Cardview shadow for ImageView

Question

(1 screenshot - ImageView visibility is visible, 2 screenshot - gone)

When using ImageView with CardView we can say that shadow isn't visible at all (especially on the smartphone display)

<android.support.v7.widget.CardView
    android:id="@+id/ImageViewWrapper"
    android:layout_width="0dp"
    android:layout_height="0dp"
    android:elevation="0dp"
    android:layout_margin="10dp"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:cardCornerRadius="6dp">

    <android.support.v7.widget.AppCompatImageView
        android:id="@+id/ImageView"
        android:visibility="visible"
        android:background="@color/black_1000"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_gravity="center_vertical"
        app:srcCompat="@drawable/ic_folder"/>

</android.support.v7.widget.CardView>

android:elevation doesn't make any effect (0dp, 5dp, or 20dp - nothing changes), so I just set it 0dp

Can we control this cardview shadow, make it stronger/bigger/thicker?

3 screenshot - here MX Player app example of video thumbnail ImageView (https://play.google.com/store/apps/details?id=com.mxtech.videoplayer.ad)

Update

I set app:cardElevation="7dp" and app:cardUseCompatPadding="true" No progress... and cardUseCompatPadding made my image height size smaller and now I have black bars at left/right

https://stackoverflow.com/questions/27599603/cardview-not-showing-shadow-in-android-l/33044134 — duggu, Mar 02 '18 at 19:45
Why are you using `android.support.v7.widget.AppCompatImageView` instead of `ImagefView` ?? Is there any reason? — Xenolion, Mar 02 '18 at 20:06
@Xenolion `ImageView` usually is always `AppCompatImageView`, but in some cases we have to explicitly set `AppCompatImageView` if, for example, using custom list item xml for RecyclerView and inflating like `View view = LayoutInflater.from(mContext).inflate(R.layout.list_item, parent, false);` — user924, Mar 02 '18 at 20:11
@Xenolion *AppCompatImageView will automatically be used when you use ImageView in your layouts and the top-level activity / dialog is provided by appcompat. You should only need to manually use this class when writing custom views.* https://developer.android.com/reference/android/support/v7/widget/AppCompatImageView.html — user924, Mar 02 '18 at 20:16
I have got it, thank you I have understood. But I think your image is on top of the card view. Try adding some padding in the cardview as a test? — Xenolion, Mar 02 '18 at 20:20
@Xenolion I just think CardView shadow is weak and visibility is good only if CardView's content not that filled and colored (like mine) — user924, Mar 02 '18 at 20:32

Xenolion · Accepted Answer · 2018-03-02T20:08:49.347

3

Use app:cardElevation="4dp"instead of android:elevation.

Also add this app:cardUseCompatPadding="true".

UPDATE

Also consider changing the CardView size to:

android:layout_width="wrap_content"
android:layout_height="wrap_content"

edited Mar 02 '18 at 20:08

answered Mar 02 '18 at 19:43

Xenolion

12,035
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updated question using `app:cardElevation="7dp" app:cardUseCompatPadding="true"`, no progress, and cardUseCompatPadding ruins image size – user924 Mar 02 '18 at 20:00
I have updated the answer! Also use `ImageView` instead of `AppCompatImageView`. and set adjustLayoutBounds to it. – Xenolion Mar 02 '18 at 20:10
ImageView == AppCompatImageView – user924 Mar 02 '18 at 20:13
I use layout constraints and I set specific size for my views, I can't use wrap_content... – user924 Mar 02 '18 at 20:14
changing value of `app:cardElevation` actually makes shadow bigger but it's so weak/transparent that we don't really see it very good.. As I understand we can't control shadow's transparent and color for CardView – user924 Mar 02 '18 at 20:36
But I dont think you have any grey layouts/view there! – Xenolion Mar 02 '18 at 20:38
what do you mean? – user924 Mar 03 '18 at 06:49
The shadow in `CardView` is just an illusion of grey colour thats when added looks like a shadow since it has a gradient. Infact you can make your own shadow without `CardView`! – Xenolion Mar 03 '18 at 09:48
1

It didn't help me at all – Vlad Alexeev Mar 14 '20 at 19:28

score 1 · Answer 2 · answered Mar 02 '18 at 19:47

1

Make sure enable hardware Acceleration

You can do it at application level:

<application android:hardwareAccelerated="true" ...>

Or activity level:

<application android:hardwareAccelerated="false">
    <activity ... />
    <activity android:hardwareAccelerated="true" />
</application>

Or Window level, view level, etc.

answered Mar 02 '18 at 19:47

Student222

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I believe it's enabled by default, anyway I tried to add `` but it didn't change anything, also I guess if it was disabled then shadow would not be visible at all – user924 Mar 02 '18 at 19:53
@user924 What is your minimum targeted android version? – Student222 Mar 02 '18 at 20:06
Android 4.1 (API level 16) – user924 Mar 02 '18 at 20:07

Cardview shadow for ImageView

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