Pass C# string to C++ and pass C++ result (string, char*.. whatever) to C#

by

What I’ve found to work best is to be more explicit about what’s going on here. Having a string as return type is probably not recommended in this situation.

A common approach is to have the C++ side be passed the buffer and buffer size. If it’s not big enough for what GetString has to put in it, the bufferSize variable is modified to indicate what an appropriate size would be. The calling program (C#) would then increase the size of the buffer to the appropriate size.

If this is your exported dll function (C++): 

extern "C" __declspec void GetString( char* buffer, int* bufferSize );

Matching C# would be the following:

void GetString( StringBuilder buffer, ref int bufferSize );

So to use this in C# you would then do something like the following:

int bufferSize = 512;
StringBuilder buffer = new StringBuilder( bufferSize );
GetString( buffer, ref bufferSize );

More Related Contents:

  1. Reversing the given string without using reverse function [closed]
  2. Why does Read interfere with ReadLine? [duplicate]
  3. Easiest way to read from and write to files
  4. Easiest way to split a string on newlines in .NET?
  5. Converting string to title case
  6. Most efficient way to remove special characters from string
  7. Converting string to double in C#
  8. Replace Multiple String Elements in C#
  9. Is there a C# case insensitive equals operator?
  10. How to remove all white space from the beginning or end of a string?
  11. Find Nth occurrence of a character in a string
  12. Replacing a char at a given index in string? [duplicate]
  13. Getting hash of a list of strings regardless of order
  14. Casting vs Converting an object toString, when object really is a string
  15. How does StringBuilder work internally in C#?
  16. How do I capitalize first letter of first name and last name in C#?
  17. Add offset to IntPtr
  18. Display Float as String with at Least 1 Decimal Place
  19. Delete last char of string
  20. How can I Unescape and Reescape strings in .net?
  21. how to solve Exception:Call was rejected by callee. (Exception from HRESULT: 0x80010001 (RPC_E_CALL_REJECTED)) in C#?
  22. Why is \ character being doubled in my @ string?
  23. string.Join on a List or other type
  24. How to sort list of Ip Addresses using c#
  25. String comparison – strA.ToLower()==strB.ToLower() or strA.Equals(strB,StringComparisonType)?
  26. Regular expression to find and remove duplicate words
  27. Adding a newline into a string in C#
  28. Using StreamReader to check if a file contains a string
  29. Send message to a Windows process (not its main window)
  30. How can I create all possible combinations for a set of words without repetition?

Leave a Comment