I am new in android development and do not have an in depth knowledge of Java. I am stuck on a problem for a long time. I am trying to open a new activity on button click. But I am getting an error that error: not an enclosing class: Katra_home.
Here is the code for MainActivity.java
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button btn=(Button)findViewById(R.id.bhawan1);
btn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
Intent myIntent = new Intent(Katra_home.this, Katra_home.class);
Katra_home.this.startActivity(myIntent);
}
});
And this is the code for Katra_home.java
public class Katra_home extends BaseActivity {
protected static final float MAX_TEXT_SCALE_DELTA = 0.3f;
private ViewPager mPager;
private NavigationAdapter mPagerAdapter;
private SlidingTabLayout mSlidingTabLayout;
private int mFlexibleSpaceHeight;
private int mTabHeight;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.katra_home);
ActionBar ab = getSupportActionBar();
if (ab != null) {
ab.setDisplayHomeAsUpEnabled(true);
ab.setHomeButtonEnabled(true);
}
Though I have seen many answers on stackoverflow but I could not understand them as I am new in android development. So I would like to ask what changes do I need to make in my code to make it work.
It should be
Intent myIntent = new Intent(this, Katra_home.class);
startActivity(myIntent);
You have to use existing activity context to start new activity, new activity is not created yet, and you cannot use its context or call methods upon it.
not an enclosing class error is thrown because of your usage of this keyword. this is a reference to the current object — the object whose method or constructor is being called. With this you can only refer to any member of the current object from within an instance method or a constructor.
Katra_home.this is invalid construct
Intent myIntent = new Intent(MainActivity.this, Katra_home.class);
startActivity(myIntent);
This Should the perfect one :)
you are calling the context of not existing activity...so just replace your code in onClick(View v) as
Intent intent=new Intent(MainActivity.this,Katra_home.class);
startActivity(intent);
it will definitely works....
String user_email = email.getText().toString().trim();
firebaseAuth
.createUserWithEmailAndPassword(user_email,user_password)
.addOnCompleteListener(new OnCompleteListener<AuthResult>() {
#Override
public void onComplete(#NonNull Task<AuthResult> task) {
if(task.isSuccessful()) {
Toast.makeText(RegistraionActivity.this, "Registration sucessful", Toast.LENGTH_SHORT).show();
startActivities(new Intent(RegistraionActivity.this,MainActivity.class));
}else{
Toast.makeText(RegistraionActivity.this, "Registration failed", Toast.LENGTH_SHORT).show();
}
}
});
replace code in onClick() method with this:
Intent myIntent = new Intent(this, Katra_home.class);
startActivity(myIntent);
startActivity(new Intent(this, Katra_home.class));
try this one it will be work
Related
After pressing the button I would like to go to the second activity, enter the data in the second activity and then return to the main activity, but having data in ListView. This is my code:
MainActivity:
public class MainActivity extends AppCompatActivity {
Button button;
ListView listView;
String name;
private static final int REQUEST_CODE = 1;
ArrayAdapter<String> adapter;
ArrayList<String> nameList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = findViewById(R.id.button2);
listView = findViewById(R.id.CarList);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent(MainActivity.this, SecondActivity.class);
startActivityForResult(i, REQUEST_CODE);
}
});
nameList = new ArrayList<String>();
nameList.addAll(Arrays.asList(name));
adapter = new ArrayAdapter<String>(this, R.layout.element, nameList);
listView.setAdapter(adapter);
}
protected void onActivityResult(int requestCode, int resultCode, Intent i){
if (resultCode == RESULT_OK && requestCode == REQUEST_CODE) {
name = i.getStringExtra("name");
}
}
}
And this is my SecondActivity:
public class SecondActivity extends AppCompatActivity {
EditText editText;
Button button2;
String name;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_second);
editText = findViewById(R.id.editText);
button2 = findViewById(R.id.button);
}
public void finish() {
Intent i = new Intent();
name = editText.getText().toString();
i.putExtra("name", name);
setResult(RESULT_OK, i);
super.finish();
}
}
What could I change to make the application work? Because now I only get the message that: app has stopped, but I don't receive information about any error.
