What is it? in Android XML means

Question

Possible duplicate:
Question mark (?) In XML attributes for Android

<TextView android:id="@+android:id/title" android:layout_width="wrap_content" android:layout_height="wrap_content" android:singleLine="true" android:textAppearance="?android:attr/textAppearanceLarge" android:ellipsize="marquee" android:fadingEdge="horizontal" /> 

what is he doing?? android: attr / textAppearanceLarge? Does he have a name? Why doesn't he use "@" instead? Can I use this syntax in my own code? Where can I find out more about this? Since I do not know what it is, it is difficult to find additional information about it. Any guidance would be greatly appreciated.

Answer 1

This question has already been asked in stackoverflow. The answer was as follows:

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Answer 2

This is a reference to a style attribute. Check out this link:

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