android字符串处理(Mms模块短信内容解析)

/***
     *
         * 此方法描述的是：   开始转换了哦
         * @author:[e-mail],[e-mail]
         * @version: 2010-5-13 下午03:32:52
     */
    private CharSequence formatMessage(String contact, String body, String subject,
                                       String timestamp, String highlight) {
        CharSequence template = mContext.getResources().getText(R.string.name_colon); //遇到鬼了     &lt;主题：<xliff:g id="SUBJECT">%s</xliff:g>&gt;"
        SpannableStringBuilder buf =                   //把他当作StringBuffer只是它可以放的不是 String 而已他能放跟多类型的东西
            new SpannableStringBuilder(TextUtils.replace(template,
                new String[] { "%s" },
                new CharSequence[] { contact })); //替换成联系人
        boolean hasSubject = !TextUtils.isEmpty(subject); //主题
        if (hasSubject) {
            buf.append(mContext.getResources().getString(R.string.inline_subject, subject)); //buff先在是 联系人 主题 XXXX      eg wuyi <主题:dsadasdsa> 我爱我家
        }
        if (!TextUtils.isEmpty(body)) {
            if (hasSubject) {
                buf.append(" - "); //如果内容有主题有就+ " - "    eg wuyi <主题:sdsadsadsa> -
            }
            SmileyParser parser = SmileyParser.getInstance(); //获得表情类了哦
            buf.append(parser.addSmileySpans(body)); //追查 急切关注中
        }
        if (!TextUtils.isEmpty(timestamp)) {
            buf.append("\n");
            int startOffset = buf.length();
            // put a one pixel high spacer line between the message and the time stamp as requested
            // by the spec.
            //把之间的信息和时间戳的要求间隔一个像素的高线
            //由规范
            buf.append("\n");
            buf.setSpan(new AbsoluteSizeSpan(3), startOffset, buf.length(),
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            startOffset = buf.length();
            buf.append(timestamp);
            buf.setSpan(new AbsoluteSizeSpan(12), startOffset, buf.length(),
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            // Make the timestamp text not as dark 改变某区域颜色   时间的地方为特殊颜色
            int color = mContext.getResources().getColor(R.color.timestamp_color);
            buf.setSpan(new ForegroundColorSpan(color), startOffset, buf.length(),
                    Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
        if (highlight != null) {
            int highlightLen = highlight.length();
            String s = buf.toString().toLowerCase();
            int prev = 0;
            while (true) {
                int index = s.indexOf(highlight, prev);
                if (index == -1) {
                    break;
                }
                buf.setSpan(new StyleSpan(Typeface.BOLD), index, index + highlightLen, 0);
                prev = index + highlightLen;
            }
        }
        return buf;
    }


**
     * Adds ImageSpans to a CharSequence that replace textual emoticons such
     * as :-) with a graphical version.
     *
     * @param text A CharSequence possibly containing emoticons
     * @return A CharSequence annotated with ImageSpans covering any
     *         recognized emoticons.
     * 添加ImageSpans一个CharSequence的表情符号代替文字等     *如用图形版本:-)。
     * 核心是把表情字符替换成ImageSpans的对象
     */
    public CharSequence addSmileySpans(CharSequence text) {
        SpannableStringBuilder builder = new SpannableStringBuilder(text);
        Matcher matcher = mPattern.matcher(text);
        while (matcher.find()) {
            int resId = mSmileyToRes.get(matcher.group());
            //注意下面的一块有点不好理解哦但是是核心
            builder.setSpan(new ImageSpan(mContext, resId), matcher.start(), matcher.end(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
        return builder;
    }
总结：
     android 在将字符转化为表情图像其核心代码为
builder.setSpan(new ImageSpan(mContext, resId), matcher.start(), matcher.end(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
原理过程是先匹配到表情字符然后通过new ImageSpan(上下文,表情地址)绘制出一个ImageView然后替换掉表情字符。
五、 Android TextView 支持的HTML标签
<a href="...">
<b>
<big>
<blockquote>
<br>
<cite>
<dfn>
<div align="...">
<em>
<font size="..." color="..." face="...">
<h1>
<h2>
<h3>
<h4>
<h5>
<h6>
<i>
<img src="...">
<p>
<small>
<strike>
<strong>
<sub>
<sup>
<tt>