I recently migrated my app to Material Design and I stumbled upon this problem with my Alert Dialogs:
As ironman told me here, be sure that you import the right class.
Right : import android.support.v7.app.AlertDialog;
Wrong : import android.app.AlertDialog;
Use the theme in parent
AlertDialog.THEME_DEVICE_DEFAULT_LIGHT
I had the exact same symptom but for me it was actually that I had used the standard frameworks AlertDialog (and its Builder) instead of android.support.v7.app.AlertDialog, switching to use the one from the support library fixed the issue for me.
The point is here:
<style name="Theme.AlertDialog" parent="Base.V14.Theme.AppCompat.Dialog">
...
<item name="colorPrimary">@color/theme_primary</item>
<item name="colorPrimaryDark">@color/theme_primary_dark</item>
<item name="colorAccent">@color/theme_accent_dark</item>
...
<item name="android:windowBackground">@android:color/transparent</item>
...
</style>
Add below styles . You have to customise background also.
<item name="android:windowFrame">@null</item>
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:windowIsFloating">true</item>
<item name="android:windowContentOverlay">@null</item>
<item name="android:windowTitleStyle">@null</item>
<item name="android:windowAnimationStyle">@android:style/Animation.Dialog</item>
<item name="android:backgroundDimEnabled">false</item>
<item name="android:background">@android:color/transparent</item>
Using below also works
<item name="android:windowBackground">@android:color/transparent</item>
<item name="android:background">@android:color/transparent</item>
Also You can set in your code by using
dialog.getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));
and this should be before setContentView
dialog.setContentView(R.layout.dialog);