talkback isn't reading alert dialog content

[João de Sousa e Silva]

Dear all,

I am trying to write an application that should have some alert dialogs.
Unfortunatly talkback is not reading the content text of the alert box
of my sample code.

Here it is the code:

AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage("talkback test").setPositiveButton("OK", new
DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.cancel();}
}).show();

This code is placed on the onCreate method of the starting activity.

What am I doing wrong? May you help me?

Many thanks.