android - Fade In Main Activity -

i'm complete newbie android. how can fade in main activity? after open app want screen black , fade in image. have been trying last 2 hours , can't seem find solution.

this code:

package com.example.radu.gladiators2;  import android.os.bundle; import android.support.annotation.nullable; import android.support.v7.app.appcompatactivity; import android.view.view; import android.view.windowmanager; import android.view.animation.animation; import android.view.animation.animationutils; import android.widget.imageview;  /**  * created radu on 8/8/2016. */  public class splash extends appcompatactivity {  @override protected void oncreate(@nullable bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.splash_screen); }  @override public void onwindowfocuschanged(boolean hasfocus) {     super.onwindowfocuschanged(hasfocus);     view decorview = getwindow().getdecorview();     if (hasfocus) {         decorview.setsystemuivisibility(                 view.system_ui_flag_layout_stable                 | view.system_ui_flag_layout_hide_navigation                 | view.system_ui_flag_layout_fullscreen                 | view.system_ui_flag_hide_navigation                 | view.system_ui_flag_fullscreen                 | view.system_ui_flag_immersive_sticky);}     } } 

and xml:

<?xml version="1.0" encoding="utf-8"?> <linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent">  <imageview     android:layout_width="match_parent"     android:layout_height="match_parent"     android:src="@drawable/splash_image"     android:id="@+id/imageview"     android:scaletype="centercrop" /> 

try this:

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"     android:layout_width="match_parent"     android:layout_height="match_parent"     android:layoutanimation="@android.r.anim.fade_in" >  <imageview     android:layout_width="match_parent"     android:layout_height="match_parent"     android:src="@drawable/splash_image"     android:id="@+id/imageview"     android:scaletype="centercrop" />