Dialog with transparent background in Android

Question

How do I remove the black background from a dialog box in Android. The pic shows the problem.

Answer 1

One issue I found with all the existing answers is that the margins aren't preserved. This is because they all override the android:windowBackground attribute, which is responsible for margins, with a solid color. However, I did some digging in the Android SDK and found the default window background drawable, and modified it a bit to allow transparent dialogs.

First, copy /platforms/android-22/data/res/drawable/dialog_background_material.xml to your project. Or, just copy these lines into a new file:

Notice that android:color is set to ?attr/colorBackground. This is the default solid grey/white you see. To allow the color defined in android:background in your custom style to be transparent and show the transparency, all we have to do is change ?attr/colorBackground to @android:color/transparent. Now it will look like this:

After that, go to your theme and add this:

Make sure to replace newly_created_background_name with the actual name of the drawable file you just created, and replace some_transparent_color with the desired transparent background.

After that all we need to do is set the theme. Use this when creating the AlertDialog.Builder:

    AlertDialog.Builder builder = new AlertDialog.Builder(this, R.style.MyTransparentDialog);

Then just build, create, and show the dialog as usual!