c# - List String within a class -

I have a class with many public accessor , one of which is the list & Lt; String & gt; down it; My question is, this is:

In the code that gives the principle of this class, I am piping through a string in which many lines can be pi, so for each line of PI It's the list & lt; String & gt; Want to add in P

So I have tried to:

  instancenam.p.AddRange (string.Split (new four [] {':', ': '}) [2]);   
 which gives me the value of the second set in a string such as : 23A: TETCGR   
 When I run the code, Follow:  
 
  Error 1:   
  The best overloaded method for System.Collections.Generic.List.AddRange Matching (System.Collections.Generic.IEnumerable) has some invalid argument   
 
  Error 2:   
 Argument 1: Can not convert 'string' from 'system.clalls. GENERIC. INNAMERABLE '* *  
 
 I have scored but are confused with the reactions; -)  
 Forresh (in string strings) {// it needs to be seen that the length is greater than 3. If (str! = "4:" & amp; str! = "") {// tag name  
  if (str.StartsWith (":") {tag = str. Split (new four [] {':', ':'}) [1]; SavedTag = tag; Switch (message type) {// tag 13c time signal if (tag == "13c") {mt202.tag13C.Add (str.Split (new four [] {':', ':'}) [2] ); } break; }   
 OK, so due to being nominated, I now have the following:   
 Edit:  
  Public category MT202 {public string tag20 {get; Set; } Public string tag21 {get; Set; } Public listing & lt; String & gt; Tag 13C {Get; Set; } Public string tag 32A {get; Set; } Public string tag 33B {get; Set; }} // below call calling class if (tag == "13c") {char [] delimiters = new char [] {':', ':'}; String [] splitValues ​​= str.Split (delimiter); String Single Value = Split Value [2]; & Lt; String & gt; Mt202.tag13C = New list & lt; String & gt; (); Mt202.tag13C.Add (singleValue); // mt202.tag13C.Add (str.Split (new four [] {':', ':'}) [2]);    
 
 
 Let's break this line:  
  Instancenam.p.AddRange (string.Split (new four [] {':', ':'}) [2]);   
 I think the  string  part is actually the name of a variable ( string  is not a valid identifier). I'll call  text  below.  
 The expanded code looks like this:  
  char [] delimiters = new char [] {':', ':'}; String [] splitValues ​​= text.Split (delimiter); String Single Value = Split Value [2]; & Lt; String & gt; List = instancenam.pee; List.AddRange (singleValue);   
 This will give the same error, because you are calling  AddRange , which is to assume the values ​​ archive  - but You are only providing a  single  price if you want to add only one value, then  add :  
  instancenam.p. Add (text. Split (new four [] {':', ':'}) [2]);   
 I recommend breaking the code that something like  bit  above the code given above - it is possible that it does not break down, but at least . (You can make a readable stable field for the delimiter to get started.)  
 Additionally, I can change the name of your property to something more meaningful than  p  PascalCase recommends for .net naming conventions.  
 EDIT: Now the post has been edited with:  
 
 I use the above mentioned object to render an instance of an object   
 It suggests that either  mt202  or  mt202.tag13C  is a  null  reference, but we can not tell you Should look with the debugger.