CardView Corner Radius

Solution 1:

Unless you try to extend the Android CardView class, you cannot customize that attribute from XML.

Nonetheless, there is a way of obtaining that effect.

Place a CardView inside another CardView and apply a transparent background to your outer CardView and remove its corner radius ("cornerRadios = 0dp"). Your inner CardView will have a cornerRadius value of 3dp, for example. Then apply a marginTop to your inner CardView, so its bottom bounds will be cut by the outer CardView. This way, the bottom corner radius of your inner CardView will be hidden.

The XML code is the following:

 <android.support.v7.widget.CardView
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:id="@+id/card_view_outer"
    android:layout_width="match_parent"
    android:layout_height="200dp"
    android:layout_gravity="center"
    card_view:cardBackgroundColor="@android:color/transparent"
    card_view:cardCornerRadius="0dp"
    card_view:cardElevation="3dp" >

    <android.support.v7.widget.CardView
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_view_inner"
        android:layout_width="match_parent"
        android:layout_height="200dp"
        android:layout_gravity="center"
        android:layout_marginTop="3dp"
        card_view:cardBackgroundColor="@color/green"
        card_view:cardCornerRadius="4dp"
        card_view:cardElevation="0dp" >
    </android.support.v7.widget.CardView>
</android.support.v7.widget.CardView>

And the visual effect is the following:

Always put your content in your Inner CardView. Your outer CardView serves only the purpose of "hiding" the bottom Rounded Corners of the inner CardView.

Solution 2:

You can use the standard MaterialCard included in the official Material Components library.

Use in your layout:

<com.google.android.material.card.MaterialCardView
        style="@style/MyCardView"
        ...>

In your style use the shapeAppearanceOverlay attribute to customize the shape (the default corner radius is 4dp)

  <style name="MyCardView" parent="@style/Widget.MaterialComponents.CardView">
    <item name="shapeAppearanceOverlay">@style/ShapeAppearanceOverlay.MaterialCardView.Cut</item>
  </style>


  <style name="ShapeAppearanceOverlay.MaterialCardView.Cut" parent="">
    <item name="cornerFamily">rounded</item>
    <item name="cornerSizeTopRight">8dp</item>
    <item name="cornerSizeTopLeft">8dp</item>
    <item name="cornerSizeBottomRight">0dp</item>
    <item name="cornerSizeBottomLeft">0dp</item>
  </style>

You can also use:

<com.google.android.material.card.MaterialCardView
     app:shapeAppearanceOverlay="@style/ShapeAppearanceOverlay.MaterialCardView.Cut"
     ...>

It is the result:

Solution 3:

dependencies: compile 'com.android.support:cardview-v7:23.1.1'

<android.support.v7.widget.CardView
    android:layout_width="80dp"
    android:layout_height="80dp"
    android:elevation="12dp"
    android:id="@+id/view2"
    app:cardCornerRadius="40dp"
    android:layout_centerHorizontal="true"
    android:innerRadius="0dp"
    android:shape="ring"
    android:thicknessRatio="1.9">
    <ImageView
        android:layout_height="80dp"
        android:layout_width="match_parent"
        android:id="@+id/imageView1"
        android:src="@drawable/Your_image"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true">
    </ImageView>
</android.support.v7.widget.CardView>

Solution 4:

There is an example how to achieve it, when the card is at the very bottom of the screen. If someone has this kind of problem just do something like that:

<android.support.v7.widget.CardView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="-5dp"
    card_view:cardCornerRadius="4dp">

    <SomeView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="5dp">

    </SomeView>

</android.support.v7.widget.CardView>

Card View has a negative bottom margin. The view inside a Card View has the same, but positive bottom margin. This way rounded parts are hidden below the screen, but everything looks exactly the same, because the inner view has a counter margin.

Solution 5:

You can use this drawable xml and set as background to cardview :

<?xml version="1.0" encoding="UTF-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <solid android:color="#ffffffff"/>

    <stroke android:width="1dp"
        android:color="#ff000000"
        />

    <padding android:left="1dp"
        android:top="1dp"
        android:right="1dp"
        android:bottom="1dp"
        />

    <corners 
        android:topLeftRadius="7dp"
        android:topRightRadius="7dp"/>
</shape>