Android: How to create a Dialog without a title?

Question

I'm trying to generate a custom dialog in Android. I create my Dialog like this:

dialog = new Dialog(this);
dialog.setContentView(R.layout.my_dialog);

Everythings works fine except for the title of the Dialog. Even if I don't set the title of the dialog the dialog popup has a blank space at the position of the dialog.

Is there any way to hide this part of the Dialog?

I tried it with an AlertDialog but it seems the layout is not set properly:

LayoutInflater inflater = 
    (LayoutInflater) this.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View view = inflater.inflate(R.layout.map_dialog, null);

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setView(view);

// dialog = new Dialog(this);
// dialog.setContentView(R.layout.map_dialog);

dialog = builder.create();

((TextView) dialog.findViewById(R.id.nr)).setText(number);

If I use this code I get a null Pointer Exception in the last line. The dialog is not null so the TextView I try to retrieve does not exist.
If I uncomment the part where I use the Dialog Constructor everything works fine but for the title above my dialog layout.

Answer 1

FEATURE_NO_TITLE works when creating a dialog from scratch, as in:

Dialog dialog = new Dialog(context);
dialog.requestWindowFeature(Window.FEATURE_NO_TITLE);

But it doesn't work when creating an AlertDialog (or using the Builder), because it already disables the title and use a custom one internally.

I have looked at the SDK sources, and I think that it can't be worked around. So to remove the top spacing, the only solution is to create a custom dialog from scratch IMO, by using the Dialog class directly.

Also, one can do that with a style, eg in styles.xml:

<style name="FullHeightDialog" parent="android:style/Theme.Dialog">
   <item name="android:windowNoTitle">true</item>
</style>

And then:

Dialog dialog = new Dialog(context, R.style.FullHeightDialog);