passing array of structs from c# to regular dll

Posted by buzz on Stack Overflow See other posts from Stack Overflow or by buzz
Published on 2009-11-19T02:54:07Z Indexed on 2010/03/31 6:03 UTC
Read the original article Hit count: 264

Filed under:

c#

|

arrays

|

passing

|

data-structures

Hi there I have a regular dll with the followign fucntion exported.

extern "C" __declspec(dllexport) int FindNearestStuff(double _latitude, double _longitude , LocationStruct * locations[])

LocationStruct is very simple

struct LocationStruct
  {
   long positionIndex;
   long item;
  };

I'm tryign to call it from c# using

 [DllImport("myclever.dll", CharSet = CharSet.None)]
        private static extern int FindNearestStuff(double _latitude, double _longitude, 
                                                    ref LocationStruct [] locations);

Its all cool and funky and i can step into the dll function from the debugger. Inside the dll the LocationStruct array is populated correctly and all is very good.

the problem i have is when it returns back from the dll, the LocationStruct array is not coming back with the data - just empty values...

what am i missing?

cheers

Buzz

© Stack Overflow or respective owner

Related posts about c#

.NET WebRequest.PreAuthenticate not quite what it sounds like

as seen on West-Wind - Search for 'West-Wind'
I’ve run into the problem a few times now: How to pre-authenticate .NET WebRequest calls doing an HTTP call to the server – essentially send authentication credentials on the very first request instead of waiting for a server challenge first? At first glance this sound like it should be easy:… >>> More
HttpWebRequest and Ignoring SSL Certificate Errors

as seen on West-Wind - Search for 'West-Wind'
Man I can't believe this. I'm still mucking around with OFX servers and it drives me absolutely crazy how some these servers are just so unbelievably misconfigured. I've recently hit three different 3 major brokerages which fail HTTP validation with bad or corrupt certificates at least according to… >>> More
Dynamic Type to do away with Reflection

as seen on West-Wind - Search for 'West-Wind'
The dynamic type in C# 4.0 is a welcome addition to the language. One thing I’ve been doing a lot with it is to remove explicit Reflection code that’s often necessary when you ‘dynamically’ need to walk and object hierarchy. In the past I’ve had a number of ReflectionUtils that used string based expressions… >>> More
The dynamic Type in C# Simplifies COM Member Access from Visual FoxPro

as seen on West-Wind - Search for 'West-Wind'
I’ve written quite a bit about Visual FoxPro interoperating with .NET in the past both for ASP.NET interacting with Visual FoxPro COM objects as well as Visual FoxPro calling into .NET code via COM Interop. COM Interop with Visual FoxPro has a number of problems but one of them at least got a lot… >>> More
Finding a Relative Path in .NET

as seen on West-Wind - Search for 'West-Wind'
Here’s a nice and simple path utility that I’ve needed in a number of applications: I need to find a relative path based on a base path. So if I’m working in a folder called c:\temp\templates\ and I want to find a relative path for c:\temp\templates\subdir\test.txt I want to receive back subdir\test… >>> More

Related posts about arrays

Arrays in php, Compare 2 arrays and keep duplicate values

as seen on Stack Overflow - Search for 'Stack Overflow'
The following is 2 different definitions of the problem: How can I process 2 arrays so that I can keep the data of duplicate array[key] values. I have arrays A and B. I want to create array C with the children that their id/key values exist in both A and B arrays. Thank you >>> More
commands&creating pointer [closed]

as seen on Stack Overflow - Search for 'Stack Overflow'
input 23 3 4 4 42 n 23 0 9 9 n n n 3 9 9 x //according to input,i should create int pointer arrays. pointer arrays // starting from 1 (that is initial arrays is arrays[1].when program sees n ,it // must be jumb to arrays 2 // the first int input 23 is num_arrays which used… >>> More
n & x commands&creating pointer&with using malloc [closed]

as seen on Stack Overflow - Search for 'Stack Overflow'
input 23 3 4 4 42 n 23 0 9 9 n n n 3 9 9 x //according to input,i should create int pointer arrays. pointer arrays // starting from 1 (that is initial arrays is arrays[1].when program sees n ,it // must be jumb to arrays 2 // the first int input 23 is num_arrays which… >>> More
reopen or read and say why not reopened [closed]

as seen on Stack Overflow - Search for 'Stack Overflow'
input 23 3 4 4 42 n 23 0 9 9 n n n 3 9 9 x //according to input,i should create int pointer arrays. pointer arrays // starting from 1 (that is initial arrays is arrays[1].when program sees n ,it // must be jumb to arrays 2 // the first int input 23 is num_arrays which used… >>> More
Fortran arrays and subroutines (sub arrays)

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm going through a Fortran code, and one bit has me a little puzzled. There is a subroutine, say SUBROUTINE SSUB(X,...) REAL*8 X(0:N1,1:N2,0:N3-1),... ... RETURN END Which is called in another subroutine by: CALL SSUB(W(0,1,0,1),...) where W is a 'working array'. It appears that a specific… >>> More