android studio app crashes when setting gradient background

Question

My app crashed immediately when I'm setting gradient background, if I'm not doing this then everything is working.

My activity_main.xml:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@drawable/gradient_background"
    tools:context="com.example.uytkownik.myapplication.MainActivity">

    <ProgressBar
        android:id="@+id/progressBar2"
        style="?android:attr/progressBarStyle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_centerVertical="true"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</RelativeLayout>

gradient_background.xml:

<?xml version="1.0" encoding="UTF-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item>
        <shape>
            <gradient
                android:startColor="@color/gradientColBeg"
                android:endColor="@color/gradientColEnd"
                android:angle="90"/>
        </shape>
    </item>
</selector>

colors.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="colorPrimary">#3F51B5</color>
    <color name="colorPrimaryDark">#303F9F</color>
    <color name="colorAccent">#000000</color>
    <color name="gradientColBeg">#FFF</color>
    <color name="gradientColEnd">#000</color>
</resources>

stack trace:

12/30 15:39:05: Launching app
$ adb install-multiple -r -t -p com.example.uytkownik.myapplication D:\Projekty\java\nauka\MyApplication\app\build\intermediates\split-apk\debug\slices\slice_0.apk D:\Projekty\java\nauka\MyApplication\app\build\outputs\apk\debug\app-debug.apk 
Split APKs installed
$ adb shell am start -n "com.example.uytkownik.myapplication/com.example.uytkownik.myapplication.MainActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Connected to process 16680 on device huawei-huawei_y560_l01-Q6VBBBB5B0520663
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
I/InstantRun: starting instant run server: is main process
V/HwPolicyFactory: : success to get AllImpl object and return....
V/HwWidgetFactory: : successes to get AllImpl object and return....
E/art: ClassLinker::FindClass not found:Landroid/widget/ViewStub;
E/art: ClassLinker::FindClass not found:Landroid/webkit/ViewStub;
E/art: ClassLinker::FindClass not found:Landroid/app/ViewStub;
W/ResourceType: Failure getting entry for 0x7f020053 (t=1 e=83) (error -75)
D/AndroidRuntime: Shutting down VM
E/AndroidRuntime: FATAL EXCEPTION: main
                  Process: com.example.uytkownik.myapplication, PID: 16680
                  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.uytkownik.myapplication/com.example.uytkownik.myapplication.MainActivity}: android.view.InflateException: Binary XML file line #2: Error inflating class android.widget.RelativeLayout
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2345)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2407)
                      at android.app.ActivityThread.access$700(ActivityThread.java:155)
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1317)
                      at android.os.Handler.dispatchMessage(Handler.java:102)
                      at android.os.Looper.loop(Looper.java:135)
                      at android.app.ActivityThread.main(ActivityThread.java:5298)
                      at java.lang.reflect.Method.invoke(Native Method)
                      at java.lang.reflect.Method.invoke(Method.java:372)
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:911)
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:706)
                   Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class android.widget.RelativeLayout
                      at android.view.LayoutInflater.createView(LayoutInflater.java:633)
                      at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:55)
                      at com.android.internal.policy.impl.HwPhoneLayoutInflater.onCreateView(HwPhoneLayoutInflater.java:75)
                      at android.view.LayoutInflater.onCreateView(LayoutInflater.java:682)
                      at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:741)
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:482)
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:414)
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:365)
                      at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:378)
                      at android.app.Activity.setContentView(Activity.java:2160)
                      at com.example.uytkownik.myapplication.MainActivity.onCreate(MainActivity.java:17)
                      at android.app.Activity.performCreate(Activity.java:6039)
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106)
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298)
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2407) 
                      at android.app.ActivityThread.access$700(ActivityThread.java:155) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1317) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:135) 
                      at android.app.ActivityThread.main(ActivityThread.java:5298) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at java.lang.reflect.Method.invoke(Method.java:372) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:911) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:706) 
                   Caused by: java.lang.reflect.InvocationTargetException
                      at java.lang.reflect.Constructor.newInstance(Native Method)
                      at java.lang.reflect.Constructor.newInstance(Constructor.java:288)
                      at android.view.LayoutInflater.createView(LayoutInflater.java:607)
                      at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:55) 
                      at com.android.internal.policy.impl.HwPhoneLayoutInflater.onCreateView(HwPhoneLayoutInflater.java:75) 
