The regular expression is used to obtain the content in the HTML Tag. (Note: If the content contains a carriage return, please refer to the third example)

Several Methods for getting simple HTML Tag content
// ==================================== Begin1 ====================== ==========
// Test string
String strtmp = string. empty;
// Regular Expression
String tmpstr = string. empty;

// Retrieve the value of the matching item in the specified HTML Tag. regexoptions. ignorecase is case-insensitive, and regexoptions. multiline is case-insensitive,
// Tmpstr = "<title> ([^ <] *) </title>" // obtain the content between <title>

Strtmp = @ "<add key = 'ononstring' value = 'server = localhost; database = database name; uid = sa; Pwd =; pooling = true'/> ";
// Obtain the string between "database =" and ";": Database = (.*);
Tmpstr = "database = ([^;] *);";
Match titlematch = RegEx. Match (strtmp, tmpstr, regexoptions. ignorecase | regexoptions. multiline );

// The following example is used as a syntax reference to obtain the size value. The actual application may not be so complex.
Strtmp = "> <font color = 'red' size = 6> webform3 </font> <";
Tmpstr = @ "<(\ W + \ s + \ W + [=] + ['] + \ W + ['] + \ s + [size =] + \ D )> ";
Match titlematch = RegEx. Match (strtmp, tmpstr, regexoptions. ignorecase | regexoptions. multiline );


// Retrieve the matching Value
String tmpstrtitle = titlematch. Groups [1]. value;
// Replace all HTML tags on the HTML page
Label1.text = RegEx. Replace (label1.text. Trim (), "<. +?> "," ") +" ********* "+ Titlematch. Groups [1]. value;

// Determine whether the matching regular expression is successful
If (RegEx. Match (tmpstr, "<. +?> "). Success)
{
// Operation
}
// ==================================== End1 ======================== ==========

// ==================================== Begin2 ========================== ==========
String webdoccontent = "<a href = http://www.xxx.xxx/college/pages/default.htm target = _ blank> faculty </a> ";
// Explain the following regular expression: [\ s] indicates matching space characters, and "+" indicates connection
String strpattern = @ "A [\ s] + href = (? <Link> [^ \ s>] +) [^>] *> (? <Text> [^ <] *) </a> ";
// Obtain the text displayed by the link
Matchcollection matches = RegEx. Matches (webdoccontent, strpattern, regexoptions. ignorecase | regexoptions. Compiled );
Foreach (match nextmatch in matches)
{
String url = nextmatch. Groups ["Link"]. value. tostring (). Trim ();
String urltext = nextmatch. Groups ["text"]. value. tostring (). Trim ();
Response. Write (URL + "****");
Response. Write (urltext );
}
// ==================================== End2 ========================== ==========

// ==================================== Begin3 ========================== ==========
String strpagecontent = string. empty;
Streamreader srpage = new streamreader (@ "E: \ save.txt", system. Text. encoding. getencoding ("gb2312 "));
Strpagecontent = srpage. readtoend ();
Srpage. Close ();
// (\ S) * Indicates 0 or multiple space characters and carriage return characters, and * Indicates 0 or more matching characters. (.*?) Indicates all information except the carriage return.
Matchcollection titlematchs = RegEx. Matches (strpagecontent, "<TD width = \" 85% \ "class = \" common_text \ "> (\ s )*(.*?) (\ S )*(.*?) (\ S )*(.*?) (\ S )*(.*?) (\ S) *) </TD> ", regexoptions. ignorecase | regexoptions. multiline );
Int tmpnum = 0;
// The content set that meets the regular expression of the loop.
Foreach (match nextmatch in titlematchs)
{
++ Tmpnum;
Label1.text + = tmpnum + "<br> *****" + nextmatch. Groups [1]. value;
}
// ==================================== End3 ======================= ==========