Question

I have a block of Views containing an ImageView, a Button and a TextView. I want to create this block dynamically in the Java code. Is there a way to define this block in XML, alter the src/text attributes and append it to my current layout?

Thanks!

Ron

Answer 1

I use the following technique:

<!-- content.xml -->
<merge>
  <ImageView android:id="@+id/image />
  <Button android:id="@+id/button />
  <TextView android:id="@+id/text />
</merge>

Then inflate using a LayoutInflater:

View block = inflater.inflate(R.layout.content, root, attach);
(TextView) textView = (TextView) block.findViewById(R.id.text);
textView.setText(text);

I found this especially useful when you write a custom View extending a ViewGroup (eg LinearLayout or RelativeLayout) and you want to define the content in a declarative XML. For example

public class MyWidget extends LinearLayout {

  // Invoked by all of the constructors
  private void setup() {
    Context ctx = getContext();
    inflate(ctx, R.layout.content, this);
    ((TextView) findViewById(R.id.text)).setText(
        ctx.getString(R.string.hello_world)
    );
  }
}

A possible variation is using a Layout instead of <merge> if you don’t need it. The LayoutInflater can be obtained by Activity.getLayoutInflater() or by any Context via getSystemService() (you have to cast the result to a LayoutInflater object in the latter case.