Android Custom Dialog Corner Radius

I am inflating a custom dialog in my android app. The layout of the dialog is this:

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/parent"
    app:cardBackgroundColor="@android:color/white"
    app:cardCornerRadius="15dp"
    app:cardElevation="3dp">
    
    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"
        android:id="@+id/interior_layout"
        android:orientation="vertical">
        
        <ImageView
            android:layout_width="80dp"
            android:layout_height="80dp"
            android:scaleType="centerCrop"
            android:adjustViewBounds="true"
            android:layout_gravity="center_horizontal"
            android:visibility="gone"
            android:id="@+id/imageView"/>
        
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:id="@+id/message"
            android:textSize="14sp"
            android:textColor="@android:color/black"
            android:visibility="gone"
            android:layout_marginTop="10dp"
            android:text="Hello"
            android:layout_gravity="center_horizontal"/>
        
    </LinearLayout>

</androidx.cardview.widget.CardView>

This is my code to inflate the dialog:

        Dialog alertDialog  = new Dialog(activity);
        alertDialog.requestWindowFeature(Window.FEATURE_NO_TITLE);
        dialogView = LayoutInflater.from(activity).inflate(R.layout.layout_progress_dialog, null);
        alertDialog.setContentView(dialogView);
        Objects.requireNonNull(alertDialog.getWindow()).setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));

However, the corner radius is not being set. The corners are still sharp. I tried using Alert Dialog but there I faced the problem that it covers the entire width (just like Progress Dialog). With Dialog, I can have the width as much as needed.

You don't need a CardView to obtain the corner radius.

Just use the getTheme method:

class RoundedDialog: DialogFragment() {

    override fun getTheme() = R.style.RoundedCornersDialog
    
    override fun onCreateView(...): View? {
       val v: View = inflater.inflate(R.layout...., container, false)
       return v
    }

    //...
}

with:

<style name="RoundedCornersDialog" parent="@style/Theme.MaterialComponents.Dialog">
        <item name="dialogCornerRadius">16dp</item>
</style>

If you want to use a AlertDialog you can create it in the onCreateDialog. Check this answer for more details.

You can go for creating a drawable and then making it the background of the view.

You can use the following piece of code to make round corners- just create a new drawable and

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android" >
    <stroke
        android:width="1dp"
        android:color="@color/colorPrimaryDark" />
    <solid android:color="#2ED771" />
    <padding
        android:left="1dp"
        android:right="1dp"/>
    <corners android:radius="15dp" />
</shape>

WIth this you can also specify radius of each corner independently