Develop Reference

FIXED Unable to find explicit activity class annoying error

I did some research one this Exception but none of these answers here helped me. So what I need to do is when I click a list item, it moves to another activity but I end up getting the same annoying Exception. It tells to look into Android Manifest file but everything is alright there!
Here is my code
Intent:
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int position, long id) {
String strItemTextView = mForecastAdapter.getItem(position);
Intent intent = new Intent(getActivity(), DetailActivity.class);
intent.putExtra(Intent.EXTRA_TEXT, strItemTextView);
startActivity(intent);
}
And Android Manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.android.sunshine2">
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name="com.example.android.sunshine2.MainActivity"
android:label="#string/app_name"
android:theme="#style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.android.sunshine2.DetailActivity"
android:label="#string/title_activity_detail"
android:parentActivityName="com.example.android.sunshine2.MainActivity"
android:theme="#style/AppTheme.NoActionBar">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.android.sunshine2.MainActivity" />
</activity>
</application>
</manifest>
UPDATE:
Here is my code for DetailActivity:
package com.example.android.sunshine2;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
public class DetailActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_detail);
if (savedInstanceState == null) {
getSupportFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment())
.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.detail, 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);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_detail, container, false);
return rootView;
}
}
}
I get an exception like this:
android.content.ActivityNotFoundException: Unable to find explicit activity class {com.example.android.sunshine2/com.example.android.sunshine2.DetailActivity}; have you declared this activity in your AndroidManifest.xml?
And it points to this line of the code:
intent.putExtra(Intent.EXTRA_TEXT, strItemTextView);
UPDATE #2:
Now things are getting really weird. If I use relative path for activity name BUT leave a full path for a Parent activity name (Code snippet of manifest file):
<activity
android:name=".DetailActivity" // <!--Activity I wanna go to (relative path)-->
android:label="#string/title_activity_detail"
android:parentActivityName="com.example.android.sunshine2.MainActivity"
android:theme="#style/AppTheme.NoActionBar">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.android.sunshine2.MainActivity" /><!--Full path-->
</activity>
I get the same Exception but this time it points to this line of code:
startActivity(intent);
UPDATE #3:
Please take a look at the comment I managed to fix my problem

You already have a declared package in your manifest:
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.android.sunshine2">
So as far as I remember you should just declare your activity in manifest with relative path only:
<activity
android:name=".DetailActivity"
android:label="#string/title_activity_detail"
android:parentActivityName=".MainActivity"
android:theme="#style/AppTheme.NoActionBar">
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.android.sunshine2.MainActivity" />
</activity>

can you try below code
Intent intent = new Intent(view.getContext(), DetailActivity.class);
intent.putExtra(Intent.EXTRA_TEXT, strItemTextView);

So I managed to fix my problem. Since I am just learning on Udacity, after 2days of no answers I decided to look into the their solution. The problem is that their tutorials are about 1 year old and since then Android Studio was updated quite a lot. When you are creating a new project with fragment on the latest version of Android studio, for a layout you get three files:
activity_main.xml
content_main.xml
fragment_main.xml
As in previous versions of Android Studio, you wold only get two files:
activity_main.xml
fragment_main.xml
So what I did was I deleted content_main.xml and voilà. It worked!
That was really weird and I am marking this question as answered and I hope it will help for other users as well!

Creation of action bar in Android Studio

I am new to the Android development app. I was following the tutorials given in the official site. So far everything was good but when I started to create and modify the action bar, this error started to arise:
Error:Execution failed for task ':app:processDebugManifest'.
Manifest merger failed : Main AndroidManifest.xml at AndroidManifest.xml manifest:package attribute is not declared
My manifest file is this
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
<uses-sdk android:minSdkVersion="14"/>
package="com.mycompany.myfirstapp" >
<application>
<!-- The/main activity (it has no parent activity) -->
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#android:style/Theme.Holo" >
<activity
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.myfirstapp.DisplayMessageActivity"
android:label="#string/title_activity_display_message"
android:parentActivityName="com.example.hpcore.myfirstapp.MyActivity" >
<meta-data
android:name="android.support.PARENT_ACTIVITY"
android:value="com.example.hpcore.myfirstapp.MyActivity" />
</activity>
</application>
</manifest>
And my main activity Java code is this:
package com.example.hpcore.myfirstapp;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.content.Intent;
import android.view.View;
import android.widget.EditText;
import com.mycompany.myfirstapp.DisplayMessageActivity;
public class MyActivity extends ActionBarActivity {
public final static String EXTRA_MESSAGE= "com.hp core.myfirstapp.MESSAGE";
public void sendMessage(View view)
{
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.edit_message);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE,message);
startActivity(intent);
}
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_displaymessage);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main_Activity_actions,menu);
return super.onCreateOptionsMenu(menu);
}
#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.
switch (item.getItemId())
{
case R.id.action_search:
openSearch();
return true;
case R.id.action_settings:
openSettings();
return true;
default:
return super.onOptionsItemSelected(item);
}
}
}
I guess the problem in one of these files.

