ActivityNotFoundException when calling activity of another application - android

I keep getting "ActivityNotFoundException: Unable to find explicit activity class ... " when using Eclipse's emulator to call the activity of another application from an application. Perhaps the problem maybe related to I am not able to download to/find both applications at the same time when I click on "Manage Applications" in Settings. This is the first project I need to call the activity of another application. But I am not sure the code is correct either. Please help me determine if there are errors in the code snippets I present below. It is hinted that I can set the action field of the intent to achieve the objective but have not found learning material for this. I learned about using the setComponent method in the calling app and to add android:export to the called activity's AndroidManifest.xml. Thanks in advance!
Calling app's relevant source code:
Intent intent = new Intent();
intent.setComponent(new ComponentName("com.MyPackage", om.MyPackage.Activity1));
startActivity(intent);
Calling app's relevant AndroidManifest.xml :
<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=".Activity1">
<intent-filter>
<action android:name="com.MyPackage.Activity1" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>
</application>
Relevant code of AndroidManifest.xml of the activity of another application
<activity android:name=".Activity1" android:exported = "true">
<intent-filter>
<action android:name="com.MyPackage.Activity1" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>


Firstly point out that you're trying to start Activity in Application2 from Activity in Application1
You have to give them separate namespaces
both applications now have com.MyPackage.* prefix
OR use names Activity1 and Activity2
So you will have
com.MyPackage1.Activity1
// and
com.MyPackage2.Activity1
Then you can use this code, to start Activity1 in MyPackage2 from MyPackage1.
// in file com.MyPackage1.Activity1
Intent intent = new Intent();
intent.setComponent(new ComponentName("com.MyPackage2", "com.MyPackage2.Activity1"));
startActivity(intent);
And your AndroidManifest.xml files should look like this:
first
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name="com.MyPackage1.Activity1"
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>
second
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name="com.MyPackage2.Activity1"
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>
see related SO question:
How to start activity in another application?

Related

Trying to make a specific activity the main one

I am trying to make login screen the main activity however i receive the error 'activity must be exported or contain an intent filter'. I have also selected it to run from that activity in the Run-Edit configurations settings

Please close the activity tag after intent-filter as:
<activity
android:name=".LoginActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
Did that work for you ?

You just need to wrap intent-filter inside LoginActivity tag
<activity
android:name=".LoginActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

You are closing the <activity> tag right on declaration, the intent filter must be inside the node
<activity ... >
<intent filter ...
</activity>
I added a snippet of code cause you posted a image of code and actually is a reason for dowvoting.

Implicit Intent not being called

I am trying to use Implicit intent to launch an activity within the same application and for an activity of another application(my other application, not the native one), but couldn't succeed in any of the cases.
Here is my sample code for the first part (i.e. to launch an activity within the same application):
Inside Activity TESTActivity
Intent intent = new Intent();
intent.setAction("com.myapp.game.myimplicit_action");
startActivity(intent);
and here is my manifest file declaration for some activity say 'ImplicitActivity' with the same action:
<activity
android:name=".TESTActivity"
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=".ImplicitActivity">
<intent-filter>
<action android:name="com.myapp.test.myimplicit_action" />
</intent-filter>
</activity>
Both the activities TESTActivity and ImplicitActivity are in the same application under same package. Still my ImplicitActivity activity is not getting called.

I have figured out the problem. Posting the answer for the others facing the same problem.
We need to add Default Category in order to make Implicit intents work. So here is the correct manifest entry for the same activity :
<activity
android:name=".TESTActivity"
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=".ImplicitActivity">
<intent-filter>
<action android:name="com.myapp.test.myimplicit_action" />
<category android:name="android.intent.category.DEFAULT" />
</intent-filter>
</activity>

What does it mean "No Launcher activity found!"

I am writing a simple program of Android, and getting these no errors, I don't know what they are. My program is right, but showing not output.
I think it is because of these two lines:
[2005-01-06 19:56:38 - my_Android] No Launcher activity found!
[2005-01-06 19:56:38 - my_Android] The launch will only sync the application package on the device!

Here's an example from AndroidManifest.xml. You need to specify the MAIN and LAUNCHER in the intent filter for the activity you want to start on launch
<application android:label="#string/app_name" android:icon="#drawable/icon">
<activity android:name="ExampleActivity"
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>

Multiple action tags in a single intent-filter tag will also cause the same error.

Like Gusdor said above, "Multiple action tags in a single intent-filter tag will also cause the same error." (Give him the credit! I could just kiss Gusdor for this!)
I didn't find any docs for this fact!
I had added a new (USB) action and being clever, I lumped it in the same intent-filter. And it broke the launch.
Like Gusdor said, one intent filter, one action!
Apparently each action should go in its own intent filter.
It should look like this...
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<intent-filter>
<action android:name="android.hardware.usb.action.USB_DEVICE_ATTACHED" />
</intent-filter>
When I did this, WAZOO! it worked!

Do you have an activity set up the be the launched activity when the application starts?
This is done in your Manifest.xml file, something like:
<activity android:name=".Main" android:label="#string/app_name"
android:screenOrientation="portrait">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

Check your manifest.xml. Make sure you have the category LAUNCHER there.
<activity android:name=".myActivity"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>

It means you didn't specify an Activity for Android to launch as the default when the app opens from the launcher. You have to add an Intent Filter in the Manifest for the Activity you would like to act as the default when the app is being launched.
Read http://developer.android.com/guide/topics/intents/intents-filters.html#ccases for more details.

I fixed the problem by adding activity block in the application tag. I created the project using wizard, I don't know why my AdroidManifest.xml file was not containing application block? I added the application block:
<application
android:icon="#drawable/ic_launcher"
android:label="#string/app_name" >
<activity
android:name=".ToDoListActivity"
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>
And I get the desired output on the emulator.

