Question

Can somebody help me to get a content between [%= and %].

Answer 1

If there cannot be nested tags you can use the following regex:

\[%=(.*?)%]

The symbols mean the following:

\[    Match a literal [ character. The backslash is required otherwise [ would
      start a character class.
%=    Match %=
(.*?) Match any characters, non-greedy. i.e. as few as possible. The parentheses
      capture the match so that you can refer to it later.
%]    Match %] - Note that it is not necessary to escape ] here, but you can if
      you want.

Here’s how you could use it in C#:

string s = "sanfdsg[%=jdgashg%]jagsklasg";
Match match = Regex.Match(s, @"\[%=(.*?)%]");
if (match.Success)
{
    Console.WriteLine(match.Groups[1].Value);
}

Output:

jdgashg

Or to get multiple matches:

string s = "foo[%=bar%]baz[%=qux%]quux";
foreach (Match match in Regex.Matches(s, @"\[%=(.*?)%]"))
{
    Console.WriteLine(match.Groups[1].Value);
}

Output:

bar
qux

Note the string literal is written as @”…”. This means that the backslashes inside the string are treated as literal backslashes, and not escape codes. This is often useful when writing regular expressions in C#, to avoid having to double up all the backslashes inside the string. Here it doesn’t make much difference, but in more complex examples it will help more.