android - 将 RecyclerView CardView 背景更改为透明

Question

问题简版:

I want to make my CardView and RecyclerView background transparent, so the fragment/activity background should become visible.

解释:

我有一个带有背景图像的 Activity A 并且 fragment B 在其 Framelayout 上被替换，在 fragment B 我有 recyclerView 和 CardView 现在的问题是我想让每个背景透明 所以只有 CardView 在 Activity 的实际背景下可见

RecyclerView 看起来像这样(这些白色背景应该是透明的):

代码

Activity (A)

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
        android:id="@+id/fl"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/transparent"
        android:backgroundTint="@android:color/transparent"/>

fragment (B) RecyclerView

<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:backgroundTint="@android:color/transparent"
    android:background="@android:color/transparent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rv"
        tools:listitem="@layout/layout_video_item"
        android:backgroundTint="@android:color/transparent"
        android:background="@android:color/transparent"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <TextView
        android:id="@+id/tv_not_found"
        android:text="No Media Found Yet"
        android:layout_gravity="center"
        android:gravity="center"
        android:visibility="gone"
        android:textAppearance="@style/TextAppearance.AppCompat.Large"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</android.support.design.widget.CoordinatorLayout>

CardView/项目布局

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginEnd="3dp"
    android:layout_marginStart="3dp"
    android:layout_marginTop="3dp"
    android:background="@android:color/transparent">

    <android.support.v7.widget.CardView
        style="@style/CardView.Light"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:cardUseCompatPadding="true"
        android:background="@android:color/transparent"
        android:backgroundTint="@android:color/transparent"
        app:cardCornerRadius="5dp"
        android:padding="0dp"
        app:cardElevation="0dp"
        tools:ignore="ContentDescription">

        <android.support.constraint.ConstraintLayout xmlns:app="http://schemas.android.com/apk/res-auto"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="0dp"
            android:background="@color/colorAccent">

            <ImageView
                android:id="@+id/media_image"
                android:layout_width="100dp"
                android:layout_height="0dp"
                android:scaleType="centerCrop"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toStartOf="parent"
                app:layout_constraintTop_toTopOf="parent"
                app:srcCompat="@android:color/darker_gray" />

            <ImageButton
                android:id="@+id/ib_delete"
                android:layout_width="30dp"
                android:layout_height="40dp"
                android:background="#00FFFFFF"
                android:padding="12dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toEndOf="parent"
                app:srcCompat="@drawable/ic_delete_white_24dp" />

            <ImageButton
                android:id="@+id/share_button"
                android:layout_width="30dp"
                android:layout_height="40dp"
                android:background="#00FFFFFF"
                android:padding="12dp"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintEnd_toStartOf="@+id/ib_delete"
                app:srcCompat="@drawable/ic_share_white_24dp" />

            <TextView
                android:id="@+id/tv_video_name"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginStart="5dp"
                android:ellipsize="marquee"
                android:singleLine="true"
                android:text="Title Test"
                android:textAppearance="@style/TextAppearance.AppCompat.Large.Inverse"
                android:textColor="@color/colorPrimaryText"
                app:layout_constraintEnd_toStartOf="@+id/tv_ribbon"
                app:layout_constraintStart_toEndOf="@+id/media_image"
                app:layout_constraintTop_toTopOf="parent" />

            <TextView
                android:id="@+id/tv_ribbon"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:background="@android:color/holo_red_light"
                android:ellipsize="marquee"
                android:fontFamily="monospace"
                android:padding="3dp"
                android:singleLine="true"
                android:text="New"
                android:textColor="@color/colorIcons"
                android:textSize="14sp"
                android:visibility="gone"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintTop_toTopOf="parent" />

            <TextView
                android:id="@+id/tv_path"
                android:layout_width="0dp"
                android:layout_height="wrap_content"
                android:layout_marginEnd="8dp"
                android:layout_marginStart="5dp"
                android:ellipsize="marquee"
                android:singleLine="true"
                android:text="subtitle test"
                app:layout_constraintEnd_toEndOf="parent"
                app:layout_constraintStart_toEndOf="@+id/media_image"
                app:layout_constraintTop_toBottomOf="@+id/tv_video_name" />

            <ImageView
                android:id="@+id/iv_is_audio"
                android:layout_width="25dp"
                android:layout_height="25dp"
                android:layout_marginBottom="8dp"
                android:layout_marginStart="5dp"
                android:layout_marginTop="8dp"
                android:visibility="invisible"
                app:layout_constraintBottom_toBottomOf="parent"
                app:layout_constraintStart_toEndOf="@+id/media_image"
                app:layout_constraintTop_toBottomOf="@+id/tv_duration"
                app:srcCompat="@drawable/ic_settings_voice_black_24dp" />

            <ImageView
                android:id="@+id/iv_is_video"
                android:layout_width="25dp"
                android:layout_height="25dp"
                android:layout_marginStart="5dp"
                android:visibility="invisible"
                app:layout_constraintBottom_toBottomOf="@+id/iv_is_audio"
                app:layout_constraintStart_toEndOf="@+id/iv_is_audio"
                app:layout_constraintTop_toTopOf="@+id/iv_is_audio"
                app:srcCompat="@drawable/ic_theaters" />

            <ImageView
                android:id="@+id/iv_is_gif"
                android:layout_width="35dp"
                android:layout_height="30dp"
                android:layout_marginStart="5dp"
                android:visibility="invisible"
                app:layout_constraintBottom_toBottomOf="@+id/iv_is_video"
                app:layout_constraintStart_toEndOf="@+id/iv_is_video"
                app:layout_constraintTop_toTopOf="@+id/iv_is_video"
                app:srcCompat="@drawable/ic_gif" />

            <TextView
                android:id="@+id/tv_duration"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="5dp"
                android:layout_marginTop="8dp"
                android:text="0:00"
                app:layout_constraintStart_toEndOf="@+id/media_image"
                app:layout_constraintTop_toBottomOf="@+id/tv_path" />

            <TextView
                android:id="@+id/tv_size"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_marginStart="8dp"
                android:text="0 MB"
                app:layout_constraintBottom_toBottomOf="@+id/tv_duration"
                app:layout_constraintStart_toEndOf="@+id/tv_duration"
                app:layout_constraintTop_toTopOf="@+id/tv_duration" />


        </android.support.constraint.ConstraintLayout>

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

</RelativeLayout>

提问的原因:

我知道有很多 SO 问题可以完成同样的任务，但我的要求略有不同，问这个问题的原因是没有什么对我有用。

期待

Answer 1

将 CardView 背景设置为 app:cardBackgroundColor="#00ffffff"