Damn app crashes, finally solved error-while-inflating-CardView

Preface

(First, a smiley face) This problem has been bothering me for a long time. I searched all over with no results. The solutions I got were nothing more than that the AppCompact and CardView package versions were different, and so on, but I didn't have that problem at all. (Afraid they don't take my Gradle seriously?)

Problem

It's this kind of interface, using RecycleView and Cardview, but it doesn't work on SDK 23 and below. Official docs already state this component is supported down to SDK 9 or 10, anyway basically any android phone should work, yet it just doesn't. On SDK 24 and above there's no problem, my own phone has no problem, it's just on the emulator and a few old-version test devices, they all crash. I really want to strangle this Cardview..

Solution

Tonight I spent two hours looking things up, went through Google's official docs, downloaded a few official Samples, but didn't find any valuable solutions. Then I continued searching on Stack Overflow. Stack Overflow is really a programmer's essential helper for home and travel. Finally, hard work paid off, and I found fellow users who encountered the same problem as me.

These two answers were of reference value:

https://stackoverflow.com/questions/38132148/error-while-inflating-class-android-support-v7-widget-cardview

Try this it will help you remove this android:foreground="?android:attr/selectableItemBackground"

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:paddingLeft="4dp"
android:paddingRight="4dp"
android:paddingBottom="2dp">

<android.support.v7.widget.CardView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/cardview"
    card_view:cardBackgroundColor="@android:color/white"
    card_view:cardElevation="2dp"
    card_view:cardMaxElevation="2dp"
    card_view:cardUseCompatPadding="true">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">

....here i have a bunch of other layout elements
         </RelativeLayout>
    </android.support.v7.widget.CardView>
</LinearLayout>

This answer told me to delete android:foreground. I deleted it as instructed, but it still didn't work. However, using this on SDK 23 and below indeed has compatibility issues.

Then this one: https://stackoverflow.com/questions/28541920/error-when-inflating-cardview

From the official notes of appcompat v21

He told me to take a look at the official docs:

Why are there no ripples on pre-Lollipop? A lot of what allows RippleDrawable to run smoothly is Android 5.0’s new RenderThread. To optimize for performance on previous versions of Android, we've left RippleDrawable out for now.

When trying to use ripple-drawables, you get errors on pre-lollipop (that's why it says line 2, it's the xml drawable). Use a different folder (drawable-v21) for ripples and use selectors in your normal drawables if you want a difference for different states.

Official support is not coming soon, I believe, because lollipop has a dedicated render-thread that no other version has.

Meaning that android:stateListAnimator="@drawable/selector_elevation" doesn't work, it's not supported on older versions of the system.. And then new support is still coming soon? I don't believe it.

So in the end, I deleted both of these lines of code, and a touching scene appeared, it finally worked~~~ The deleted code, shit!

android:stateListAnimator="@drawable/selector_elevation"
android:foreground="?android:attr/selectableItemBackground"