Question

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>

Answer 1

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?