I'm using intent method to make a simple app that takes you from main screen [with an enter button] to another screen which has three options. Code sourced online and seems to be error free, though my app crashes saying "Unfortunately [yourapp], has stopped" immediately after i press the button which is meant to take to the the other screen.
This is my first activity code:
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.widget.Button;
import android.view.View;
import android.view.View.OnClickListener;
public class MainActivity extends Activity {
Button button;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
addListenerOnButton();
}
public void addListenerOnButton() {
final Context context = this;
button = (Button) findViewById(R.id.enterBtn);
button.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View arg0) {
Intent intent = new Intent(context, HomeActivity.class);
startActivity(intent);
}
});
}
}`
And this is my landing screen's activity code:
import android.app.Activity;
import android.os.Bundle;
import android.widget.Button;
public class HomeActivity extends Activity {
Button button;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.home);
}
}
I'm really stuck with this issue and any help would be much appreciated. Many thanks in advance.
Every activity needs to be added in your manifest file under application tag. This seems to be the problem in your case.
Try to post you LogCat so that we might get some more information and if you have not yet added your Activity in the manifest, this is the way of adding it (Activities go under application tag)
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.southmp3"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="14"
android:targetSdkVersion="21" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<application
android:allowBackup="true"
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity
android:name=".MainActivity"
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=".HomeActivity"
android:label="#string/app_name" >
</activity>
</application>
all the Activities should be going under the application tag
I had forgotten to register my new activity on the androidmanifest.xml file. That's what sorted my app crash issue.
Related
I know and I do understand that this question has been asked, but I can't seem to interpret it for my application. I am creating an application - using Android Studio - that opens a Activity (called 'About'). When a user clicks on the 'about button' on my MainActivity, it should launch the 'About' activity. However, when I test this out on my device, it says the app has stopped. And on my output panel, it says something about an error with my Manifest.xml file?
MainActivity:
package com.msp.supercarsounds;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void clickedAbout(View view) {
final int result = 1;
Intent AboutButtonClicked = new Intent (this, About.class);
AboutButtonClicked.putExtra("About", "MainActivity");
startActivityForResult(AboutButtonClicked, result);
}
}
AndroidManifest.xml:
<?xml version="1.0" encoding="utf-8"?>
<manifest
xmlns:android="http://schemas.android.com/apk/res/android"
package="com.msp.supercarsounds">
<uses-sdk android:minSdkVersion="17"
android:targetSdkVersion="22"/>
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
Thank you for your help and time!
You have to declare About activity
<activity android:name=".About">
</activity>
Add this below the </activity> tag of MainActivity
your second activity "about" is not added to manifest.xml add this under the mainactivity
<activity android:name=".about">/activity>
I transformed my project into a library. This project just displays a blank activity. I imported this library into another project where I want to call it thru the projects main activity but I keep on getting the error below even if I already declared the activity inside the projects manifest.
Unable to find explicit activity class {com.package.name/com.package.name.BatibotActivity}; have you declared this activity in your AndroidManifest.xml?
This is my project manifest
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="pak.paks.pocket" >
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme" >
<activity android:name=".MainActivity" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.package.name.BatibotActivity"
android:screenOrientation="portrait" >
</activity>
</application>
</manifest>
What am I doing wrong?
edit:
this is my BatibotActivity
package com.package.name;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class BatibotActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_batibot);
}
}
EDIT2
This is the class that is calling the BatibotActivity
package pak.paks.pocket;
import android.content.ComponentName;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
public void submitBtn(View view) {
Intent intent = new Intent(android.content.Intent.ACTION_VIEW);
intent.setComponent(new ComponentName("com.package.name",
"com.package.name.BatibotActivity"));
startActivity(intent);
}
}
By the log message, you are trying to open com.package.name/com.package.name.BatibotActivity, but the Activity registered on AndroidManifest.xml is pak.paks.pocket/com.package.name.BatibotActivity.
The first parameter for ComponentName is the package name. This is the correct code:
Intent intent = new Intent(android.content.Intent.ACTION_VIEW);
intent.setComponent(new ComponentName("pak.paks.pocket", "com.package.name.BatibotActivity"));
startActivity(intent);
Please check your manifest tag's package attr.
<manifest package="com.package.name">
<application>
...