You package attribute should be part of Manifest Tag-
Change your manifest Tag like below-
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.mycompany.myfirstapp" >
<uses-sdk android:minSdkVersion="14"/>

Display App Icon in action bar under api 11

I'm writing simple tutorial app and for some reason my App icon is not showing up (I want to use it as navigate up button instead of the arrow).
As stated in the topic, I want to do it on Api level 11, however all the sollutions I've found rely on setIcon method.
getActionBar().setIcon(R.drawable.ic_launcher); //only on API >= 14
The fragment preview in Android studio 1.0.2 does show the icon, however the emulator does not, so I'd expect the resource is ok. Also, the search and delete icons are working like a charm. I've tried setting this both as Icon and a logo to no avail.
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.yamba"
android:versionCode="1"
android:versionName="1.0"
>
<uses-permission android:name="android.permission.INTERNET"/>
<uses-sdk
android:minSdkVersion="11"
android:targetSdkVersion="21"/>
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/Theme.AppCompat.Light"
android:logo="#drawable/ic_launcher"
>
<activity
android:parentActivityName=".MainActivity"
android:name=".StatusActivity"
android:label="#string/app_name" >
</activity>
<!--- The labe is what's displayed at the taskbar!-->
<activity
android:parentActivityName=".MainActivity"
android:name=".SettingsActivity"
android:label="#string/title_activity_settings" >
</activity>
<activity
android:name=".MainActivity"
android:label="#string/title_activity_main" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
activity_settings.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
android:layout_height="match_parent" android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
android:paddingBottom="#dimen/activity_vertical_margin"
tools:context="com.example.yamba.SettingsActivity">
<TextView android:text=""
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</RelativeLayout>
menu_settings.xml
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
tools:context="com.example.yamba.SettingsActivity">
<item android:id="#+id/action_settings" android:title="#string/action_settings"
android:orderInCategory="100" app:showAsAction="never" />
</menu>
SettingsActivity.java
package com.example.yamba;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Intent;
import android.os.Build;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
public class SettingsActivity extends ActionBarActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState == null){
SettingsFragment fragment = new SettingsFragment();
getFragmentManager().beginTransaction().add(android.R.id.content, fragment, fragment.getClass().getSimpleName()).commit();
setContentView(R.layout.activity_settings);
// getSupportActionBar().setDefaultDisplayHomeAsUpEnabled(true);
// only for API>=14
// getActionBar().setDisplayShowHomeEnabled(true);
// getActionBar().setIcon(R.drawable.ic_launcher);
}
}
#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_settings, menu);
// return true;
// 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();
switch(id){
case R.id.action_settings:
startActivity(new Intent(this, SettingsActivity.class));
return true;
case R.id.action_tweet:
startActivity(new Intent(this, com.example.yamba.StatusActivity.class));
return true;
default:
return false;
}
}
}
SettingsFragment.java
package com.example.yamba;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceFragment;
import android.preference.PreferenceManager;
/**
* Created by me on 19-01-2015.
*/
public class SettingsFragment extends PreferenceFragment implements SharedPreferences.OnSharedPreferenceChangeListener {
private SharedPreferences prefs;
#Override
public void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
addPreferencesFromResource(R.xml.settings);
}
public void onStart(){
super.onStart();
prefs= PreferenceManager.getDefaultSharedPreferences(getActivity());
prefs.registerOnSharedPreferenceChangeListener(this);
}
#Override
public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
}
}
I've stumbled upon suggestion that I may be able to define custom style based on one of the existing styles, but can't quite figure out how to approach it.
If you need any other file, let me know and thanks for your time.

since it's API 11..
did you try using the support libraries?
try switching
getActionBar().setIcon(R.drawable.ic_launcher);
with :
getSupportActionBar().setIcon(R.drawable.ic_launcher);
tell me if it works and we'll continue from there :)

