Develop Reference

unable to find explicit activity class for as an asynctask

I am getting following exception
android.content.ActivityNotFoundException: Unable to find explicit activity class {com.as.as/com.as.as.LoginActivity$myTask}; have you declared this activity in your AndroidManifest.xml?
No clue as to whats wrong in this
<application
android:name=".ObjectClass.AppController"
android:allowBackup="true"
android:icon="#drawable/app_logo"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity
android:name=".LoginActivity"
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=".PersonalDetails"
android:label="#string/title_activity_personal_details"
android:theme="#style/AppTheme.NoActionBar" />
<activity android:name=".SignUpRegistration.SignUp" />
<activity
android:name="com.intsig.ccrengine.ISCardScanActivity"
android:label="#string/app_name" />

First try to clean and build project again and then try.
If it's not working then append a full path to your LoginActivity.
For e.g. your package name is com.exmaple then you write in your manifest com.example.LoginActivity instead of just .LoginActivity.

Looks like you are creating the Intent in the wrong way.
From this line
Unable to find explicit activity class {com.as.as/com.as.as.LoginActivity$myTask};
You can tell that you are creating an intent which explicit target is the myTask class, when in reality you want to have the Activity class to be the target class.

Your creating activity code is wrong.
new Intent(getBaseContext(), myTask.class);
This code trying to open activity from myTask class. Guess you are waiting for following code:
new Intent(getBaseContext(), AnotherActivity.class);

When I charge my app after using home button it starts in my first activity

I'm sure that this will be a really newbie question but I'm stuck and I don't know how to get out of this!
I have an app that have three activities and when I use HOME button and I open the app again, it goes to the FIRST activity always, even if I was in the second or at the third one.
EDIT 3: My app comes in three activities, the first one is the main menu, the second is a map of tables and the third one are the data of the tables. Depending of the configuration, closing the third activity must bring me to the first one or the second one, and when I'm leaving the third Activity I dont want it to stay on the Activities stack. My program is working fine going from an Activity to another one. My problem is that seems that when I use Home Button my app finishes every Activity except the first one.
Maybe I have to modify anything on the manifest or maybe I have to use in a specifically way the RestoreInstanceState but I'm searching so hard and I can't find anything. Thanks in advance!
Edit 1: I'm adding my 'application' xml part of the Manifest:
<application
android:allowBackup="true"
android:icon="#drawable/icobaccus"
android:label="#string/app_name"
android:theme="#style/AppTheme">
<activity
android:name="com.example.tpv2_tablet.Activity_Start"
android:label="#string/app_name"
android:screenOrientation="landscape"
android:windowSoftInputMode="adjustPan"
android:configChanges="keyboardHidden|keyboard"
android:theme="#android:style/Theme.NoTitleBar">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.example.tpv2_tablet.Activity_Zonas"
android:label="#string/app_name"
android:screenOrientation="landscape"
android:windowSoftInputMode="adjustPan"
android:configChanges="keyboardHidden|keyboard"
android:theme="#android:style/Theme.NoTitleBar">
</activity>
<activity
android:name="com.example.tpv2_tablet.PrintDialogActivity"
android:label="#string/app_name"
android:screenOrientation="landscape"
android:windowSoftInputMode="adjustPan"
android:configChanges="keyboardHidden|keyboard"
android:theme="#android:style/Theme.NoTitleBar">
</activity>
<activity
android:name="com.example.tpv2_tablet.Activity_Mesas"
android:label="#string/app_name"
android:screenOrientation="landscape"
android:windowSoftInputMode="adjustPan"
android:configChanges="keyboardHidden|keyboard">
</activity>
</application>
Edit 2: Maybe I'm doing something wrong when calling other activities or I'm calling a wrong flag:
Intent intent = new Intent(Activity_1.this, Activity_2.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
finish();
startActivity(intent);

Remove
<intent-filter>
<action android:name="android.intent.action.MAIN" />
</intent-filter>
from all activities except launcher activity
To understand the reason why, read Google Documentation here
remove:
android:noHistory="true"
As this will remove the activity from the activity stack
remove:
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
finish();
from:
Intent intent = new Intent(Activity_1.this, Activity_2.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
finish();
startActivity(intent);
to understand the reason check this answer

You need to set android:clearTaskOnlaunch="false" in your android manifest.

