When I try to run my app on the emulator I have a tab message saying
"unfortunately,GeoQuiz has stopped working" .......
GeoQuiz is my app's name .......
here is my activity class in the QuizActivity.java file
public class QuizActivity extends ActionBarActivity {
private Button mTrueButton;
private Button mFalseButton;
#Override
protected void onCreate(Bundle savedInstanceState) {
mTrueButton=(Button) findViewById(R.id.true_button);
mTrueButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(QuizActivity.this,R.string.correct_toast,Toast.LENGTH_SHORT).show();
}
});
mFalseButton=(Button) findViewById(R.id.false_button);
mFalseButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(QuizActivity.this, R.string.incorrect_toast, Toast.LENGTH_SHORT).show();
}
});
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_quiz);
}
#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_quiz, 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;
}
return super.onOptionsItemSelected(item);
}
}
I have no images at all in my app
and the min sdk version for this app is API 16:android 4.1 (jelly bean)
and the targeted version is API 21:android 5.0 (Lollipop)
you dont call setContentView at the right place:
you call it at the end of the onCreate method! You have to move these two lines to the beginning of the onCreate Method:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_quiz);
because of that you get a NullPointerException here:
mTrueButton=(Button) findViewById(R.id.true_button);
mTrueButton.setOnClickListener(new View.OnClickListener() { // NPE
Related
I'm working on the android self study Sunshine app and I'm having trouble getting extra menu entries in the action bar.
The most likely reason I've found, is that the OnCreate method of my frame class is not being called and thus the menu is not being inflated.
Here's my MainActivity code:
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Log.d("MainActivity","OnCreate Started 1");
if (savedInstanceState == null) {
Log.d("MainActivity","OnCreate Started 2");
ForecastFragment MyFragment = new ForecastFragment();
if (MyFragment == null){
Log.d("MainActivity","OnCreate Started 3");
}
else{
getSupportFragmentManager().beginTransaction()
.add(R.id.container, MyFragment)
.commit();}
}
}
Here is now the code of my ForecastFragment class:
public class ForecastFragment extends Fragment {
public ForecastFragment() {
}
//#Override
protected void OnCreate(Bundle savedInstanceState){
Log.d("Forecastfragment","OnCreate Started");
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
// Inflate the menu; this adds items to the action bar if it is present.
inflater.inflate(R.menu.forecastfragment, menu);
}
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_refresh) {
FetchWeatherTask WeatherTask = new FetchWeatherTask();
WeatherTask.execute();
return true;
}
return super.onOptionsItemSelected(item);
}
When I run the app, I don't see the logging that the OnCreate method of the ForecastFragment class is being called.
Any ideas?
This is not the exact inherited onCreate method of Fragment
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.i(TAG, "onCreate()");
}
it should be onCreate not OnCreate
I keep getting this error "Error:(60, 12) error: method does not override or implement a method from a supertype" on my last 2 #Overrides im not sure where i went wrong, any help would be helpful. I added the Button billspliting and everything then when to poop. I try to build the APK but I keep getting the two over ride errors.
private TextView totaltextview;
private EditText PercentageTxt;
private EditText Numbertxt;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
totaltextview = (TextView) findViewById(R.id.Totaltextview);
PercentageTxt = (EditText) findViewById(R.id.PercentageTxt);
Numbertxt = (EditText) findViewById(R.id.Numbertxt);
Button CalcBtn = (Button) findViewById(R.id.CalcBtn);
CalcBtn.setOnClickListener(new View.OnClickListener() {
#SuppressLint("SetTextI18n")
#Override
public void onClick(View v) {
float percentage = Float.parseFloat(PercentageTxt.getText().toString());
float dec = percentage / 100;
float total = dec * Float.parseFloat(Numbertxt.getText().toString()) + Float.parseFloat(Numbertxt.getText().toString());
totaltextview.setText(Float.toString(total));
Button billspliting = (Button) findViewById(R.id.Button123);
billspliting.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(First.this, Myotheractivity.class);
startActivity(intent);
}
});
}
#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;
}
return onOptionsItemSelected(item);
}
;
});
}}
Take OnCreateOptionsMenu and OnOptionsItemSelected outside of CalcBtn.setOnClickListener(new View.OnClickListener() as these method are present in Activity not in OnClickListener.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
totaltextview = (TextView) findViewById(R.id.Totaltextview);
PercentageTxt = (EditText) findViewById(R.id.PercentageTxt);
Numbertxt = (EditText) findViewById(R.id.Numbertxt);
Button CalcBtn = (Button) findViewById(R.id.CalcBtn);
CalcBtn.setOnClickListener(new View.OnClickListener() {
#SuppressLint("SetTextI18n")
#Override
public void onClick(View v) {
float percentage = Float.parseFloat(PercentageTxt.getText().toString());
float dec = percentage / 100;
float total = dec * Float.parseFloat(Numbertxt.getText().toString()) + Float.parseFloat(Numbertxt.getText().toString());
totaltextview.setText(Float.toString(total));
Button billspliting = (Button) findViewById(R.id.Button123);
billspliting.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(First.this, Myotheractivity.class);
startActivity(intent);
}
});
}
});
}
#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;
}
return onOptionsItemSelected(item);
}
So, When I try to launch this application it crashes. However, it only crashes when I try to use the setOnClickListener. If I comment out that small section it runs just fine.
