本文转载：http://blog.csdn.net/cjh200102/article/details/6824895
//2、提取html的正文 类using
System; using
System.Text; namespace
HtmlStrip { class
MainClass { public
static
void
Main (string[] args) { string
str = "<div>abc</div><span>efg</span><br /><script>888</script><!--<PA>WW</PA-->oo"; //System.IO.StreamReader rd=new System.IO.StreamReader ("/home/lx/test.html"); //str=rd.ReadToEnd (); HtmlParser t = new
HtmlParser (str); // t.KeepTag (new
string[] { "br"
}); //设置br标签不过虑 Console.Write (t.Text ()); } } class
HtmlParser { private
string[] htmlcode; //把html转为数组形式用于分析 private
StringBuilder result = new
StringBuilder (); //输出的结果 private
int
seek; //分析文本时候的指针位置 private
string[] keepTag; //用于保存要保留的尖括号内容 private
bool
_inTag; //标记现在的指针是不是在尖括号内 private
bool
needContent = true; //是否要提取正文 private
string
tagName; //当前尖括号的名字 private
string[] specialTag = new
string[] { "script", "style", "!--"
}; //特殊的尖括号内容，一般这些标签的正文是不要的 /// <summary> /// 当指针进入尖括号内，就会触发这个属性。这里主要逻辑是提取尖括号里的标签名字 /// </summary> public
bool
inTag { get
{ return
_inTag; } set
{ _inTag = value; if
(!value) return; bool
ok = true; tagName = ""; while
(ok) { string
word = read (); if
(word != " "
&& word != ">") { tagName += word; } else
if
(word == " "
&& tagName.Length > 0) { ok = false; } else
if
(word == ">") { ok = false; inTag = false; seek -= 1; } } } } /// <summary> /// 初始化类 /// </summary> /// <param name="html"> /// 要分析的html代码 /// </param> public
HtmlParser (string
html) { htmlcode = new
string[html.Length]; for
(int
i = 0; i < html.Length; i++) { htmlcode[i] = html[i].ToString (); } KeepTag (new
string[] { }); } /// <summary> /// 设置要保存那些标签不要被过滤掉 /// </summary> /// <param name="tags"> /// /// </param> public
void
KeepTag (string[] tags) { keepTag = tags; } /// <summary> /// /// </summary> /// <returns> /// 输出处理后的文本 /// </returns> public
string
Text () { int
startTag = 0; int
endTag = 0; while
(seek < htmlcode.Length) { string
word = read (); if
(word.ToLower () == "<") { startTag = seek; inTag = true; } else
if
(word.ToLower () == ">") { endTag = seek; inTag = false; if
(iskeepTag (tagName.Replace ("/", ""))) { for
(int
i = startTag - 1; i < endTag; i++) { result.Append (htmlcode[i].ToString ()); } } else
if
(tagName.StartsWith ("!--")) { bool
ok = true; while
(ok) { if
(read () == "-") { if
(read () == "-") { if
(read () == ">") { ok = false; } else
{ seek -= 1; } } } } } else
{ foreach
(string
str in
specialTag) { if
(tagName == str) { needContent = false; break; } else needContent = true; } } } else
if
(!inTag && needContent) { result.Append (word); } } return
result.ToString (); } /// <summary> /// 判断是否要保存这个标签 /// </summary> /// <param name="tag"> /// A <see cref="System.String"/> /// </param> /// <returns> /// A <see cref="System.Boolean"/> /// </returns> private
bool
iskeepTag (string
tag) { foreach
(string
ta in
keepTag) { if
(tag.ToLower () == ta.ToLower ()) { return
true; } } return
false; } private
string
read () { return
htmlcode[seek++]; } } } |
原文：http://www.cnblogs.com/zfanlong1314/p/3532200.html