/**
  * 字符串顯示到textView, textView maxLines=2
  * 如果字符串太長顯示不下，則用省略號代替
  * 省略號的位置在第一行末尾
  *
  * @param textView 顯示字符串的view
  * @param str  要顯示的字符串
  * @param width 顯示字符串的view的寬
  * @return 處理后帶省略號的字符串
  */
 private String ellipsizeString(TextView textView, String str, int width) {
  Paint paint = textView.getPaint();
  //文字總寬小于2倍的view寬，說明小于2行，直接返回
  if (paint.measureText(str) < 2 * width) {
   return str;
  }

  //存儲顯示到view的每行文字
  List<String> list = new ArrayList<>();

  int len = 0;
  int start, end = 0;

  while (len < str.length()) {
   len += end;
   int count = paint.breakText(str, end, str.length(), true, width, null);
   start = end;
   end = end + count;
   list.add(str.substring(start, end));
  }

  //第一行文字末尾三個字符替換成省略號
  String line1 = list.get(0);
  line1 = line1.substring(0, line1.length() - 3) + "...";

  //最后一行半的文字從末尾向前截取一行文字
  String endLine = list.get(list.size() - 1);
  int endLineWidth = (int) paint.measureText(endLine);
  String minorEndLine = list.get(list.size() - 2);
  int minorCuteCount = paint.breakText(minorEndLine, 0, minorEndLine.length(), true, endLineWidth, null);
  String line2 = minorEndLine.substring(minorCuteCount, minorEndLine.length()) + endLine;

  return line1 + line2;
 }

paint.measureText(str) //測量字符串的寬度 
paint.breakText(str, end, str.length(), true, width, null); //計算指定寬度下顯示的字符串數量