remove shadow below AppBarLayout widget android

Question

When using AppBarLayout widget in design support library, a shadow appears on the bottom of the toolbar. How can I remove that shadow?

Answer 1

Simply use app:elevation="0dp" inside "AppBarLayout" to remove the shadow. It has always worked for me. Hope it works for you.

Answer 2

this problem only occurs when api version >= 21, try below codes:

appBar.setOutlineProvider(null); 

remember to check api version

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EDIT :

Below is the source code of setOutlineProvider.

   /**      * Sets the {@link ViewOutlineProvider} of the view, which generates the Outline that defines      * the shape of the shadow it casts, and enables outline clipping.      * <p>      * The default ViewOutlineProvider, {@link ViewOutlineProvider#BACKGROUND}, queries the Outline      * from the View's background drawable, via {@link Drawable#getOutline(Outline)}. Changing the      * outline provider with this method allows this behavior to be overridden.      * <p>      * If the ViewOutlineProvider is null, if querying it for an outline returns false,      * or if the produced Outline is {@link Outline#isEmpty()}, shadows will not be cast.      * <p>      * Only outlines that return true from {@link Outline#canClip()} may be used for clipping.      *      * @see #setClipToOutline(boolean)      * @see #getClipToOutline()      * @see #getOutlineProvider()      */     public void setOutlineProvider(ViewOutlineProvider provider) {         mOutlineProvider = provider;         invalidateOutline();     } 

It is said that If the ViewOutlineProvider is null, if querying it for an outline returns false, or if the produced Outline is {@link Outline#isEmpty()}, shadows will not be cast.

So, if you want to remove shadow, you'd better use this method instead of setting app:elevation. It seems like that changing the elevation to remove shadow is a kind of side effect. And changing the elevation may cause some other problems in some cases.