Question

I am from Java Swing background. May I know why using XML to create GUI is a good practice in Android? For instance, instead of writing the code in (Which makes me feel more comfortable with it as I use to Swing desktop application)

import android.app.Activity;
import android.os.Bundle;
import android.widget.TextView;

public class HelloAndroid extends Activity {
   /** Called when the activity is first created. */
   @Override
   public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       TextView tv = new TextView(this);
       tv.setText("Hello, Android");
       setContentView(tv);
   }
}

We write the code in XML way.

import android.app.Activity;
import android.os.Bundle;

public class HelloAndroid extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }
}

In tutorial, it states that,

This structure makes it very easy to
quickly build up UIs, using a more
simple structure and syntax than you
would use in a programmatic layout.

However, I don’t really buy the idea, as I feel that creating a separate XML file is more cumbersome.

Can anyone give a real world example (in the sense of Android), why using XML to build GUI is more superior than bare Java code?

If GUI programming through XML is really a good stuff, why it still hasn’t become a common practice among GUI desktop application developers?

Answer 1

Using XML layouts has many advantages over Java code. You get easy references to strings, drawables, dimensions, themes, etc. But the biggest advantage is automatic support for multiple configurations. Without changing your code you can have different layouts for landscape and portrait by just having an XML layout in layout-land/ and layout-port/. And you can do the same to adapt the layout to different resolutions, languages, etc.