在 C# 中读取 PVOID，我应该读取多少位？

Question

I'm reading from a USB packet that has a URB type. The URB header defined at http://msdn.microsoft.com/en-us/library/windows/hardware/ff540409(v=vs.85).aspx as

 struct _URB_HEADER {
    USHORT      Length;
    USHORT      Function;
    USBD_STATUS Status;
    PVOID       UsbdDeviceHandle;
    ULONG       UsbdFlags;
 };

How many bits should I be reading for the PVOID?

Answer 1

Since that's a pointer type, then it depends on your platform. 32 bits for x86; 64 bits for x64.

I'm not well-versed with those libraries but should you be using those fields though? The link you shared says "Reserved. Do not use".

Edit : Disregard the last statement. I just realized that the structure is just the header. Of course you need to know that field's size in order to get to the body. :)

Answer 2

Thanks for the comments - reading through them, it looks like using

 byte [] ptr_bytes = rdr.ReadBytes(System.IntPtr.Size);

will provide the size of the pointer correctly depending on the operating system.