android-Going to next line : I am using LinearyLayout as you see and my problem is why cant i see the imageview at the firstline and the button at the secondline?

    `<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:id="@+id/mainlayout"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
       <LinearLayout
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:orientation="horizontal">
           <ImageView
               android:id="@+id/imageview"
               android:layout_width="match_parent"
               android:layout_height="wrap_content"/>
       </LinearLayout>
    
        <LinearLayout
               android:layout_width="match_parent"
               android:layout_height="wrap_content"
               android:orientation="horizontal">
               <Button
                   android:id="@+id/button"
                   android:layout_width="match_parent"
                   android:layout_height="wrap_content"/>
           </LinearLayout>
        </LinearLayout>
    
    
    
    `