Unmanaged to managed structs in C# problem

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I'm receiving in c# a structure pointer from a c++ library callback


c++ structure

the packing is 1 

typedef 
{
int data1[8];
int data2[8];
int data3;
int data3;	
} SomeStruct;


in c# i have this equivalent 

[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Ansi, Pack = 1), Serializable]
public struct SomeStruct
{
	[MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
	public int[] data1
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 8)]
        public int [] data2;
        public int data3;
        public int data4;
};

What I have tried:

var data contains the right IntPtr  

SomeStruct ss = (SomeStruct )Marshal.PtrToStructure(pointer, typeof(SomeStruct));

But im getting garbage, what im doing wrong?, thanks

Posted 19-Jan-17 7:46am

lista

Updated 19-Jan-17 8:12am

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OriginalGriff · Answer 1 · 2017-01-19T08:12:00

Solution 1

Have you tried the UnmanagedType.LPArray attribute?

C#

[MarshalAs(UnmanagedType.LPArray, SizeConst = 8)]
public int[] data1

The example here uses it: Default Marshaling for Arrays[^] - search for "When a C-style array is imported" and look at the example under "Managed Signature"

Posted 19-Jan-17 8:12am

OriginalGriff

Comments

lista 19-Jan-17 15:02pm

i tried before and i get this "Arrays fields must be paired with ByValArray or SafeArray"

Im going to read the link you sent, thanks a lot