Can Gradientcolor Be Used to Define a Gradient for a Fill or Stroke Entirely in Xml

Can GradientColor be used to define a gradient for a fill or stroke entirely in XML?

I've finally made it work. Gradient color feature is not supported yet in Android Studio (current ver is 2.2) so it doesn't help you with autocomplete but marks gradient tag as error instead. Nevertheless, the feature does actually work, I've tested it successfully on Nexus 5X / API 24. Of course, you have to use an API 24+ device because otherwise this feature is not supported by OS.

First, you need to add color resource file like this:

<?xml version="1.0" encoding="utf-8"?>
<gradient xmlns:android="http://schemas.android.com/apk/res/android"
    android:startColor="#FFFFFF"
    android:centerColor="#0000FF"
    android:endColor="#00FFFF"
    android:angle="145"
    android:startX="30"
    android:endX="70"
    android:startY="30"
    android:endY="70"
    android:type="linear"/>

Please pay attention to start/end parameters as I found they are essential for vector gradients.

Place this file into res/color folder under some name. I've named it gradient.xml so the full path is res/color/gradient.xml. After that you can refer to this resource in color attributes, including vector path colors:

<?xml version="1.0" encoding="utf-8"?>
<vector xmlns:android="http://schemas.android.com/apk/res/android"
    android:width="120dp"
    android:height="120dp"
    android:viewportWidth="120.0"
    android:viewportHeight="120.0">

    <path
        android:name="play_triangle"
        android:pathData="M 30 30 L 30 90 L 80 60 z"
        android:strokeWidth="10"
        android:strokeColor="@color/gradient"/>

</vector>

Notice the reference to gradient color resource in strokeColor. Hope this helps!

How to make gradient background in android

You can create this 'half-gradient' look by using an xml Layer-List to combine the top and bottom 'bands' into one file. Each band is an xml shape.

See this previous answer on SO for a detailed tutorial: Multi-gradient shapes.

Color of Primary Dark to be Gradient

This will break starting from Android N (API 25) with the following error:

android.content.res.Resources$NotFoundException: Can't find ColorStateList from drawable resource ID...

It's pretty much the same error as this SO issue, and as pointed out by an answer, the error/crash is intentional.
I guess the reason is because the Android gods are now being strict with not letting you use something other than color for a @color resource. So, this is definitely not the "right way" to do it.

A workaround would be to use a custom toolbar where you can use the drawable gradient for the background.

I did try this other solution on SO, which claims to work for API 24+, but alas it breaks in API 25 & 26. It does seem like something Android should simply work with but just doesn't..

Set gradient on stroke android

You should do something like this. Use layer-list with 2 shapes. First one is for gradient stroke and second one is for solid.

<?xml version="1.0" encoding="UTF-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item>
        <shape android:shape="oval" >
            <gradient
                android:angle="360"
                android:startColor="#543456"
                android:endColor="#ff00b5"
                android:type="linear" />
            <size android:width="24dp"
                  android:height="24dp"/>
        </shape>
    </item>

    <item
        android:bottom="2dp"
        android:left="2dp"
        android:right="2dp"
        android:top="2dp">
        <shape android:shape="oval" >
            <solid android:color="#fff" />
        </shape>
    </item>

</layer-list>

This code looks like this

CardView: How do I add a gradient background while maintaining the radius

If I may ask, are you per-chance testing/running on a pre-lollipop Android device? Your code seems to work as you desire (curved corners showing with the gradient) except on Android 4.

To achieve the desired result on pre-lollipop devices, you can add <corners android:radius="4dp" /> to your @drawable/btn_gradient file, (you would have to set the corner radius to match the CardView's cardCornerRadius.

How to set a gradient background to a Material Button?

To use a custom drawable background with the MaterialButton you can use the android:background attribute:

<MaterialButton
    app:backgroundTint="@null"
    android:background="@drawable/bkg_button_gradient"
    ... />

NOTE: It requires at least the version 1.2.0-alpha06

Currently it is very important to add app:backgroundTint="@null" to avoid that the custom background doesn't get tinted by default with the backgroundTint color.

With lower versions of the Material Components Library you have to use an AppCompatButton.

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