As has been pointed out, this error is likely caused by a missing or incorrect intent-filter.
I would just like to add that this error also shows up if you set android:exported="false" on your launcher activity (in the manifest).

I had this same problem and it turns out I had a '\' instead of a '/' in the xml tag. It still gave the same error but just due to a syntax problem.

If you are using the standard eclipse IDE provided by google for Android development, you can check the "Launcher Activity" check-box while creating a new Activity. Please find below:

In Eclipse when can do this:
But it is preferable make the corresponding changes inside the Android manifest file.

You missed in specifying the intent filter elements in your manifest file.Manifest file is:
<application android:label="#string/app_name" android:icon="#drawable/icon">
<activity android:name="Your Activity Name"
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>
Add and check this correctly. Hope this will help..

Manifest is case sensitive, so please compare this lines for any case mismatch especially the word MAIN in:
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />

You can add launcher to activity in eclipse manifest visual editor:

MAIN will decide the first activity that will used when the application will start.
Launcher will add application in the application dashboard.
If you have them already and you are still getting the error message but maybe its because you might be using more than more category or action in an intent-filter. In an intent filter there can only be one such tag. To add another category, put it in another intent filter, like the following
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
<!--
TODO - Add necessary intent filter information so that this
Activity will accept Intents with the
action "android.intent.action.VIEW" and with an "http"
schemed URL
-->
<intent-filter>
<action android:name="android.intent.action.VIEW" />
<data android:scheme="http" />
<category android:name="android.intent.category.BROWSABLE" />
</intent-filter>

just add this to your aplication tag in AndroidManifest.xml file
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
and also edit the uses-sdk tag from android:targetSdkVersion="16" to 17
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />

You have not included Launcher intent filter in activity you want to appear first, so it does not know which activity to start when application launches, for this tell the system by including launcher filter intent in manifest.xml

How do I start my app from my other app?

How do I start my app from my other app? (they will not be package together)
--update
Manifest of the second app:
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.helloandroid"
android:versionCode="1"
android:versionName="1.0">
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name=".HelloAndroid"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
<category android:name="android.intent.category.HOME"/>
<category android:name="android.intent.category.DEFAULT"/>
</intent-filter>
</activity>
<activity android:name=".HelloAndroid">
<intent-filter>
<action android:name="com.example.helloandroid.HelloAndroid" />
</intent-filter>
</activity>
</application>
</manifest>
I calling it with:
startActivity(new Intent("com.example.helloandroid.HelloAndroid"));
and it throws:
07-16 15:11:01.455: ERROR/Desktop(610): android.content.ActivityNotFoundException: No Activity found to handle Intent { act=com.example.helloandroid.HelloAndroid }
Ralated:
How to launch android applications from another application

In the first app, you will have to modify the AndroidManifest.xml. Specifically, you are going to add a custom action into the intent-filter of the activity that you want to launch from somewhere:
<activity android:name="FirstApp">
<intent-filter>
<action android:name="com.example.foo.bar.YOUR_ACTION" />
</intent-filter>
</activity>
Then, in your second app you use that action to start the activity:
startActivity(new Intent("com.example.foo.bar.YOUR_ACTION"));
With regards to your comments:
Looks like if I change the default name "android.intent.action.MAIN" I'm not able to run the app from the Eclipse in the Virtual Device
Keep in mind you can have as many actions as you want... for instance:
<activity android:name="FirstApp">
<intent-filter>
<action android:name="com.example.foo.bar.YOUR_ACTION" />
<action android:name="android.intent.action.MAIN" />
</intent-filter>
</activity>

This questions seems similar to one I answered earlier today.
If you just want to start like you started it from the launcher:
Intent intent = new Intent("android.intent.action.MAIN");
intent.setComponent(new ComponentName( "PACKAGE NAME", "CLASS" ));
startActivity(intent);

Too many Activities being started when launching an Android Application

I am confirming about creating activity.
My Manifest.xml is like this :
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name=".FirstActivity"
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=".SecondActivity"
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=".ThirdActivity"
android:label="#string/app_name">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
You can see property action android:name= property is "android.intent.action.MAIN" and
category android:name= is "android.intent.category.LAUNCHER" for all activities.
When the application starts up, it calls FirstActivity.
Then calls useless Activity such as ThirdActivity or SecondActivity.
In this case, is my manifest.xml correct?
Or, do I need to set another property to Second and Third activity?
If so, what is that?
I wonder manifest.xml file is right for my case.
Please advise.

Try this config:
<application android:icon="#drawable/icon" android:label="#string/app_name">
<activity android:name=".FirstActivity" 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=".SecondActivity" android:label="#string/app_name">
<intent-filter>
</intent-filter>
</activity>
<activity android:name=".ThirdActivity" android:label="#string/app_name">
<intent-filter>
</intent-filter>
</activity>

Think of an Intent as message used to start an Activity to do something. So I can create an Intent to view a web page and an application with an Activity which knows how to view a web page - most likely the browser - can intercept his Intent as act on it.
You tell Android which Activities can act on which Intents using the <intent-filter> part of your Manifest.
The MAIN Intent is a special one. This is sent to an application when it is launched and basically it says "Go!" So the Activity which shoud be displayed first needs to intercept this by having a correctly defined <intent-filter>.
As you had all three Activities with MAIN in their filter they all responded to the request to start your application. So you should have that <intent-filter> only for FirstActivity.

One of the other problems with using
<category android:name="android.intent.category.LAUNCHER" /> for more than one activity is that the Phone's launcher menu will display more than one icon...
From the docs:
CATEGORY_LAUNCHER The activity can
be the initial activity of a task and
is listed in the top-level application
launcher.

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