I have an application that creates string templates with named variables. This is done in accordance to the logging guide for ASP.NET Core

Now I find myself wanting to deliver these strings through the API itself as well, but this time with all the parameters filled in.

Basicly I'd want to use:

var template = "ID ID not found";
var para = new object[] "value";
String.Format(template, para);

However this gives an invalid input string.
Ofcourse I also cannot guarantee that somebody din't make a string template the 'classic' way with indexes.

var template2 = "ID 0 not found";

Is there a new way of formatting strings that I'm missing or are we supposed to work around this ?

I do not want to rework the existing code base to use numbers or use the $"...para" syntax. As this would lose information when it is being logged.

I'm guessing I could do a regex search and see if there's a '0' or a named parameter, and replace the named with indexes before formatting. But I wanted to know if there are some easier/cleaner ways of doing this.

Update - regex solution:

Bellow is the current work-around I've made using regex

public static class StringUtils
 
 public static string Format(string template, params object[] para)
 
 var match = Regex.Match(template, @"@?w+");
 if (!match.Success) return template;

 if (int.TryParse(match.Value.Substring(1, match.Value.Length - 2), out int n))
 return string.Format(template, para);
 else
 
 var list = new List<string>();
 var nextStartIndex = 0;
 var i = 0;
 while (match.Success)
 
 if (match.Index > nextStartIndex)
 list.Add(template.Substring(nextStartIndex , match.Index - nextStartIndex) + $"i");
 else
 list.Add($"i");

 nextStartIndex = match.Index + match.Value.Length;

 match = match.NextMatch();
 i++;
 

 return string.Format(string.Join("",list.ToArray()), para);