mTextSize这个变量，在整个过程中都没有使用啊

<co.customview.RoundProgressBar
   android:visibility="visible"
   android:id="@+id/progressbar"
   android:background="@color/black5"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_centerInParent="true"
   custom:progress_radius="30dp"
   custom:progress_text_size="12dp"
   custom:progress_text_color="@color/white_bg"
   custom:progress_reach_color="@color/colorAccent"
   custom:progress_unReach_color="@color/white_bg"/>