Are there any concise rules about when you need to marshal data to WinAPI
calls, and when you don't? It appears that most times you can call WinAPI
calls directly from .NET without any preparation. For example

Declare Function OpenPrinter Lib "winspool.drv" Alias "OpenPrinterA" (ByVal
pPrinterName As String, ByVal phPrinter As Integer,
<MarshalAs(UnmanagedType.Struct)> ByRef pDefault As PRINTER_DEFAULTS) As
Integer

Dim tmpHandle As Int32
Dim msDeviceName as String = "MyPrinter"
OpenPrinter(msDeviceName, tmpHandle, 0)

However, some functions appear to require all kinds of fancy manipulation
before you get to call them--particularly ones which require structures or
arrays. (See http://www.codeproject.com/vb/net/printwatchvbnet.asp). Why
isn't .NET smart enough to handle this "under the covers", the way that VB6
is?

There are a couple of articles on MSDN which describe the capabilities /
limitations of Platform Invocation (P/Invoke) from .NETCF:-
http://msdn.microsoft.com/smartclien...ntrointerp.asp
http://msdn.microsoft.com/smartclien...advinterop.asp

Peter

--
Peter Foot
Windows Embedded MVP
http://www.inthehand.com | http://www.peterfoot.net

"Dan" <(E-Mail Removed)> wrote in message
news:FCE63829-AF20-404E-A6FB-(E-Mail Removed)...
> Are there any concise rules about when you need to marshal data to WinAPI
> calls, and when you don't? It appears that most times you can call WinAPI
> calls directly from .NET without any preparation. For example
>
> Declare Function OpenPrinter Lib "winspool.drv" Alias "OpenPrinterA"
> (ByVal
> pPrinterName As String, ByVal phPrinter As Integer,
> <MarshalAs(UnmanagedType.Struct)> ByRef pDefault As PRINTER_DEFAULTS) As
> Integer
>
> Dim tmpHandle As Int32
> Dim msDeviceName as String = "MyPrinter"
> OpenPrinter(msDeviceName, tmpHandle, 0)
>
> However, some functions appear to require all kinds of fancy manipulation
> before you get to call them--particularly ones which require structures or
> arrays. (See http://www.codeproject.com/vb/net/printwatchvbnet.asp). Why
> isn't .NET smart enough to handle this "under the covers", the way that
> VB6
> is?
>
>
>

Right, but the question was targeting the full framework I think...
I would say, read this:
http://www.amazon.com/exec/obidos/tg...glance&s=books

"Peter Foot [MVP]" <(E-Mail Removed)> wrote in message
news:%(E-Mail Removed)...
> There are a couple of articles on MSDN which describe the capabilities /
> limitations of Platform Invocation (P/Invoke) from .NETCF:-
> http://msdn.microsoft.com/smartclien...ntrointerp.asp
> http://msdn.microsoft.com/smartclien...advinterop.asp
>
> Peter
>
> --
> Peter Foot
> Windows Embedded MVP
> http://www.inthehand.com | http://www.peterfoot.net
>
> "Dan" <(E-Mail Removed)> wrote in message
> news:FCE63829-AF20-404E-A6FB-(E-Mail Removed)...
>> Are there any concise rules about when you need to marshal data to WinAPI
>> calls, and when you don't? It appears that most times you can call
>> WinAPI
>> calls directly from .NET without any preparation. For example
>>
>> Declare Function OpenPrinter Lib "winspool.drv" Alias "OpenPrinterA"
>> (ByVal
>> pPrinterName As String, ByVal phPrinter As Integer,
>> <MarshalAs(UnmanagedType.Struct)> ByRef pDefault As PRINTER_DEFAULTS) As
>> Integer
>>
>> Dim tmpHandle As Int32
>> Dim msDeviceName as String = "MyPrinter"
>> OpenPrinter(msDeviceName, tmpHandle, 0)
>>
>> However, some functions appear to require all kinds of fancy manipulation
>> before you get to call them--particularly ones which require structures
>> or
>> arrays. (See http://www.codeproject.com/vb/net/printwatchvbnet.asp).
>> Why
>> isn't .NET smart enough to handle this "under the covers", the way that
>> VB6
>> is?
>>
>>
>>
>
>