After pressing the button I would like to go to the second activity, enter the data in the second activity and then return to the main activity, but having data in ListView.
What could I change to make the application work? Because now I only get the message that: app has stopped, but I don't receive information about any error.
This is simply because you've incorrectly thinking that Activity.finish() is always called whenever you close the activity. But it never be called by the Android. Take a look for this Lifecyle picture from Activity-lifecycle concepts:
you can see that only onStop() then onDestroy() is called when activity is closed.
You need to call the finish() method manually to send your intent. Or, the better way, create a method that only build and set the intent for the result. Something like this:
private void prepareResult(String name) {
Intent i = new Intent();
i.putExtra("name", name);
setResult(RESULT_OK, i);
}
then call it whenever you want to close your activity:
String name = editText.getText().toString();
prepareResult(name);
finish();
Or you can override the onBackPressed() to also handing the back pressed, like the following:
#Override
public void onBackPressed() {
Intent i = new Intent();
name = editText.getText().toString();
i.putExtra("name", name);
setResult(RESULT_OK, i);
// The default implementation simply finishes the current activity
// see the documentation.
super.onBackPressed();
}
I created a project that use RecyclerView and CardView (for PointOfInterest). These 5 activities are relate to each other :
PointOfInterest.java
PlacesAdapter.java
Places.java
layout_poi.xml
activity_point_of_interest.xml
Meanwhile in activity_main.xml I design the Main Menu together with some buttons. One of the button named Rapid Penang (id: rapid_btn). I call an activity of Rapid Penang (from MainActivity.java) like below:
public class MainActivity extends AppCompatActivity {
private Button button_for_rapid;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// to call Rapid Penang class
button_for_rapid = (Button) findViewById(R.id.rapid_btn);
button_for_rapid.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
openRapid();
}
});
}
public void openRapid()
{
Intent intent_rapid = new Intent(this, RapidPenang.class);
startActivity(intent_rapid);
}
}
RapidPenang consist of only one activity and it is success. But when I try to do exactly the same to PointOfInterest activites (as mention above), suddenly the app were crashed.
This is how I try to open PointOfInterest activites from a button in MainMenu called Point Of Interest:
private Button button_for_poi;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// to call Point Of Interest class
button_for_poi = (Button) findViewById(R.id.poi_btn);
button_for_poi.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
openPOI();
}
});
}
public void openPOI()
{
Intent intent_poi = new Intent(this, PointOfInterest.class);
Intent intent_poi2 = new Intent(this, PlacesAdapter.class);
Intent intent_poi3 = new Intent(this, Places.class);
startActivity(intent_poi);
}
Firstly check your activity is define in Android manifest file and then call
StartActivity(new Intent(getApplicationcontext(),RapidPenang.class));
That's it
Here is my code:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnSighin = (Button) findViewById(R.id.btnSignIn);
btnSignUp = (Button) findViewById(R.id.btnSignUp);
btnSignUp.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent j = new Intent(MainActivity.this, SignUp.class);
startActivity(SignUp);
}
});
btnSighin.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick (View view) {
Intent k = new Intent(MainActivity.this, SignIn.class);
startActivity(SignIn);
}
});
}
I am working on an app that allows customers to book appointments and in order to do so, they need to sign up or sign in. I have activities made for both of them and I can't run it without getting the "Expression Expected" and I'm new to Android Studio and have no idea what to do. Any help?
