[android] Android simple alert dialog

I need to show a little text message to the users that clicks a button on my Android app, on IOS I just had to create an AlertView that it's simple to use but with Android i'm struggling because the solution seems x10 times harder. I saw that I need to use a DialogFragment but I can't understand how to make it work, can someone explain? Also, is my solution right or there is something easier to show a simple text message to users?

You can easily make your own 'AlertView' and use it everywhere.

alertView("You really want this?");

Implement it once:

private void alertView( String message ) {
 AlertDialog.Builder dialog = new AlertDialog.Builder(context);
 dialog.setTitle( "Hello" )
       .setIcon(R.drawable.ic_launcher)
       .setMessage(message)
//     .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
//      public void onClick(DialogInterface dialoginterface, int i) {
//          dialoginterface.cancel();   
//          }})
      .setPositiveButton("Ok", new DialogInterface.OnClickListener() {
        public void onClick(DialogInterface dialoginterface, int i) {   
        }               
        }).show();
 }

No my friend its very simple, try using this:

AlertDialog alertDialog = new AlertDialog.Builder(AlertDialogActivity.this).create();
alertDialog.setTitle("Alert Dialog");
alertDialog.setMessage("Welcome to dear user.");
alertDialog.setIcon(R.drawable.welcome);

alertDialog.setButton(AlertDialog.BUTTON_POSITIVE, "OK", new DialogInterface.OnClickListener() {
    public void onClick(DialogInterface dialog, int which) {
        Toast.makeText(getApplicationContext(), "You clicked on OK", Toast.LENGTH_SHORT).show();
    }
});

alertDialog.show();

This tutorial shows how you can create custom dialog using xml and then show them as an alert dialog.