Error using Marshal.SizeOf on class with byte[][] type data on a class

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Hi.

I'm using this class:

C#

[StructLayout(LayoutKind.Sequential, Pack = 1)]
    class THolidayTz
    {
        public ushort ID;
        [MarshalAs(UnmanagedType.ByValArray, SizeConst = 4, ArraySubType = 0)]
        public byte[][] HDate = new byte[4][]; // Error using Marshal.SizeOf
        public ushort TZID;
    };

When I use a Marshal.SizeOf:

C#

byte[] buf = new byte[Marshal.SizeOf(Holiday)];

I got this error:

You can not marshal type "THolidayTz 'as unmanaged structure: one can not calculate any shift or significant size.

I see the error happens when I use a byte[][] definition, using:

C#

public byte[]HDate = new byte[4];

I don't Have error, but i Need to use byte[][]...

Thanks.

Posted 9-Nov-11 5:19am

Geca

Updated 9-Nov-11 5:25am

Mehdi Gholam

v2

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Squiggs · Answer 1 · 2011-11-10T18:46:00

Solution 1

For unmanaged types that do no easily map to .NET types, it is generally recommended to represent them as IntPtr's while marshalling and manually parse the data after the call completes. It would be helpful if you were to provide the unmanaged structure and function stub.

Posted 10-Nov-11 18:46pm

Squiggs

Comments

Geca 11-Nov-11 3:27am

Can you show me the example for this case ?
Thanks

Member 8034530 · Answer 2 · 2011-11-12T03:23:00

Solution 2

hi,
you need to do just like this,

[MarshalAs(UnmanagedType.ByValArray, SizeConst = 4, ArraySubType = 0)]
public byte[][] HDate;

it will work.

because, in C#.Net for unmanaged type you can not use new like this...
public byte[]HDate = new byte[4];

Posted 12-Nov-11 3:23am

Member 8034530

Comments

Geca 14-Nov-11 3:55am

Hi. I Have the same error...

[StructLayout(LayoutKind.Sequential, Pack = 1)]
class THolidayTz
{
public ushort ID;
[MarshalAs(UnmanagedType.ByValArray, SizeConst = 4, ArraySubType = 0)]
public byte[][] HDate;
public ushort TZID;
};

Calling:

THolidayTz Holiday = new THolidayTz();
byte[] buf = new byte[Marshal.SizeOf(Holiday)]; // Error on Marshal.SizeOf