoteTitle);
message = (EditText) fragmentLayout.findViewById(R.id.editNoteMessage);
noteCatButton = (ImageButton) fragmentLayout.findViewById(R.id.editNoteButton);
Button savedButton = (Button) fragmentLayout.findViewById(R.id.saveNote);
//populate widgets with note data
Intent intent = getActivity().getIntent();
title.setText(intent.getExtras().getString(MainActivity.title, ""));
message.setText(intent.getExtras().getString(MainActivity.MESSAGE, ""));
Note.Category notCat = (Note.Category) intent.getSerializableExtra(MainActivity.CATEGORY);
noteCatButton.setImageResource(Note.categoryToDrawble(notCat));
buildCategoryDialog();
buildConfirmDialog();
noteCatButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
categoryDialogObject.show();
}
});
savedButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
confirmDialogObject.show();
}
});
return fragmentLayout;
}
private void buildCategoryDialog() {
final String[] categories = new String[]
{"Personal", "Technical", "Quote", "Financial"};
AlertDialog.Builder categoryBuilder = new AlertDialog.Builder(getActivity());
categoryBuilder.setTitle("Choose Note Type");
categoryBuilder.setSingleChoiceItems(categories, 0, new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int item) {
categoryDialogObject.cancel();
switch (item) {
case 0:
savedButtonCategory = Note.Category.PERSONAL;
noteCatButton.setImageResource(R.drawable.images);
break;
case 1:
savedButtonCategory = Note.Category.TECHNICHAL;
noteCatButton.setImageResource(R.drawable.t);
break;
case 2:
savedButtonCategory = Note.Category.QUOTE;
noteCatButton.setImageResource(R.drawable.q);
break;
case 3:
savedButtonCategory = Note.Category.FENANCE;
noteCatButton.setImageResource(R.drawable.f);
break;
}
}
});
categoryDialogObject = categoryBuilder.create();
}
private void buildConfirmDialog() {
AlertDialog.Builder confirmBuilder = new AlertDialog.Builder(getActivity());
confirmBuilder.setTitle("Are you sure");
confirmBuilder.setMessage("Are you sure you want to save the note");
confirmBuilder.setPositiveButton("Confirm", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
Log.d("Save Note", "Note title:" + title.getText() + "Note message:"
+ message.getText() + "Note category:" + savedButtonCategory);
Intent intent = new Intent(getActivity(), MainActivity.class);
startActivity(intent);
}
});
confirmBuilder.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialogInterface, int i) {
}
});
confirmDialogObject = confirmBuilder.create();
}
}
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