用CardView实现图片圆角

<android.support.v7.widget.CardView
        android:layout_width = "100dp"
        android:layout_height = "100dp"
        app:cardCornerRadius="5dp"
        app:cardElevation="0dp"
        android:layout_alignTop="@id/tv_clinic_direction"
        android:layout_marginRight="35dp"
        android:layout_alignParentRight="true"
        >
        <ImageView
            android:id="@+id/iv_clinic_avatar"
            android:layout_width = "100dp"
            android:layout_height = "100dp"
            android:background="@drawable/bg_clinic_image"
            android:src="@mipmap/img_zszp"
            android:scaleType="centerCrop"
            />
    </android.support.v7.widget.CardView>