The application's default package is "example.app".
and the target activity's package is "ex开发者_Python百科ample.app.abc".
Calling startActivity() for "example.app.abc.TheActivity" in java code just works,
but specifying it on preference.xml doesn't work:
<PreferenceScreen android:key="key"
android:title="@string/title"
>
<intent android:action="android.intent.action.MAIN"
android:targetPackage="example.app.abc"
android:targetClass="TheActivity"
/>
</PreferenceScreen>
I tried android:targetClass="example.app.abc.TheActivity" but it doesn't work too.
Is it impossible to start an activity of non-default package, in preference?
I just ran into the same problem when trying to use a custom preference screen from a library project for the AccountManager account settings. No matter how I tried to tweak the targetPackage and targetClass attributes, it would throw an exception (except, since it's an account, it crashes the phone).
I think we'll just have to assume this is an Android limitation. It's clumsy, but all you really need to do is declare a wrapper class for the activity within your application's namespace:
public class MyPreferences extends ActualPreferences {
}
Declare it in your AndroidManifest.xml
<activity android:name=".MyPreferences"/>
Then you can specify the class in your intent
<intent android:targetPackage="com.my.package"
android:targetClass="com.my.package.MyPreferences" />
By the way, the syntax is extremely fussy, at least for account preferences. All these variations fail:
<!-- fails --> <intent android:targetClass="com.my.package.MyPreferences" />
<!-- fails --> <intent android:targetClass="MyPreferences"
android:targetPackage="com.my.package"/>
<!-- fails --> <intent android:targetClass=".MyPreferences"
android:targetPackage="com.my.package"/>
<!-- fails --> <intent android:targetClass="settings.MyPreferences"
android:targetPackage="com.my.package"/>
<!-- fails --> <intent android:targetClass=".settings.MyPreferences"
android:targetPackage="com.my.package"/>
<!-- fails --> <intent android:targetClass="com.my.other.package.MyPreferences"
android:targetPackage="com.my.package"/>
The critical factor is apparently that the android:targetPackage
attribute matches the application package. If you want, you can put the activity in a sub-package. This works:
<intent android:targetPackage="com.my.package"
android:targetClass="com.my.package.settings.MyPreferences" />
as already said its not working with libraries. Do it programatically, something like this:
preference_my_pref.setOnPreferenceClickListener(new OnPreferenceClickListener() {
public boolean onPreferenceClick(Preference preference) {
Intent intent = new Intent(MyActivity.this, ActivityToStart.class);
startActivity(intent);
return true;
}
});
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