Only Showing Background Color when run on Emulator

Question

I wrote my first android application, when I am running the app I can only see the background colour in emulator. Since I am new to android development, I am not able to figure out the error. Can you help me please? Links to tutorials will also be helpful.

Here is my console output.

08/18 11:05:40: Launching app
$ adb shell am start -n "com.example.myapplicationh81first/com.example.myapplicationh81first.view.activity.BoticActivity" -a android.intent.action.MAIN -c android.intent.category.LAUNCHER
Client not ready yet..Waiting for process to come online
Connected to process 21093 on device samsung-sm_a510f-33006d9a1314a263
Capturing and displaying logcat messages from application. This behavior can be disabled in the "Logcat output" section of the "Debugger" settings page.
E/Zygote: v2
I/libpersona: KNOX_SDCARD checking this for 10176
    KNOX_SDCARD not a persona
E/Zygote: accessInfo : 0
W/SELinux: SELinux selinux_android_compute_policy_index : Policy Index[2],  Con:u:r:zygote:s0 RAM:SEPF_SECMOBILE_7.0_0007, [-1 -1 -1 -1 0 1]
I/SELinux: SELinux: seapp_context_lookup: seinfo=untrusted, level=s0:c512,c768, pkgname=com.example.myapplicationh81first 
I/art: Late-enabling -Xcheck:jni
D/TimaKeyStoreProvider: TimaKeyStore is not enabled: cannot add TimaSignature Service and generateKeyPair Service
W/ActivityThread: Application com.example.myapplicationh81first can be debugged on port 8100...
W/System: ClassLoader referenced unknown path: /data/app/com.example.myapplicationh81first-1/lib/arm
I/InstantRun: starting instant run server: is main process
W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter androidx.vectordrawable.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable
I/art: Rejecting re-init on previously-failed class java.lang.Class<androidx.core.view.ViewCompat$2>: java.lang.NoClassDefFoundError: Failed resolution of: Landroid/view/View$OnUnhandledKeyEventListener;
        at void androidx.core.view.ViewCompat.setBackground(android.view.View, android.graphics.drawable.Drawable) (ViewCompat.java:2559)
        at void androidx.appcompat.widget.ActionBarContainer.<init>(android.content.Context, android.util.AttributeSet) (ActionBarContainer.java:63)
        at java.lang.Object java.lang.reflect.Constructor.newInstance0!(java.lang.Object[]) (Constructor.java:-2)
        at java.lang.Object java.lang.reflect.Constructor.newInstance(java.lang.Object[]) (Constructor.java:430)
        at android.view.View android.view.LayoutInflater.createView(java.lang.String, java.lang.String, android.util.AttributeSet) (LayoutInflater.java:652)
        at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:794)
        at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet) (LayoutInflater.java:734)
        at void android.view.LayoutInflater.rInflate(org.xmlpull.v1.XmlPullParser, android.view.View, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:865)
        at void android.view.LayoutInflater.rInflateChildren(org.xmlpull.v1.XmlPullParser, android.view.View, android.util.AttributeSet, boolean) (LayoutInflater.java:828)
        at android.view.View android.view.LayoutInflater.inflate(org.xmlpull.v1.XmlPullParser, android.view.ViewGroup, boolean) (LayoutInflater.java:525)
        at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup, boolean) (LayoutInflater.java:427)
        at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup) (LayoutInflater.java:378)
        at android.view.ViewGroup androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:739)
        at void androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:649)
        at void androidx.appcompat.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:542)
        at void androidx.appcompat.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:161)
        at void com.example.myapplicationh81first.view.activity.BoticActivity.onCreate(android.os.Bundle) (BoticActivity.java:17)
        at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:6955)
        at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1126)
