//not work

textView.setTypeface(Typeface.defaultFromStyle(Typeface.BOLD));

    //work!

    static public void setTextBold(TextView textView, boolean isBold) {

        try {

            if(textView != null) {

                Paint paint = textView.getPaint();

                if(paint != null) {

                    paint.setFakeBoldText(isBold);

                }

            }

        } catch (Throwable var3) {

        }

    }