</application>
</manifest>
I am a new android developer and encountered a problem while following the tutorial on Android's site - http://developer.android.com/training/basics/firstapp/starting-activity.html
My program loads on the emulator fine, but when you type something into the EditText and then hit the send button, a window pops up saying "App has stopped working". It seems as though my new activity isn't being created and I'm not sure as to why. I've scoured the web (and my code) to see if I could get a solution but did so to no avail. Any help would be appreciated.
The code for my first activity:
package com.example.appli;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
public class MainActivity extends Activity {
public final static String EXTRA_MESSAGE = "com.example.myapp.MESSAGE";
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.testlayout);
//////Button myButton = (Button) findViewById(R.id.my_button); //Told in tutorial to put this in onCreate
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
/** Called when the user selects the Send button */
public void sendMessage(View view) {
// Do something in response to button
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);
}
}
The code for my second activity (the one being called)
package com.example.appli;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.widget.TextView;
public class DisplayMessageActivity extends Activity{
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//get message from intent
Intent intent = getIntent();
String message = intent.getStringExtra(MainActivity.EXTRA_MESSAGE);
// Create the text view
TextView textView = new TextView(this);
textView.setTextSize(40);
textView.setText(message);
setContentView(textView);
}
}
The Manifest
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.appli"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="15" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name"
android:theme="#style/AppTheme" >
<activity android:name="com.example.myapp.DisplayMessageActivity" />
<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>
In AndroidManifest File you have declared incorrect package
change
<activity android:name="com.example.myapp.DisplayMessageActivity" />
to
<activity android:name="com.example.appli.DisplayMessageActivity" />
or just
<activity android:name=".DisplayMessageActivity" />
you have declared only one Activity that's also wrong package name
already your manifest has the package name
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.appli"
so just declare like this
<activity android:name=".DisplayMessageActivity" />
and you need to add this in your manifest also
<activity android:name=".MainActivity />
remove the target SDK version that you mentioned
android:targetSdkVersion="15"
Try this
<activity android:name=".DisplayMessageActivity"/>
Instead of
<activity android:name="com.example.myapp.DisplayMessageActivity" />
in your Manifest.xml file.
You has defined the package package com.example.appli; in your activities.
Why have you defined you activity in manifest like <activity android:name="com.example.myapp.DisplayMessageActivity" />?
Replace this line with
<activity android:name=".DisplayMessageActivity" />.
I'm beginner in Android (and java), and I'm just playing around and want to create new View after clicking a button. Here is my code so far:
Main class
package myTests.homeSpace;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class TestsActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button1 = (Button) findViewById(R.id.button1);
button1.setOnClickListener( new OnClickListener()
{
public void onClick(View v)
{
Intent myIntent = new Intent(TestsActivity.this, screen1.class);
startActivity(myIntent);
}
});
}
}
Class to run after clicking button
package myTests.homeSpace;
import android.app.Activity;
import android.os.Bundle;
public class screen1 extends Activity {
#Override
public void onCreate(Bundle SavedBundleInstance)
{
super.onCreate(SavedBundleInstance);
setContentView(R.layout.screen1);
}
}
The problem is, after hitting button I got "Unforunately, Tests has stopped" error. ("Tests" is application name). I know (or guess) the problem is in this line Intent myIntent = new Intent(TestsActivity.this, screen1.class);
I guess my reference to class screen1 is wrong somehow, but I have no idea why. There are no compilation errors nor warnings, layout .xmls shouldn't be wrong.
Could any of you please advice me any solution?
EDIT
MANIFEST
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="myTests.homeSpace"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:name=".TestsActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
CONSOLE OUTPUT
[2012-06-20 19:56:21 - ddms] null
java.lang.NullPointerException
at com.android.ddmlib.JdwpPacket.writeAndConsume(JdwpPacket.java:213)
at com.android.ddmlib.Client.sendAndConsume(Client.java:575)
at com.android.ddmlib.HandleHello.sendHELO(HandleHello.java:142)
at com.android.ddmlib.HandleHello.sendHelloCommands(HandleHello.java:65)
at com.android.ddmlib.Client.getJdwpPacket(Client.java:672)
at com.android.ddmlib.MonitorThread.processClientActivity(MonitorThread.java:317)
at com.android.ddmlib.MonitorThread.run(MonitorThread.java:263)
I bet if you read the crash log somewhere in there says did you forget to declare this activity in the Manifest?
