Android Spinner - How to make dropdown view transparent?

Question

I have a custom spinner dropdown xml file in /res/layout/:

spinner_view_dropdown.xml:

<?xml version="1.0" encoding="UTF-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/spinner_item_dropdown"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="@android:color/transparent"
style="@style/spinner_item_dropdown" />

I'm setting the spinner dropdown via java:

// "Spinner", aka breadcrumbs
 Spinner spin = (Spinner) findViewById(R.id.breadcrumb_dropdown);

 ArrayAdapter adapter = ArrayAdapter.createFromResource(this, R.array.breadcrumb, R.layout.spinner_view);

 adapter.setDropDownViewResource(R.layout.spinner_view_dropdown);

 spin.setAdapter(adapter);
 // /"Spinner"

Unfortunately, a white background still exists on the spinner popup regardless if I set the background to transparent.

How do I fix this?

Answer 1

I suspect you can't. The "drop-down" is a dialog that you are not creating and therefore have no direct control over.

Answer 2

The layout you're defining is only used for an entry of your drop-down, not the drop-down itself. So setting the background to transparent won't have any effect on its background. But even if it would, setting the background to transparent would still have no effect, because a TextView (actually I believe any view) has a transparent background by default.

That being said, the right question would be: can you provide a custom layout for an entry's parent view (which is probably a List)? As far as I know, the answer is no, unfortunately.

Answer 3

Try

android:cacheColorHint="#00000000"

to get transparency.

I dont know if it works for you but there is a post http://android-developers.blogspot.com/2009/01/why-is-my-list-black-android.html that explains why the moving parts of a list appear in the background color.

Maybe its the same issue with your spinner.

Answer 4

It's a bug in 1.5 I think, see here

http://www.symsource.com/index.php?view=article&id=418&option=com_content&format=pdf

Run it in a 1.6 emulator or device, does it still stay white?

I actually came here looking for an approach to this, I suspect this may involve manually writing to the canvas or something like that.

Any ideas.

P.S. Accidentally posted when I thought I was logged in, anyone know how to get rid of the anonymous comment? Maybe an admin could fix this?