Hi,

is [DllImport("coredll.dll", EntryPoint="ReadFile")] managed or not ?
If not, how come I find no sample that relate to the byte[] array
with marshal unmanaged to avoid memory buffer mismatch (none sequential 
memory area) ?


Thanks.

I don't understand the question.  It's clearly C#, which by definition is 
managed code.  Nearly all samples for it I would expect to use a byte[] 
parameter for the lpBuffer parameter, but I don't know what you mean by 
"marshal unmanaged" or "avoid memory mismatch".  Do you mean avoiding a 
pointer invalidation due to a GC compaction?  ReadFile is synchronous, so 
once your thread goes into the call, compaction can't occur until you return 
from it, so there's nothing inherently unsafe about the operation and 
pinning the inbound array isn't necessary (though pre-allocation is).


-- 

Chris Tacke, Embedded MVP
OpenNETCF Consulting
Managed Code in an Embedded World
www.OpenNETCF.com




"Empi"  wrote in message 
news:ej0oyDazHHA.5992@TK2MSFTNGP02.phx.gbl...

> Hi,
>
> is [DllImport("coredll.dll", EntryPoint="ReadFile")] managed or not ?
> If not, how come I find no sample that relate to the byte[] array
> with marshal unmanaged to avoid memory buffer mismatch (none sequential 
> memory area) ?
>
>
> Thanks.
>
>
>
> 

Thanks.

I didn't know if coredll.dll has it all managed or further depends on 
unmanaged api's.


"<ctacke/>" <ctacke[at]opennetcf[dot]com> wrote in message 
news:eyMJOIazHHA.1168@TK2MSFTNGP02.phx.gbl...

>I don't understand the question.  It's clearly C#, which by definition is 
>managed code.  Nearly all samples for it I would expect to use a byte[] 
>parameter for the lpBuffer parameter, but I don't know what you mean by 
>"marshal unmanaged" or "avoid memory mismatch".  Do you mean avoiding a 
>pointer invalidation due to a GC compaction?  ReadFile is synchronous, so 
>once your thread goes into the call, compaction can't occur until you 
>return from it, so there's nothing inherently unsafe about the operation 
>and pinning the inbound array isn't necessary (though pre-allocation is).
>
>
> -- 
>
> Chris Tacke, Embedded MVP
> OpenNETCF Consulting
> Managed Code in an Embedded World
> www.OpenNETCF.com
>
>
>
>
> "Empi"  wrote in message 
> news:ej0oyDazHHA.5992@TK2MSFTNGP02.phx.gbl...
>> Hi,
>>
>> is [DllImport("coredll.dll", EntryPoint="ReadFile")] managed or not ?
>> If not, how come I find no sample that relate to the byte[] array
>> with marshal unmanaged to avoid memory buffer mismatch (none sequential 
>> memory area) ?
>>
>>
>> Thanks.
>>
>>
>>
>>
>
> 

Coredll itself, the DLL, is native code, not managed.  You're platform 
invoking, P/Invoking, that call, which is the same call that a native C 
program running on the device would access if it were reading from a file.

Paul T.

"Empi"  wrote in message 
news:eUr9DaazHHA.600@TK2MSFTNGP05.phx.gbl...

> Thanks.
>
> I didn't know if coredll.dll has it all managed or further depends on 
> unmanaged api's.
>
>
> "<ctacke/>" <ctacke[at]opennetcf[dot]com> wrote in message 
> news:eyMJOIazHHA.1168@TK2MSFTNGP02.phx.gbl...
>>I don't understand the question.  It's clearly C#, which by definition is 
>>managed code.  Nearly all samples for it I would expect to use a byte[] 
>>parameter for the lpBuffer parameter, but I don't know what you mean by 
>>"marshal unmanaged" or "avoid memory mismatch".  Do you mean avoiding a 
>>pointer invalidation due to a GC compaction?  ReadFile is synchronous, so 
>>once your thread goes into the call, compaction can't occur until you 
>>return from it, so there's nothing inherently unsafe about the operation 
>>and pinning the inbound array isn't necessary (though pre-allocation is).
>>
>>
>> -- 
>>
>> Chris Tacke, Embedded MVP
>> OpenNETCF Consulting
>> Managed Code in an Embedded World
>> www.OpenNETCF.com
>>
>>
>>
>>
>> "Empi"  wrote in message 
>> news:ej0oyDazHHA.5992@TK2MSFTNGP02.phx.gbl...
>>> Hi,
>>>
>>> is [DllImport("coredll.dll", EntryPoint="ReadFile")] managed or not ?
>>> If not, how come I find no sample that relate to the byte[] array
>>> with marshal unmanaged to avoid memory buffer mismatch (none sequential 
>>> memory area) ?
>>>
>>>
>>> Thanks.
>>>
>>>
>>>
>>>
>>
>>
>
>