Adding buttons on xml file other than main

I have two xml files in my applic开发者_如何学Goation - main.xml and options.xml.

In both of them I use buttons. The problem is, that while interacting with the buttons in main.xml, I cannot do that with options.xml: if I write

Button b = (Button)findViewById(R.id.b1);

, b is going to be null. What is the cause of this problem and how do I fix it?

Thank you in advance.

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You need to either inflate the options.xml or set it as content view:

setContentView(R.layout.options);

before you can use the views in that layout file.

It sounds like you want to be able to access both layouts so you should do something like this:

View view = LayoutInflater.from(context).inflate(R.layout.options, null);
Button b = (Button) view.findViewById(R.id.b1);