CardView not showing shadow elevation

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 ``` <?xml version="1.0" encoding="utf-8"?> <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"> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:orientation="vertical"> <RelativeLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <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"/> <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"> <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"/> <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"/> </LinearLayout> <LinearLayout android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_alignParentRight="true"> <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"/> </LinearLayout> </RelativeLayout> <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"/> <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"/> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="12dp" android:layout_marginBottom="8dp"> <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"/> <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"/> <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"/> <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"/> <RelativeLayout android:layout_width="wrap_content" android:layout_height="wrap_content"> <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"/> </RelativeLayout> </LinearLayout> </LinearLayout> </android.support.v7.widget.CardView> ``` Dont know why it is not showing any elevation and shadow