                      at android.view.LayoutInflater.onCreateView(LayoutInflater.java:682) 
                      at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:741) 
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:482) 
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:414) 
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:365) 
                      at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:378) 
                      at android.app.Activity.setContentView(Activity.java:2160) 
                      at com.example.uytkownik.myapplication.MainActivity.onCreate(MainActivity.java:17) 
                      at android.app.Activity.performCreate(Activity.java:6039) 
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) 
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298) 
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2407) 
                      at android.app.ActivityThread.access$700(ActivityThread.java:155) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1317) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:135) 
                      at android.app.ActivityThread.main(ActivityThread.java:5298) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at java.lang.reflect.Method.invoke(Method.java:372) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:911) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:706) 
                   Caused by: android.content.res.Resources$NotFoundException: Resource "com.example.uytkownik.myapplication:drawable/gradient_background" (7f020053)  is not a Drawable (color or path): TypedValue{t=0x1/d=0x7f020053 a=-1 r=0x7f020053}
                      at android.content.res.Resources.loadDrawableForCookie(Resources.java:2462)
                      at android.content.res.Resources.loadDrawable(Resources.java:2400)
                      at android.content.res.HwResources.loadDrawable(HwResources.java:609)
                      at android.content.res.TypedArray.getDrawable(TypedArray.java:785)
                      at android.view.View.<init>(View.java:3747)
                      at android.view.ViewGroup.<init>(ViewGroup.java:498)
                      at android.widget.RelativeLayout.<init>(RelativeLayout.java:249)
                      at android.widget.RelativeLayout.<init>(RelativeLayout.java:245)
                      at android.widget.RelativeLayout.<init>(RelativeLayout.java:241)
                      at java.lang.reflect.Constructor.newInstance(Native Method) 
                      at java.lang.reflect.Constructor.newInstance(Constructor.java:288) 
                      at android.view.LayoutInflater.createView(LayoutInflater.java:607) 
                      at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:55) 
                      at com.android.internal.policy.impl.HwPhoneLayoutInflater.onCreateView(HwPhoneLayoutInflater.java:75) 
                      at android.view.LayoutInflater.onCreateView(LayoutInflater.java:682) 
                      at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:741) 
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:482) 
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:414) 
                      at android.view.LayoutInflater.inflate(LayoutInflater.java:365) 
                      at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:378) 
                      at android.app.Activity.setContentView(Activity.java:2160) 
                      at com.example.uytkownik.myapplication.MainActivity.onCreate(MainActivity.java:17) 
                      at android.app.Activity.performCreate(Activity.java:6039) 
                      at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1106) 
                      at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2298) 
                      at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2407) 
                      at android.app.ActivityThread.access$700(ActivityThread.java:155) 
                      at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1317) 
                      at android.os.Handler.dispatchMessage(Handler.java:102) 
                      at android.os.Looper.loop(Looper.java:135) 
                      at android.app.ActivityThread.main(ActivityThread.java:5298) 
                      at java.lang.reflect.Method.invoke(Native Method) 
                      at java.lang.reflect.Method.invoke(Method.java:372) 
                      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:911) 
                      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:706) 
I/Process: Sending signal. PID: 16680 SIG: 9
Application terminated.

I'm new to android studio, and I don't know what can cause that exception. I will apreciate any help, thanks very much!

Answer 1

everything is ok! you have to tell the type of the gradient else it crashes!

<?xml version="1.0" encoding="UTF-8"?>
    <selector xmlns:android="http://schemas.android.com/apk/res/android">
        <item>
            <shape>
                <gradient
                    android:startColor="@color/gradientColBeg"
                    android:endColor="@color/gradientColEnd"
                    android:angle="90"
                    android:type="linear"
    />
            </shape>
        </item>
    </selector>

Answer 2

I have tested your drawable code and it's working fine so You got to make sure that you are not doing the following things which may cause the app to crash.

1. you are not putting gradient_background in the drawable-v21 folder instead of drawable only and running in older the version devices.

2. you are not changing the theme to something else and applying something else in styles or manifest.