Sizeof and structure and managed code

I just submitted a case to Ms at noon. The problem is described as follows:
(This is an open-source Excel file. Code It was originally written in VB.net, and I wrote it again in C. The API used in VB.net: fileput does not solve this problem. I wrote this myself, but it does not work .)

The followingMarshal. sizeof (VT)In this line of codeSizeIt should be2 + 2 + 1Instead of memory alignment6. How can I get5This value?

 

Private VoidFileput (system. valuetype VT)

{

IntSize = 0;

Size = marshal. sizeof (VT );

Intptr P = marshal. allochglobal (size );

Marshal. structuretoptr (Vt, P,True);

Byte[] Buf =New Byte[Size];

Marshal. Copy (p, Buf, 0, size );

FS. Write (BUF, 0, Buf. Length );

}

 

//Call code:

L = aformat [lindex]. length;

Cformat_record.opcode = 0x1e;

Cformat_record.length = (Short) (L + 1 );

Cformat_record.formatlength = (Byte) (L );

Fileput (cformat_record );

 

//Structure example

[Structlayoutattribute (layoutkind. Sequential, charset = charset. Auto)]

StructFormat_record

{

Public ShortOpcode;// 0x1e

Public ShortLength;// 1 + Len (Format)

[Financialas (unmanagedtype. u1, sizeconst = 1)]Public ByteFormatlength;// Len (Format)

}// Followed by the format-picture

After Ms replies to me, I will post the results to share with you.