解读C＃中的规则表达式(正则表达式)

string p7 = "%([0-9A-Fa-f][0-9A-Fa-f])";

string r7 = Regex.Replace(t7, p7, HexConvert);

删除C语言中的注释（有待完善）

string t8 = @"

/*

* 传统风格的注释

*/

";

string p8 = @"

/\* # 匹配注释开始的定界符

.*? # 匹配注释

\*/ # 匹配注释结束定界符

";

string r8 = Regex.Replace(t8, p8, "", "xs");

删除字符串中开始和结束处的空格

string t9a = " leading";

string p9a = @"^\s+";

string r9a = Regex.Replace(t9a, p9a, "");

string t9b = "trailing ";

string p9b = @"\s+$";

string r9b = Regex.Replace(t9b, p9b, "");

在字符\后添加字符n，使之成为真正的新行

string t10 = @"\ntest\n";

string r10 = Regex.Replace(t10, @"\\n", "\n");

转换IP地址

string t11 = "55.54.53.52";

string p11 = "^" +

@"([01]?\d\d|2[0-4]\d|25[0-5])\." +

@"([01]?\d\d|2[0-4]\d|25[0-5])\." +

@"([01]?\d\d|2[0-4]\d|25[0-5])\." +

@"([01]?\d\d|2[0-4]\d|25[0-5])" +

"$";

Match m11 = Regex.Match(t11, p11);

删除文件名包含的路径

string t12 = @"c:\file.txt";

string p12 = @"^.*\\";

string r12 = Regex.Replace(t12, p12, "");

联接多行字符串中的行

string t13 = @"this is

a split line";

string p13 = @"\s*\r?\n\s*";

string r13 = Regex.Replace(t13, p13, " ");

提取字符串中的所有数字

string t14 = @"

test 1

test 2.3

test 47

";

string p14 = @"(\d+\.?\d*|\.\d+)";