Question

Contiuned from : This is my question

So now i can use this code :

Window a = getWindow();
    a.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

Instead of this code :

getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);

And some of my Senior’s said that because of getWindow(); method is returning a Window Object we can use both of the code above.
My question is : why we need to get a returned Window object from this code : Window a = getWindow();

I think when i do this i already have a Window Object

Window a;

But why is it not working?

And my 2nd question is why can’t i do like this :

Window a = new Window();

I think it’s create a Window object too.

Why must I use the getWindow(); method?

Thanks all

PS: English is not my native language, so sorry if I made some mistakes

Answer 1

I’m assuming java here:

Window a;

does not create a new Window object, it only creates a variable, which can hold an object of type Window. To create the object itself – you need to invoke its constructor, in your case – I assume that what getWindow() does.

Also, new Window is a syntax error – constructors in java are invoked similar to methods [with () and relevant arguments, if there are any].