Android: How to keep corner radius while setting a background drawable?

问题

<android.support.v7.widget.CardView 
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:card_view="http://schemas.android.com/apk/res-auto"
  android:id="@+id/card_view"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:layout_margin="@dimen/activity_vertical_margin"
  card_view:cardCornerRadius="12dp"
  card_view:cardElevation="12dp">

    <LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">

    .....

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

This is what I set in layout.xml

I'd like to programmatically change the background of the card at runtime.

CardView card =(CardView) findViewById(R.id.card_view);
card.setBackgroundResource(R.drawable.card1);

This will set all radius corners to 0dp. I'd like to keep the radius and the background drawable.

回答1:

Use card_view:cardBackgroundColor="#FFFFFFFF" instead of android:background="#FFFFFFFF"
Programatically use, card.setCardBackgroundColor(color) instead of card.setBackgroundColor(color)

回答2:

Instead of CardView you can set background resource for layout containing by that cardview like following.

<android.support.v7.widget.CardView 
  xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:card_view="http://schemas.android.com/apk/res-auto"
  android:id="@+id/card_view"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:layout_margin="@dimen/activity_vertical_margin"
  card_view:cardCornerRadius="12dp"
  card_view:cardElevation="12dp">

    <LinearLayout
        android:id="@+id/myLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            .....
    </LinearLayout>

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

and

LinearLayout myLayout=(LinearLayout) findViewById(R.id.myLayout);
myLayout.setBackgroundResource(R.drawable.card1);

I hope this will help you.

来源：https://stackoverflow.com/questions/31558251/android-how-to-keep-corner-radius-while-setting-a-background-drawable