public class MainActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
setContentView(R.layout.activity_main);
final TextView textView = (TextView) findViewById(R.id.textView);
final Button button = (Button)findViewById(R.id.button);
super.onCreate(savedInstanceState);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//textView.setText("Boop!");
}
});
}
#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;
}
return super.onOptionsItemSelected(item);
OK Working code! I had to move super.onCreate up, and declair the textview inside the findviewbyID section. However, now it works as I intended. Thank you guys for the help! I just wanted to make something very basic for a date. xD you guys are a life saver.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button button = (Button)findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
TextView textView = (TextView) findViewById(R.id.textView);
textView.setText("Boop!");
}
});
}
#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;
}
return super.onOptionsItemSelected(item);
}
WORKING
The error is coming because you are calling the super.onCreate(savedInstanceState);
after the setContentView and then using the variables.
Reason that the error is not coming until you don't write onClicklister:
The variables textView and button are already null or in inconsistent state, but when you are writing the click listener, the variables are used and you are facing error.
You declared textView as final:
A variable can be declared final. A final variable may only be assigned to once.
final TextView textView = (TextView) findViewById(R.id.textView);
so you cannot modify it.
You must get the view inside onclick method:
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
TextView textView = (TextView) findViewById(R.id.textView);
textView.setText("Boop!");
}
});
I want to change the background-color of another Activity (start) in my Settings-Activity (choose between different colors, sounds etc.).
How can I change the color of another Activity?
I tried to get the Background from my start-Activity (id:start) with:
final RelativeLayout background = (RelativeLayout) findViewById(R.id.start);
but it seems it doesn´t work.
Full Code of the Settings-Activity:
public class activity_settings extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_activity_settings);
ColorChange();
}
public void ColorChange() {
final RelativeLayout background = (RelativeLayout) findViewById(R.id.start);
final RadioButton ChangeToBlue = (RadioButton) findViewById(R.id.button_blue);
final RadioButton ChangeToRed = (RadioButton) findViewById(R.id.button_red);
final Button button_save = (Button) findViewById(R.id.button_save);
button_save.setOnClickListener(new Button.OnClickListener() {
public void onClick(View v) {
ChangeOption(background);
}
});
ChangeToBlue.setOnCheckedChangeListener(new RadioButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
ChangeToBlue(background);
}
});
ChangeToRed.setOnCheckedChangeListener(new RadioButton.OnCheckedChangeListener() {
#Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
ChangeToRed(background);
}
});
}
public void ChangeOption(RelativeLayout background) {
if (background.isEnabled()) {
background.setEnabled(false);
} else {
background.setEnabled(true);
}
}
public void ChangeToBlue(RelativeLayout background) {
background.setBackgroundColor(Color.BLUE);
background.invalidate();
}
public void ChangeToRed(RelativeLayout background) {
background.setBackgroundColor(Color.RED);
background.invalidate();
}
#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_activity_settings, 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;
}
return super.onOptionsItemSelected(item);
}}
Save color code i.e. #F0F0F0 from your setting-activity in a sharedPreference and get this value in onCreate() of activity in which you want to set background.
i just started to use eclipse, and im trying to do my first android application. But apparently something is wrong with my syntax error , and i dont know how can i fix it or where did i do wrongly. so i hope someone here can help me. Thanks :) pardon me for my bad english.
Those underlined in red are errors but i dont know how can i fix them.
starts below here
Here is my .java
public class Category extends Activity { <---(**this sign is underlined in red**)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_category);
Button switchButton = (Button) findViewById(R.id.button1);
switchButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(Category.this, Cake.class);
startActivity(intent);
Button switchButton = (Button) findViewById(R.id.button2);
switchButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(Category.this, Cookie.class);
startActivity(intent);
};
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.category, 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();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
} ^
(**this sign is underlined in red**)
};
Unfortunately you're trying to initialize your button listener in another button listener. That's wrong.
Corrected:
Button switchButton = (Button) findViewById(R.id.button1);
switchButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(Category.this, Cake.class);
startActivity(intent);
};
});
Button switchButton2 = (Button) findViewById(R.id.button2);
switchButton2.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(Category.this, Cookie.class);
startActivity(intent);
};
});