Can I implement some logic in XML?

开发者_StackOverflow社区I need XML for creating layouts in my Android apps and what I wanted to know is the following. Can I implement some logic in XML? For instance, I wanted to position my text exactly "(fill_parent - (the width of the image))/2"... something like this.

you cant do that directly in xml file. if u want to position ur text exactly means just set the positons of the text, check properities of text.

  setContentView(R.layout.main);

    tv=(TextView) findViewById(R.id.textView1);

• main.xml

  contains textview with id textview1. like this u can acess the textview of ur xml file..

Not inside the XML. The usual way this is done is to locate the views with findViewById() in onCreate() after the setContentView(), then adjust the relevant properties programmatically.

Edit: after re-reading the example in the question, my advice seems too general (towards modifying any properties on a view). For calculated layout positions you are better achieving these kinds of results with relative layouts or some of the specialized view containers.