You are missing some information. Anyway, i see that you have mistakes in lines
startActivity(SignUp);
and
startActivity(SignIn);
The correct way should be startActivity(j) and startActivity(k) respectively
You have to pass the intent object to the start activity method not the signup or signin class
So it should be startActivity(i) and startActivity(j)
I have two activities that I would like to send data between. I would like to send two strings from the second activity to the first, where the strings will be manipulated and applied to the code. Here is the intent I have in the second activity to send the strings to the first activity:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
phoneNum = (EditText)findViewById(R.id.phoneNum);
msgCounter = (EditText)findViewById(R.id.msgCount);
apply = (Button)findViewById(R.id.butto);
save = (Button)findViewById(R.id.butt);
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent pass = new Intent();
pass.putExtra("value", phoneNum.getText().toString());
pass.putExtra("cost",msgCounter.getText().toString());
startActivity(pass);
}
});
And here is the intent I have in the first acitivity to receive the data:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_text_messages);
request_code = 1;
FloatingActionButton button = (FloatingActionButton) findViewById(R.id.but);
assert button != null;
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(TextMessages.this,Settings.class);
startActivityForResult(intent, request_code);
Intent a = new Intent(TextMessages.this,Settings.class);
startActivityForResult(a, recode);
}
});
Intent pass = getIntent();
String address = pass.getStringExtra("value");
String string2 = pass.getStringExtra("cost");
However, the app always crashes when I start it. So I can not use any of the data. Thanks in advance to any help I may receive.
In the first activity you should get your strings from onActivityResult. You shouldn't use startActivity in second activity.
Checkout this link for more information
https://developer.android.com/training/basics/intents/result.html
In your second activity you should use setResult method.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
phoneNum = (EditText)findViewById(R.id.phoneNum);
msgCounter = (EditText)findViewById(R.id.msgCount);
apply = (Button)findViewById(R.id.butto);
save = (Button)findViewById(R.id.butt);
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent pass = new Intent();
pass.putExtra("value", phoneNum.getText().toString());
pass.putExtra("cost",msgCounter.getText().toString());
setResult(Activity.RESULT_OK,pass);
finish();
}
});
In your first activity you should get Intent data inside the onActivityResult method.
#Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == request_code) {
if(resultCode == Activity.RESULT_OK){
String value=data.getStringExtra("value");
String cost=data.getStringExtra("cost");
//handle value and cost.
}
}
}
I think it's because you missed out to put the target Activity class when you instantiate your intent. It should be like this:
Intent pass = new Intent(TargetActivity.class);
pass.putExtra("value", phoneNum.getText().toString());
pass.putExtra("cost",msgCounter.getText().toString());
startActivity(pass);
Hope it helps.
EDIT: But I agree with Abdullah. Since the first activity started the second activity, use onActivityResult to pass values to the first activity.
My guess is, the app starts into the second code block you posted. There is no value for String address = pass.getStringExtra("value"); or String string2 = pass.getStringExtra("cost"); when you start your app - only when the second activity sends these to the first activity. I would recommend finding a way to determine if its the second activity creating the first activity or creating a method to set these values in the first activity and call it in the second activity. Also, your second activity should be:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_settings);
phoneNum = (EditText)findViewById(R.id.phoneNum);
msgCounter = (EditText)findViewById(R.id.msgCount);
apply = (Button)findViewById(R.id.butto);
save = (Button)findViewById(R.id.butt);
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent pass = new Intent(SecondActivity.this, FirstActivity.class);
pass.putExtra("value", phoneNum.getText().toString());
pass.putExtra("cost",msgCounter.getText().toString());
startActivity(pass);
}
});
New to Java. I am trying to create an explicit Intent to launch send the user to a new tab and pass some data to it. The problem I think I am having is getting the Context of the parent object that I can pass to the Intent Constructor. "This" is not correct. The onCreate code is below. Any pointers to examples would be helpful
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.quickactivity);
final Button goButton = (Button) findViewById(R.id.go);
goButton.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
Intent i = new Intent(this, TimeActivity.class);
}
});
}
You can also use:
Intent i = new Intent(v.getContext(), TimeActivity.class);
More info here
Use
<MyClassName>.this
instead. Replacing by the actual class in which this method resides