Can not find attribute app:useSimpleSummaryProvider

Question

I want to update my preference summary and I found something called SimpleSummaryProvider here. But In my case, it's saying that cannot find attribute app:useSimpleSummaryProvider and in Java code, it's saying, cannot resolve SummaryProvider class. My app level build Gradle dependencies are as-

implementation fileTree(include: ['*.jar'], dir: 'libs')
implementation 'com.android.support:appcompat-v7:28.0.0'
androidTestImplementation 'junit:junit:4.12'
androidTestImplementation 'com.android.support:support-annotations:28.0.0'
androidTestImplementation 'com.android.support.test:runner:1.0.2'
androidTestImplementation 'com.android.support.test:rules:1.0.2'
implementation 'com.android.support:recyclerview-v7:28.0.0'
implementation 'com.android.support.constraint:constraint-layout:1.1.3'
implementation 'com.android.support:design:28.0.0'
implementation 'com.android.support:preference-v7:28.0.0'

I don't know if I am missing something. I will appreciate any help

Answer 1

app:useSimpleSummaryProvider is newly added in the androidx.preference 1.1.0-alpha01 according to AndroidX release notes(search app:useSimpleSummaryProvider in the page).

So you need to migrate to AndroidX and update to the latest alpha version of androidx.