addContentViewの使い方

@Override  
    protected void onCreate(Bundle savedInstanceState) {   
        // TODO Auto-generated method stub   
        super.onCreate(savedInstanceState);   
  
        TextView tv = new TextView(this);   
        FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(   
        FrameLayout.LayoutParams.WRAP_CONTENT,   
        FrameLayout.LayoutParams.WRAP_CONTENT);   
        //          (     )   
        params.topMargin = 0;   
        params.gravity = Gravity.TOP | Gravity.CENTER_HORIZONTAL;   
  
        tv.setText("    ...dynamic layout");   
        addContentView(tv, params);   
        // setContentView(tv);   
    }