I agree, not declaring the activity in your Manifest file (AndroidManifest.xml) is most likely your problem. See the android developer page on activities for more information. Here is the relevant description:
Declares an activity (an Activity subclass) that implements part of
the application's visual user interface. All activities must be
represented by elements in the manifest file. Any that are
not declared there will not be seen by the system and will never be
run.
I just posted this so you would have more space to research on your own.
Declare your second activity in the Manifest.xml as:
<activity
android:name=".screen1">
</activity>
Just below the declaration of your first activity.
Update:
I have spent more than 2 hours to google, but I can't find the answer. I've add a main.java the handle the activity send from the Login Activity. Now the file tree looks like:
But still got error
E/AndroidRuntime(1282): android.content.ActivityNotFoundException: No
Activity found to handle Intent {
act=com.goodboy.loginIntent.action.main
cat=[android.intent.category.DEFAULT] (has extras) }
I know this question is simple, I am new to android, any help would be appreciated:)
Android allows for Intents that have specific recipients(the Activity or Service) as well as Intents that are broadcast throughout the system to any components that may be listening.
I want to make a PoC(Proof of Concept) that if we do not set setClassName, others can listen your private message.
This PoC is simple, suppose there is Login Activity for App Goodboy, when a user put his username and password in the login activity, and click the login button, the evil activity from App Badboy steal the this message.
However, failed:(
When I click the login button, failed:
And the evil intent got nothing:
The java source code of Login Activity
package com.goodboy.loginIntent;
import com.goodboy.loginIntent.R;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
public class GoodloginActivity extends Activity {
private EditText et_user;
private EditText et_pwd;
private Button btn_login;
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
et_user = (EditText) findViewById(R.id.et_user);
et_pwd = (EditText) findViewById(R.id.et_pwd);
btn_login = (Button) findViewById(R.id.btn_login);
btn_login.setOnClickListener(new OnClickListener(){
public void onClick(View v) {
Intent m_intent = new Intent();
m_intent.putExtra("username", et_user.getText().toString());
m_intent.putExtra("password", et_pwd.getText().toString());
m_intent.setAction("com.goodboy.loginIntent.action.main");
m_intent.addCategory(Intent.CATEGORY_DEFAULT);
startActivity(m_intent);
}
});
}
}
The source code of main.java
package com.goodboy.loginIntent;
import android.app.Activity;
import android.os.Bundle;
import com.goodboy.loginIntent.R;
public class main extends Activity {
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
}
}
The login layout:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >
<EditText
android:id="#+id/et_user"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10" >
<requestFocus />
</EditText>
<EditText
android:id="#+id/et_pwd"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:ems="10"
android:inputType="textPassword" />
<Button
android:id="#+id/btn_login"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button" />
</LinearLayout>
The java source code of evil activity:
package com.badboy.stealIntent;
import com.badboy.stealIntent.R;
import android.app.Activity;
import android.os.Bundle;
import android.widget.Toast;
public class BadIntentActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Toast.makeText(getBaseContext(),
"username: "+this.getIntent().getStringExtra("username")+
"\npassword: "+this.getIntent().getStringExtra("password"),
Toast.LENGTH_SHORT).show();
}
}
Thanks #David Wasser, the manifest of login app(update):
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.goodboy.loginIntent"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:name=".GoodloginActivity"
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=".main"
android:label="#string/main" >
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
The manifest of the badIntent:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.badboy.stealIntent"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="15" />
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:name=".BadIntentActivity"
android:label="#string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
</manifest>
You should take a look at Intent Intercept, an application aimed for developer which, as the name says, intercept any "public" Intent, allowing you to browse the intent setup and data. Intent Intercept is Open source, you can browse the code on GitHub
As for your problem, check that the BadBoy application is registered for the action you're using. Also, take a look at the stacktrace in logcat on goodlogin to see where the activity crashes.
You are probably getting an ActivityNotFoundException when you call startActivity() in GoodloginActivity because there is no Activity known to the system that responds to:
ACTION = "com.goodboy.loginIntent.action.main" and
CATEGORY = CATEGORY_DEFAULT
Have a look at your logcat output.