ClassCastException ContentFrameLayout androidx vs. support.v7 in system app

Question

Strange Exception I am getting on a system app when I am using just FrameLayout in my SampleActivity.

Caused by: java.lang.ClassCastException: androidx.appcompat.widget.ContentFrameLayout cannot be cast to android.support.v7.widget.ContentFrameLayout
05-22 08:41:05.357 10520 10520 E AndroidRuntime: at android.support.v7.app.AppCompatDelegateImpl.createSubDecor(AppCompatDelegateImpl.java:685)
05-22 08:41:05.357 10520 10520 E AndroidRuntime: at android.support.v7.app.AppCompatDelegateImpl.ensureSubDecor(AppCompatDelegateImpl.java:516)
05-22 08:41:05.357 10520 10520 E AndroidRuntime: at android.support.v7.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:464)
05-22 08:41:05.357 10520 10520 E AndroidRuntime: at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:140)
05-22 08:41:05.357 10520 10520 E AndroidRuntime: at com.sample.SampleActivity.onCreate(SampleActivity.java:98)

So I looked into the source code of AppCompatDelegateImpl present here : AppCompatDelegateImpl

imports in SampleActivity.java:

import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;

While this class is part of android appcompat.v7 but internally it is importing androidx.appcompat.widget.ContentFrameLayout Does it imply that appcompat.v7 internally use androidx dependencies ? If yes, then why I am getting this exception ?

Note: Please avoid giving gradle based solutions since it is a system app.

@Basi It's a system application not the regular one, so it doesn't have gradle. — TheLittleNaruto, May 23 '19 at 09:39
Share the full code of your activity. If possible share the repository link. — Belal Khan, May 23 '19 at 12:33
Sorry that I can't do. You can ask me any specific code you're looking for, I'll share. @BelalKhan — TheLittleNaruto, May 23 '19 at 12:38
Then atleast post the full activity code here. Or the line where you are trying to make a cast. — Belal Khan, May 24 '19 at 03:06
@Belal Consider reading the question and the error log. I am nowhere using that ContentFrameLayout. — TheLittleNaruto, May 24 '19 at 04:46

score 3 · Accepted Answer · answered Jun 22 '19 at 16:13

3

Fix was to include androidx dependencies in Android.mk file.

Also had to change all import of support library classes to androidx as suggested in Android developer site: https://developer.android.com/jetpack/androidx/migrate

answered Jun 22 '19 at 16:13

TheLittleNaruto

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score 1 · Answer 2 · answered May 23 '19 at 09:34

1

Go to gradle.properties file and make sure

android.useAndroidX=false

If you set this to true, android plugin will use AndroidX Library instead of Support Library. Furthermore, if you're unable to find useAndroidX in gradle.properties, try adding it and perform gradle sync.

answered May 23 '19 at 09:34

Bugs 404

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@TheLittleNaruto The **ContentFrameLayout** you have inside SampleActivity is part of [androidx.appcompat.widget](https://android.googlesource.com/platform/frameworks/support/+/master/v7/appcompat/src/main/java/androidx/appcompat/widget/ContentFrameLayout.java). The **ContentFrameLayout** you need is inside [android.support.v7.widget](https://android.googlesource.com/platform/frameworks/support/+/8c3f757/v7/appcompat/src/android/support/v7/widget/ContentFrameLayout.java). Try using `import android.widget.FrameLayout;` and see if it links to support library. – Bugs 404 May 23 '19 at 10:07
I am using this FrameLayout only. – TheLittleNaruto May 23 '19 at 10:31

score 0 · Answer 3 · answered May 23 '19 at 09:09

0

Update your import statements. You're using class with same name but from different packages.

answered May 23 '19 at 09:09

Said

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What do you mean ? Please note that I am nowhere using "ContentFrameLayout" – TheLittleNaruto May 23 '19 at 09:12

ClassCastException ContentFrameLayout androidx vs. support.v7 in system app

3 Answers3