用正则表达式替换模式的多个引用

Question

I have a string which is in the following form

$KL\U#, $AS\gehaeuse#, $KL\tol_plus#, $KL\tol_minus#

Basically this string is made up of the following parts

• $ = Delimiter Start
• (Some Text)
• # = Delimiter End
• (all of this n times)

I would now like to replace each of these sections with some meaningful text. Therefore I need to extract these sections, do something based on the text inside each section and then replace the section with the result. So the resulting string should look something like this:

12V, 0603, +20%, -20%

The commas and everything else that is not contained within the section stays as it is, the sections get replaced by meaningful values.

For the question: Can you help me with a Regex pattern that finds out where these sections are so I can replace them?

Answer 1

You need to use the Regex.Replace method and use a MatchEvaluator delegate to decide what the replacement value should be.

The pattern you need can be $ then anything except # , then # . We put the middle bit in brackets so it is stored as a separate group in the result.

\$([^#]+)#

The full thing can be something like this (up to you to do the correct appropriate replacement logic):

string value = @"$KL\U#, $AS\gehaeuse#, $KL\tol_plus#, $KL\tol_minus#";

string result = Regex.Replace(value, @"\$([^#]+)#", m =>
{
    // This method takes the matching value and needs to return the correct replacement
    // m.Value is e.g. "$KL\U#", m.Groups[1].Value is the bit in ()s between $ and #
    switch (m.Groups[1].Value)
    {
        case @"KL\U":
            return "12V";
        case @"AS\gehaeuse":
            return "0603";
        case @"KL\tol_plus":
            return "+20%";
        case @"KL\tol_minus":
            return "-20%";
        default:
            return m.Groups[1].Value;
    }
});

Answer 2

As far as matching the pattern, you're wanting:

\$[^#]+#

The rest of your question isn't very clear. If you need to replace the original string with some meaningful values, just loop through your matches:

var str = @"$KL\U#, $AS\gehaeuse#, $KL\tol_plus#, $KL\tol_minus#";

foreach (Match match in Regex.Matches(str, @"\$[^#]+#"))
{
    str = str.Replace(match.ToString(), "something meaningful");
}

beyond that you'll have to provide more context

Answer 3

are you sure you don't want to do just plain string manipulations?

var str = @"$KL\U#, $AS\gehaeuse#, $KL\tol_plus#, $KL\tol_minus#";

string ReturnManipulatedString(string str)
{
    var list = str.split("$");

    string newValues = string.Empty;

    foreach (string st in str)
    {
         var temp = st.split("#");
         newValues += ManipulateStuff(temp[0]);
         if (0 < temp.Count();
             newValues += temp[1];
    }
}