android - 仅将 alpha-transparency 设置为布局而不是其子级

Question

这个问题在这里已经有了答案:

Android: Nested linear layout with different alpha value (5 个回答)

关闭 9年前。

我发现了这个问题，我也遇到了几乎同样的问题。我如何将 alpha 仅应用于相对布局而不应用于其子布局？有人可以帮忙吗？

I have a rectangular LinearLayout that has some margin, some round corners and an alpha value of 0.3. Inside this layout I have 4 different layouts as I display different images in different positions. My issue is that although the primary layout is 0.3, I want my child to be fully visible, or not affected by it's parent alpha, and I am wondering how I can please do that please? I have tried setting alpha=1 on the children layouts but it did not work. Setting it to 0 does make the children layout disappear though, so it seems I can reduce below 0.3 but not anything above the parent. Is that a bug or am I doing it wrong please? Thank you.

Answer 1

您可以使用 FrameLayout 代替设置父级的 alpha 并首先设置背景图像并设置该子级的 alpha。例如

而不是使用这个

<LinearLayout 
        android:background="@drawable/background" 
        android:alpha="0.3" >
    <LinearLayout>
        <Button />
        <Button />
    </LinearLayout>     
</LinearLayout >

用这个

<FrameLayout>
    <ImageView
        android:background="@drawable/background" 
        android:alpha="0.3" />
    <LinearLayout>
        <Button />
        <Button />
    </LinearLayout>     
</FrameLayout>