跨度文本的所有其他条件是什么

Question

我正在尝试使用所有的span条件（如果没有）进行文本样式设置，但是由于spanStart在0等之前开始时，我总是会遇到错误。任何人都可以为我提供哪些条件，我应该检查哪些条件才能为我的编辑文本赋予样式。这是我的代码

Spannable str = texto.getText();
  int selStart = texto.getSelectionStart();
  int selEnd = texto.getSelectionEnd();
  StyleSpan[] styleSpans = texto.getText().getSpans(selStart, selEnd, StyleSpan.class);

  for (StyleSpan styleSpan : styleSpans) {

      int oldStyle = styleSpan.getStyle();
      int spanStart = str.getSpanStart(styleSpan);
      int spanEnd = str.getSpanEnd(styleSpan);

      if (spanStart < texto.getSelectionStart()) {
          str.setSpan(new StyleSpan(oldStyle), spanStart, selStart, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
      }

      if (spanEnd > texto.getSelectionEnd()) {
          str.setSpan(new StyleSpan(oldStyle), selEnd, spanEnd, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
      }
      if (selEnd > selStart) {
          if (oldStyle == Typeface.ITALIC) {
              str.removeSpan(styleSpan);
              italicExists = true;
          }
          if (oldStyle == Typeface.BOLD_ITALIC) {
              str.setSpan(new StyleSpan(Typeface.BOLD), spanStart, spanEnd, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
              italicExists = false;
          }
      }