Activity in android not starting as intended

The scenario I have consists of 3 activities:
1- Homepage
2-Login
3-Register
The thing is now Home page has 2 buttons one login and one for homepage , and the login activity should be called from either this button or from inside register after I am done registering ,also both login and register activities inflate 2 different fragments.
The problem : Login activity doesnt start , instead it sometimes just blinks with the layout it should inflate for a split second and then backs to the previous activity whichever one it is , also when I replaced the login activity with another activity it started normally with no problems
Any idea what that might be.
NOTE: I'm not getting any errors or so
Signin Activity code:
package engezni.Activties;
import android.annotation.TargetApi;
import android.app.ActionBar;
import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.WindowManager;
import android.widget.FrameLayout;
import android.widget.TextView;
import Fragments.SigninFragment;
import engezni.Activties.R;
public class SignInScreen extends Activity {
FrameLayout frameLayout;
SigninFragment signinFragment;
TextView signinScreen;
#TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_sign_in_screen);
this.getWindow().setSoftInputMode(WindowManager.LayoutParams.SOFT_INPUT_STATE_ALWAYS_HIDDEN);
getActionBar().setCustomView(R.layout.custom_action_bar);
getActionBar().setDisplayOptions(ActionBar.DISPLAY_SHOW_CUSTOM);
/*Setting text to the textview in the xml actionbar layout */
signinScreen = (TextView) findViewById(R.id.actionbarTitleOrderScreen);
signinScreen.setText("Sign In");
getActionBar().setDisplayHomeAsUpEnabled(true);
getActionBar().setHomeButtonEnabled(true);
getActionBar().setDisplayShowHomeEnabled(false);
getActionBar().setBackgroundDrawable(getResources().getDrawable(R.drawable.actionbar));
getActionBar().setHomeAsUpIndicator(getResources().getDrawable(R.drawable.backlogo));
frameLayout=(FrameLayout)findViewById(R.id.signin_framelayout);
signinFragment=new SigninFragment();
if (findViewById(R.id.signin_framelayout) != null) {
if (savedInstanceState != null) {
return;
}
signinFragment.setArguments(getIntent().getExtras());
getFragmentManager().beginTransaction().add(R.id.signin_framelayout, signinFragment).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.sign_in_screen, menu);
onBackPressed();
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);
}
}
And then here is the manifest
<uses-permission android:name="android.permission.INTERNET" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".SplashScreen"
android:label="#string/app_name"
android:screenOrientation="portrait"
android:theme="#android:style/Theme.Light.NoTitleBar.Fullscreen" >
>
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".HomeScreen"
android:label="#string/title_activity_home_screen"
android:screenOrientation="portrait" >
</activity>
<activity
android:name=".SignInScreen"
android:label="#string/title_activity_sign_in_screen"
android:screenOrientation="portrait" >
</activity>
<activity
android:name=".RegisterScreen"
android:label="#string/title_activity_register_screen"
android:screenOrientation="portrait" >
</activity>
<activity
android:name=".MyActivity"
android:label="#string/title_activity_my" >
</activity>
</application>

Problem:
getMenuInflater().inflate(R.menu.sign_in_screen, menu);
onBackPressed();
When the onCreateOptionsMenu is called that is where you go back to the last activity because you called onBackPressed which will destroy your current activity.
solution:
remove the onBackPressed

Manually creating main.xml error

For my project I have to have two .java classes and two .xml files. The first one that I have created is SplashActivity.java. After I have created that class, put some code in there, and worked with my activity_splash.xml. I needed to create the MainActivity.java class. I went into the
AndroidManifest.xml -> Application -> Add -> Actiivity. Name ->
.MainActivity
In my MainActivity.java class I write an onCreate() method to create the activity_main.xml. However, my eclipse emulator underlines the activity_main with a red underline. When I move my mouse to it, it gives me several options "Create filed "activity_main" in type layout", "Create constant "activity_main" in type layout". I am not sure which ones of those are correct way to fix the issue that's why I decided not to mess with R.java. But I am confused why I have that error because as far as I am concerned my code is correct.
The following are the codes:
SplashActivity.java
package com.example.easternmusic;
import java.util.Timer;
import java.util.TimerTask;
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
public class SplashActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_splash);
TimerTask task = new TimerTask() {
#Override
public void run() {
// TODO Auto-generated method stub
finish();
startActivity(new
Intent(SplashActivity.this,MainActivity.class));
}
};
Timer opening = new Timer ();
opening.schedule(task, 5000);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).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.splash, 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);
}
/**
* A placeholder fragment containing a simple view.
*/
public static class PlaceholderFragment extends Fragment {
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_splash,
container, false);
return rootView;
}
}
}
AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.easternmusic"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="19"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name="com.example.easternmusic.SplashActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".MainActivity"></activity>
</application>
</manifest>
MainActivity.java
package com.example.easternmusic;
import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.os.Build;
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
}

Each activity consist of a layout(xml file) and a java class. Here you create the class MainActivity but you forget to add layout of the activity i.e xml file.when you write this setContentView(R.layout.activity_main);. its mean you are setting layout here.Activity_main is the name of the layout file.which you dont add in your layout folder. So the answer to this question is go to your layout folder and add xml file with name activity_main. Your problem will be solved.