        at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2927)
        at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:3045)
        at void android.app.ActivityThread.-wrap14(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
        at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1642)
        at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:102)
        at void android.os.Looper.loop() (Looper.java:154)
        at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6776)
        at java.lang.Object java.lang.reflect.Method.invoke!(java.lang.Object, java.lang.Object[]) (Method.java:-2)
        at void com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run() (ZygoteInit.java:1496)
        at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:1386)
    Caused by: java.lang.ClassNotFoundException: Didn't find class "android.view.View$OnUnhandledKeyEventListener" on path: DexPathList[[zip file "/data/app/com.example.myapplicationh81first-1/base.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_lib_dependencies_apk.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_lib_slice_0_apk.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_lib_slice_1_apk.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_lib_slice_2_apk.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_lib_slice_3_apk.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_lib_slice_4_apk.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_lib_slice_5_apk.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_lib_slice_6_apk.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_lib_slice_7_apk.apk", zip file "/data/app/com.example.myapplicationh81first-1/split_
        at java.lang.Class dalvik.system.BaseDexClassLoader.findClass(java.lang.String) (BaseDexClassLoader.java:56)
        at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String, boolean) (ClassLoader.java:380)
        at java.lang.Class java.lang.ClassLoader.loadClass(java.lang.String) (ClassLoader.java:312)
        at void androidx.core.view.ViewCompat.setBackground(android.view.View, android.graphics.drawable.Drawable) (ViewCompat.java:2559)
        at void androidx.appcompat.widget.ActionBarContainer.<init>(android.content.Context, android.util.AttributeSet) (ActionBarContainer.java:63)
        at java.lang.Object java.lang.reflect.Constructor.newInstance0!(java.lang.Object[]) (Constructor.java:-2)
        at java.lang.Object java.lang.reflect.Constructor.newInstance(java.lang.Object[]) (Constructor.java:430)
        at android.view.View android.view.LayoutInflater.createView(java.lang.String, java.lang.String, android.util.AttributeSet) (LayoutInflater.java:652)
        at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:794)
        at android.view.View android.view.LayoutInflater.createViewFromTag(android.view.View, java.lang.String, android.content.Context, android.util.AttributeSet) (LayoutInflater.java:734)
        at void android.view.LayoutInflater.rInflate(org.xmlpull.v1.XmlPullParser, android.view.View, android.content.Context, android.util.AttributeSet, boolean) (LayoutInflater.java:865)
        at void android.view.LayoutInflater.rInflateChildren(org.xmlpull.v1.XmlPullParser, android.view.View, android.util.AttributeSet, boolean) (LayoutInflater.java:828)
        at android.view.View android.view.LayoutInflater.inflate(org.xmlpull.v1.XmlPullParser, android.view.ViewGroup, boolean) (LayoutInflater.java:525)
        at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup, boolean) (LayoutInflater.java:427)
        at android.view.View android.view.LayoutInflater.inflate(int, android.view.ViewGroup) (LayoutInflater.java:378)
        at android.view.ViewGroup androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor() (AppCompatDelegateImpl.java:739)
        at void androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor() (AppCompatDelegateImpl.java:649)
        at void androidx.appcompat.app.AppCompatDelegateImpl.setContentView(int) (AppCompatDelegateImpl.java:542)
        at void androidx.appcompat.app.AppCompatActivity.setContentView(int) (AppCompatActivity.java:161)