Android Intent problems

I'm having an issue trying to go to a specific class within my android application using the Intent.
This is my code setup:
Intent Secondscreenintent = new Intent(this, Secondscreen.class);
The error that it gives me is
android.content.ActivityNotFoundException: Unable to find explicit activity class {/project10.aventus.quiz.Secondscreen}; have you declared this activity in your AndroidManifest.xml?
After looking at my manifest I could not see any mistakes that would indicate this message.
<activity
android:name=".Main"
android:configChanges="orientation|keyboardHidden|screenSize"
android:label="Quiz">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name=".Secondscreen"
android:label="Secondscreen" />
<activity
android:name=".Quizclass"
android:label="Quizclass"/>
These are within the tag within the tag.
But somehow I'm still getting the class not found error. I have even tried to refer the intent to the Main.class and this has given the same error that it cannot find the Main class.
Does anyone have an idea on how to fix this?
Thanks,
Shams.

In you AndroidManifest.xml you will find some thing like this:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="project10.aventus.quiz"
android:versionCode="1"
android:versionName="your_version_code">
...
</manifest>
package defines the root of your implementation. So you don't have to write the full path name if you define Activities, BroadCastReceiver etc...
So you do it in this way:
<activity
android:name=".Secondscreen"
android:label="Secondscreen" />
This entry means - you will find my Secondscreen.java in my root folder aka package. In your case it would be project10.aventus.quiz.
So i quess your Secondscreen.java is not there. I'm creating allways a new subpackage ui in my root folder, so my activity entry looks like this:
<activity
android:name=".ui.Secondscreen"
android:label="#string/second_screen"
android:screenOrientation="portrait" >
</activity>
Now, this entry means - you will find my Secondscreen.java here: project10.aventus.quiz.ui.Secondscreen.java

Android: Can't find activity in the Manifest, but it IS there?

And i can't figure out why! I checked logcat and i saw that the reason it crashed was because it isn't finding the Activity in the manifest file for some unknown reason.
I've looked at similar threads but none of the answers seem to work for me.
Here's the code where i start the activity:
public class MainActivity extends Activity {
/** Called when the activity is first created. */
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//setContentView(R.layout.main);
Intent ntnt = new Intent(MainActivity.this, SettingsActivity.class);
startActivity(ntnt);
}
}
And the manifest file:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="se.jbhalmstad.ndroid"
android:versionCode="1"
android:versionName="1.0">
<uses-sdk android:minSdkVersion="7" />
<application android:icon="#drawable/icon" android:label="#string/app_name">
<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=".SettingsActivity"></activity>
</application>
</manifest>
As you can see i declared the SettingsActivity that i'm trying to start, at the bottom of the Manifest, inside of the tag.
I might be blind, but i can't find anything wrong. Can you?
Let me know if you need more source, but the SettingsActivity should be irrelevant because it doesn't get that var when i run the program.
Source code
If you want to take a closer look, here's the entire source code.
http://www.speedyshare.com/files/30343046/project.zip

The problem is in your SettingsActivity
when you are using PreferenceActivity you use
addPreferencesFromResource(R.layout.settings);
to set contents.
but you are using
setContentView(R.layout.settings);

Could be package name mismatch. What Java package is the activity class in? Must match the one in the manifest, i. e. se.jbhalmstad.ndroid. Or provide full class name in the android:name attribute.
EDIT: I have a working example, and the <activity> element for my Preferences activity looks slightly different:
<activity android:name="Prefs"/>
No dot before Prefs.
Also, check if the SettingsActivity class is public. You never showed it to us.

i think you dont need to add the name of the package to your acitivity name , you can just add your activity SettingActivity like this :
<activity android:name="SettingsActivity" />
because your activity is in the same package that is declared on the manifest :
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="se.jbhalmstad.ndroid"...
let me know if it helps

Be sure that Manifest intent on the right activity and not just the basic Java / Kotlin class file
New -> Activity -> Empty Activity instead of New -> Class/file
or
Use setContentView(R.layout.yours_activity_class_here); OnCreate

ActivityNotFoundException?

