本工具类功能：

给TextView设置部分大小
给TextView设置部分颜色
给TextView设置下划线
半角转换为全角
去除特殊字符或将所有中文标号替换为英文标号

/**
 * Created by peng on 2015/06/16.
 * 文本框工具类
 */
public class TextViewUtil {

    //给TextView设置部分大小
    public static void setPartialSize(TextView tv, int start, int end, int textSize) {
        String s = tv.getText().toString();
        Spannable spannable = new SpannableString(s);
        spannable.setSpan(new AbsoluteSizeSpan(textSize), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        tv.setText(spannable);
    }

    //给TextView设置部分颜色
    public static void setPartialColor(TextView tv, int start, int end, int textColor) {
        String s = tv.getText().toString();
        Spannable spannable = new SpannableString(s);
        spannable.setSpan(new ForegroundColorSpan(textColor), start, end, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        tv.setText(spannable);
    }

    //给TextView设置下划线
    public static void setUnderLine(TextView tv) {
        if (tv.getText() != null) {
            String udata = tv.getText().toString();
            SpannableString content = new SpannableString(udata);
            content.setSpan(new UnderlineSpan(), 0, udata.length(), 0);
            tv.setText(content);
            content.setSpan(new UnderlineSpan(), 0, udata.length(), 0);
        } else {
            tv.getPaint().setFlags(Paint.UNDERLINE_TEXT_FLAG);
        }
    }

    //取消TextView的置下划线
    public static void clearUnderLine(TextView tv) {
        tv.getPaint().setFlags(0);
    }

    //半角转换为全角
    public static String ToDBC(String input) {
        char[] c = input.toCharArray();
        for (int i = 0; i < c.length; i++) {
            if (c[i] == 12288) {
                c[i] = (char) 32;
                continue;
            }
            if (c[i] > 65280 && c[i] < 65375)
                c[i] = (char) (c[i] - 65248);
        }
        return new String(c);
    }

    //去除特殊字符或将所有中文标号替换为英文标号
    public static String replaceCharacter(String str) {
        str = str.replaceAll("【", "[").replaceAll("】", "]")
                .replaceAll("！", "!").replaceAll("：", ":").replaceAll("（", "(").replaceAll("（", ")");// 替换中文标号
        String regEx = "[『』]"; // 清除掉特殊字符
        Pattern p = Pattern.compile(regEx);
        Matcher m = p.matcher(str);
        return m.replaceAll("").trim();
    }

}