        at void com.example.myapplicationh81first.view.activity.BoticActivity.onCreate(android.os.Bundle) (BoticActivity.java:17)
        at void android.app.Activity.performCreate(android.os.Bundle) (Activity.java:6955)
        at void android.app.Instrumentation.callActivityOnCreate(android.app.Activity, android.os.Bundle) (Instrumentation.java:1126)
        at android.app.Activity android.app.ActivityThread.performLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent) (ActivityThread.java:2927)
I/art:     at void android.app.ActivityThread.handleLaunchActivity(android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:3045)
        at void android.app.ActivityThread.-wrap14(android.app.ActivityThread, android.app.ActivityThread$ActivityClientRecord, android.content.Intent, java.lang.String) (ActivityThread.java:-1)
        at void android.app.ActivityThread$H.handleMessage(android.os.Message) (ActivityThread.java:1642)
        at void android.os.Handler.dispatchMessage(android.os.Message) (Handler.java:102)
        at void android.os.Looper.loop() (Looper.java:154)
        at void android.app.ActivityThread.main(java.lang.String[]) (ActivityThread.java:6776)
        at java.lang.Object java.lang.reflect.Method.invoke!(java.lang.Object, java.lang.Object[]) (Method.java:-2)
        at void com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run() (ZygoteInit.java:1496)
        at void com.android.internal.os.ZygoteInit.main(java.lang.String[]) (ZygoteInit.java:1386)
D/TextView: setTypeface with style : 0
D/TextView: setTypeface with style : 0
D/Choreographer: init sf_choreo_doframe   debug_Level : 0x4f4cdebug_game_running : false
D/ViewRootImpl@9596aae[BoticActivity]: ThreadedRenderer.create() translucent=false
D/InputTransport: Input channel constructed: fd=70
D/ViewRootImpl@9596aae[BoticActivity]: setView = DecorView@a27a04f[BoticActivity] touchMode=true
D/ViewRootImpl@9596aae[BoticActivity]: dispatchAttachedToWindow
D/ViewRootImpl@9596aae[BoticActivity]: Relayout returned: oldFrame=[0,0][0,0] newFrame=[0,0][1080,1920] result=0x27 surface={isValid=true -572297216} surfaceGenerationChanged=true
D/ViewRootImpl@9596aae[BoticActivity]: mHardwareRenderer.initialize() mSurface={isValid=true -572297216} hwInitialized=true
D/libEGL: loaded /vendor/lib/egl/libGLES_mali.so
W/art: Before Android 4.1, method int androidx.appcompat.widget.DropDownListView.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView
D/ViewRootImpl@9596aae[BoticActivity]: MSG_RESIZED_REPORT: frame=Rect(0, 0 - 1080, 1920) ci=Rect(0, 72 - 0, 0) vi=Rect(0, 72 - 0, 846) or=1
    MSG_WINDOW_FOCUS_CHANGED 1
    mHardwareRenderer.initializeIfNeeded()#2 mSurface={isValid=true -572297216}
V/InputMethodManager: Starting input: tba=android.view.inputmethod.EditorInfo@3327c99 nm : com.example.myapplicationh81first ic=null
I/InputMethodManager: [IMM] startInputInner - mService.startInputOrWindowGainedFocus
D/InputTransport: Input channel constructed: fd=75
I/OpenGLRenderer: Initialized EGL, version 1.4
D/OpenGLRenderer: Swap behavior 1
D/mali_winsys: EGLint new_window_surface(egl_winsys_display*, void*, EGLSurface, EGLConfig, egl_winsys_surface**, egl_color_buffer_format*, EGLBoolean) returns 0x3000,  [1080x1920]-format:1
V/InputMethodManager: Starting input: tba=android.view.inputmethod.EditorInfo@5cbdb5e nm : com.example.myapplicationh81first ic=null
D/ViewRootImpl@9596aae[BoticActivity]: MSG_RESIZED_REPORT: frame=Rect(0, 0 - 1080, 1920) ci=Rect(0, 72 - 0, 0) vi=Rect(0, 72 - 0, 0) or=1
D/ViewRootImpl@9596aae[BoticActivity]: MSG_WINDOW_FOCUS_CHANGED 0
D/ViewRootImpl@9596aae[BoticActivity]: mHardwareRenderer.destroy()#1
D/ViewRootImpl@9596aae[BoticActivity]: Relayout returned: oldFrame=[0,0][1080,1920] newFrame=[0,0][1080,1920] result=0x5 surface={isValid=false 0} surfaceGenerationChanged=true
D/InputTransport: Input channel destroyed: fd=75

Please use simple words because I don't speak good English.

Answer 1

Add

android:background="#000"

to your LinearLayout or RelativeLayout.

The colors you can choose from this link https://uicolorpicker.com/