Android中ActionBar正中

经常会用到将ActionBar文字居中的问题，这里写个代码如下：

    //把actionBar的文字标题居中    public static void centerActionBarTitle(Activity activity)    {        int titleId = activity.getResources().getIdentifier("action_bar_title", "id", "android");        if (titleId<=0)return;        TextView titleTextView = (TextView)activity.findViewById(titleId);        DisplayMetrics metrics = activity.getResources().getDisplayMetrics();        LinearLayout.LayoutParams txvPars = (LinearLayout.LayoutParams) titleTextView.getLayoutParams();        txvPars.gravity = Gravity.CENTER_HORIZONTAL;        txvPars.width = metrics.widthPixels;        titleTextView.setLayoutParams(txvPars);        titleTextView.setGravity(Gravity.CENTER);}