Pass reference of struct in a list from managed to unmanaged code across dll

I am very new to C# and currently having some trouble with marshalling structs to C functions in a dll. The struct in question contains a few ints, float and one char* in C as follows:

struct Bin
{
    char* m_name;
    float m_start;
    float m_end;

    int m_OwnerID;
    int m_SelfID;
}

The corresponding C# struct defintion, I think should be:

public struct Bin
{
    public string m_name;
    public float m_start;
    public float m_end;

    public int m_OwnerID;
    public int m_SelfID;
}

I also implemented a parser/reader function in C# that reads a text file, creates the Bin objects and stores them in a List object, which is a class member of the main app class. At the same time, I want to pass references to each struct object in the list to a unmanaged C++ Class through a Dll function call so it can be referred to during other function calls without the need to duplicate data on the unmanaged side.

class ProgramMain
{
    public List<Bin> m_BinList;

    static void Main()
    {
        //Some functions calls

        //Fills up List<Bin>
        LoadBinData(string inFile);

        //Iterate each bin in list and pass reference to each bin to C++ class via
        //Dll Imported function
        PassPtrsToLibrary(); //???
    }

    public void LoadBinData(string inFile)
    {
         .....
    }

    public void PassPtrsToLibrary()
    {
        ????
    }

     /* PassByReferenceIn */
    [DllImport ("mylib")]
    public static extern 
       void PassBinPtrIn(ref Bin theBin);

    //Some other function that reads the stored Bin pointers' data and perform calculations
    [DllImport ("mylib")]
    public static extern 
       int ProcessBin();

} 

On the C dll side, internally a global C++ class object stores the pointer to each struct in a std::vector container:

BinManager theBinManager;

void PassBinPtrIn(Bin* theBin)
{
    theBinManager.AddBin(theBin);
}

void BinManager::AddBin(Bin* theBin)
{
    m_BinPtrList.push_back(theBin);//a std::vector<Bin*> type
}

However I am facing some problems when writing the PassPtrsToLibrary() C# sharo function. After adding the Bin struct into the list, I can never get the actual pointer or reference to the bin inside the list. I have tried Marshall.StructureToPtr but it always crash my application. 开发者_如何学CI also read that it is difficult to pass a managed string in struct as pointer/reference into C code. Please give me some help or advice as how to solve this problem. Thank you for reading this lengthy post.