I am getting an ActivityNotFoundException in the following code:
Main.java
Intent intent = new Intent();
intent.setAction("com.test.app.TEST");
startActivity(intent); // ActivityNotFoundException
Manifest.xml
<activity android:name=".MainActivity" android:theme="#android:style/Theme.Dialog">
<intent-filter>
<action android:name="com.test.app.TEST" />
</intent-filter>
</activity>

I've had this issue too, as perfectly concisely described by jpahn.
the period at the front did not give any help to me.
even with exactly this (a copy of the original question including edits), I would still get ActivityNotFoundException.
Main.java
Intent intent = new Intent();
intent.setAction("com.test.app.TEST");
startActivity(intent); // ActivityNotFoundException
Manifest.xml
<activity android:name=".MainActivity" android:theme="#android:style/Theme.Dialog">
<intent-filter>
<action android:name="com.test.app.TEST" />
</intent-filter>
</activity>
This was resolved, after much trial-and-error, by simply adding this to the intent-filter in the manifest:
<category android:name="android.intent.category.DEFAULT" />
So the final manifest file contained:
<activity android:name=".MainActivity" android:theme="#android:style/Theme.Dialog">
<intent-filter>
<action android:name="com.test.app.TEST" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>

I got this error after moving an activity class from one package to another.
Clean build solved it (Project -> Clean).

Be sure to declare your activity in the manifest.xml within the aplication:
<application>
<activity android:name=".YourNewActivity"/>
</application>
To start the new Activity:
Intent intent = new Intent(main.this, YourNewActivity.class);
startActivity(intent);
Where main stands for the current activity,

Add a . (dot) before your activity name in Android Manifest. So it should be android:name=".WordsToSpeakMainActivity"

I have some addition to the #Tom Pace answer. The answer is completely right, but to make it more clear:
ActivityNotFoundException occurs because of absence of
<category android:name="android.intent.category.DEFAULT" />
Because when Android OS see this in the manifest file, understands that this activity can receive intent.
The point ActivityNotFoundException thrown is that, when activity(intent-creator-activity) tries to create intent for other activity(intent-receiver-activity), Android OS sees there is intent for receiver activity but receiver activity does not receive anyone. Then Android OS returns null or empty intent to intent-creator-activity. And startActivity throws that exception.
I have found a code from android developers to avoid this exception:
// Verify the original intent will resolve to at least one activity
if (sendIntent.resolveActivity(getPackageManager()) != null) {
startActivity(chooser);
}
Android Developers: Intent Filters

To be safe you can also call your new activity like this:
Intent intent = new Intent();
intent.setClass(this, THECLASSNAME);
startActivity(intent); //
However, you must add the activity to the androidmanifest - and write a . in front of it, e.g.
<activity android:name=".YOURACTIVITYNAME"></activity>

There two types of intents in android framework,
1-Implicit intents that you are using,
<activity android:name=".MainActivity" android:theme="#android:style/Theme.Dialog">
<intent-filter>
<action android:name="com.test.app.TEST" />
</intent-filter>
</activity>
just add one line in intent filter
<intent-filter>
<action android:name="com.test.app.TEST" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
2- Explicit Intents
Intent i=new Intent(CurrentActivity.this,WhereWeWantToGoActivity.class);
startActivity(i);

To launch an activity by a string definition, use:
Intent intent = new Intent();
intent.setComponent(
new ComponentName("com.app", "com.app.activity.TheActivity"));
startActivity(intent);

At the very top of your AndroidManifest.xml, you'll see the package attribute
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.android.example"
and then, in the activity tag, you'll see the name attribute:
<activity
android:name=".Something"
Make sure that the package name and activity name, when joined together, make the full package specification of your Activity i.e.
com.android.example + .Something = com.android.example.Something
Otherwise, you'll get a ActivityNotFoundException.

I found a solution to this problem... I´m using 2 modules in a android studio project, the thing here is that I needed to add the activity to the main manifest file
<activity android:name="com.HeadApp.ARTry.UnityPlayerActivity"
android:clearTaskOnLaunch="false" android:label="#string/app_name"
android:screenOrientation="portrait"
android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen"
/>
I had that in the unity activity manifest, I just copied the activity and paste it in the main manifest and that was it, hope it helps, eve been struggling a lot with this for the past 3 weeks