Unable to instantiate activity ComponentInfo Exception

Question

My app can be started in two ways:

"Normally" via the launcher
As an Intent, when the user selects a contact from his address book

The first method works just fine. The main activity opens up, and the user can use the app. The second method however produces the following error/crash:

Unable to instantiate activity ComponentInfo{de.mystuff.myapp/de.mystuff.myapp.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "de.mystuff.myapp.MainActivity" on path: DexPathList[[zip file "/data/app/de.mystuff.myapp-1/base.apk"],nativeLibraryDirectories=[/data/app/de.mystuff.myapp-1/lib/arm, /data/app/de.mystuff.myapp-1/base.apk!/lib/armeabi-v7a, /vendor/lib, /system/lib]]

In my manifest I have declared the main activity as follows:

<activity android:name=".MainActivity" android:theme="@style/AppTheme">
            <intent-filter>
                <action android:name="android.intent.action.CALL" />
                <category android:name="android.intent.category.DEFAULT" />
                <action android:name="android.intent.action.CALL_PRIVILEGED" />
                <data android:scheme="tel" />
            </intent-filter>
        </activity>

And my activity's code looks like this:

[Activity (Label = "MyApp", MainLauncher = true, Icon = "@mipmap/ic_launcher")]
  public class MainActivity : Activity, SwipeRefreshLayout.IOnRefreshListener
  {
    AppSettings mAppSettings;

    ContactListViewAdapter mListViewAdapter;

    SwipeRefreshLayout mSwiper;

    protected override void OnCreate (Bundle savedInstanceState)
    {
      base.OnCreate (savedInstanceState);
      SetContentView (Resource.Layout.Main);

      // Do some other init stuff
    }
}

Sven-Michael Stübe Sven-Michael Stübe · Accepted Answer · 2016-08-22T22:10:56

You should avoid to mix up declarative style and manually writing the AndroidManifest.xml.

[Activity (Label = "MyApp", MainLauncher = true, Icon = "@mipmap/ic_launcher")] is generating a piece of code in the actual used (generated) AndroidManifest.xml that looks like:

<activity android:icon="@drawable/icon" android:label="AndroidApp1" android:name="md5c178831cd46fc53bebc42cf953f78ced.MainActivity">
  <intent-filter>
    <action android:name="android.intent.action.MAIN" />
    <category android:name="android.intent.category.LAUNCHER" />
  </intent-filter>
</activity>

and your code will be somewhere else. You can find the generated AndroidManifest.xml in the output folder .\obj\Debug\android.

Solution:

You can add your stuff via attributes like:

[Activity (Label = "MyApp", MainLauncher = true, Icon = "@mipmap/ic_launcher")]
[IntentFilter(
    new [] { Intent.ActionCall, "android.intent.action.CALL_PRIVILEGED" },
    Categories = new [] {Intent.CategoryDefault},
    DataScheme = "tel")]
public class MainActivity : Activity, SwipeRefreshLayout.IOnRefreshListener
{
    // ...
}

And remove the manual edits from your manifest file. The output will look like:

<activity android:icon="@drawable/icon" android:label="AndroidApp1" android:name="md5c178831cd46fc53bebc42cf953f78ced.MainActivity">
  <intent-filter>
    <action android:name="android.intent.action.MAIN" />
    <category android:name="android.intent.category.LAUNCHER" />
  </intent-filter>
  <intent-filter>
    <action android:name="android.intent.action.CALL" />
    <action android:name="android.intent.action.CALL_PRIVILEGED" />
    <category android:name="android.intent.category.DEFAULT" />
    <data android:scheme="tel" />
  </intent-filter>
</activity>

Unable to instantiate activity ComponentInfo Exception

2 Answers