title: CardView not showing shadow elevation
body: <p>I am working with cardviews but the problem is my CardView is not showing any elevation or shadow. I have already tried some of the methods suggested in stackoverflow answers like I have tried using elevation and shadow property. I have also tried using card_view:cardUseCompatPadding="true", but without any success. This is my xml file</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;android.support.v7.widget.CardView
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      xmlns:card_view="http://schemas.android.com/tools"
      android:layout_marginLeft="12dp"
      android:layout_marginRight="12dp"
      android:layout_marginTop="6dp"
      android:layout_marginBottom="6dp"
      app:cardBackgroundColor="#FAFBFD"
      app:cardElevation="5dp"&gt;
  
      &lt;LinearLayout
          android:layout_width="match_parent"
          android:layout_height="wrap_content"
          android:orientation="vertical"&gt;
  
          &lt;RelativeLayout
              android:layout_width="match_parent"
              android:layout_height="wrap_content"&gt;
  
              &lt;de.hdodenhof.circleimageview.CircleImageView
                  android:id="@+id/post_profile_image"
                  android:layout_width="50dp"
                  android:layout_height="50dp"
                  android:src="@mipmap/ic_launcher"
                  android:layout_marginLeft="12dp"
                  android:layout_marginTop="12dp"/&gt;
  
              &lt;LinearLayout
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_toRightOf="@id/post_profile_image"
                  android:layout_marginLeft="12dp"
                  android:orientation="vertical"
                  android:layout_marginTop="16dp"&gt;
  
                  &lt;TextView
                      android:id="@+id/post_username"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:text="Name"
                      android:textAppearance="?android:attr/textAppearanceMedium"
                      android:textColor="#000000"/&gt;
  
                  &lt;TextView
                      android:id="@+id/post_time"
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:layout_marginTop="2dp"
                      android:text="Time"
                      android:textAppearance="?android:attr/textAppearanceSmall"
                      android:textColor="@color/grayColor"/&gt;
              &lt;/LinearLayout&gt;
  
              &lt;LinearLayout
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_alignParentRight="true"&gt;
  
                  &lt;ImageButton
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:background="@android:drawable/ic_delete"
                      android:id="@+id/post_delete_btn"
                      android:visibility="invisible"/&gt;
  
              &lt;/LinearLayout&gt;
  
          &lt;/RelativeLayout&gt;
  
          &lt;ImageView
              android:id="@+id/post_image"
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_centerHorizontal="true"
              android:layout_marginTop="12dp"
              android:adjustViewBounds="true"
              android:background="#00ffffff"
              android:src="@drawable/add_btn"
              android:visibility="gone"/&gt;
  
          &lt;TextView
              android:id="@+id/post_text"
              android:layout_width="wrap_content"
              android:layout_height="wrap_content"
              android:layout_marginTop="12dp"
              android:layout_marginLeft="12dp"
              android:text="Text about Posting...."
              android:textAppearance="?android:attr/textAppearanceMedium"/&gt;
  
          &lt;LinearLayout
              android:layout_width="match_parent"
              android:layout_height="wrap_content"
              android:layout_marginTop="12dp"
              android:layout_marginBottom="8dp"&gt;
  
              &lt;ImageButton
                  android:id="@+id/like_btn"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="12dp"
                  android:background="#00ffffff"
                  android:src="@drawable/grey_like_bt"/&gt;
  
              &lt;TextView
                  android:id="@+id/post_like_count"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="4dp"
                  android:layout_marginTop="8dp"
                  android:text="0 Likes"
                  android:textColor="#2196F3"/&gt;
  
              &lt;ImageButton
                  android:id="@+id/comment_btn"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="32dp"
                  android:background="#00ffffff"
                  android:src="@drawable/comment_btn_gray"/&gt;
  
              &lt;TextView
                  android:id="@+id/post_comment_count"
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"
                  android:layout_marginLeft="4dp"
                  android:layout_marginTop="8dp"
                  android:text="0 Comments"
                  android:textColor="#2196F3"/&gt;
  
              &lt;RelativeLayout
                  android:layout_width="wrap_content"
                  android:layout_height="wrap_content"&gt;
  
                  &lt;ImageButton
                      android:layout_width="wrap_content"
                      android:layout_height="wrap_content"
                      android:background="@android:drawable/ic_menu_edit"
                      android:visibility="invisible"
                      android:id="@+id/post_edit_btn"
                      android:layout_alignParentRight="true"/&gt;
  
              &lt;/RelativeLayout&gt;
  
          &lt;/LinearLayout&gt;
  
      &lt;/LinearLayout&gt;
  
  &lt;/android.support.v7.widget.CardView&gt;
  </code></pre>
  
  <p>Dont know why it is not showing any elevation and shadow</p>