Hi
Can you help me with converting a VB6 Declare Function construct to C#
systax. I think it is in the form of



[DLLImport ("A.DLL")]
public extrn void someFunction(.....);

But I don't see the association between the 2 statements. Can someone
explain ?

THanks

Phil,

Well, the DllImport attribute tells the CLR what the name of the DLL is
to load to find the function in (as well as other information, like the .
The CLR will then use function information to figure out the signature of
the function and load it from the dll, and subsequently call it.

The "extern" keyword here, combined with the attribute indicates that
the function is found in an unmanaged DLL (there should be a static keyword
here as well).


--
- Nicholas Paldino [.NET/C# MVP]
- mvp@xxxxxx

"Phil Hunt" <aaa@xxxxxx> wrote in message
news:%23r$DHm2PJHA.4424@xxxxxx

> Hi
> Can you help me with converting a VB6 Declare Function construct to C#
> systax. I think it is in the form of
>
> [DLLImport ("A.DLL")]
> public extrn void someFunction(.....);
>
> But I don't see the association between the 2 statements. Can someone
> explain ?
>
> THanks
>

The dll i have that has many entry point. It seems like I have to repeat the
Import statement everytime I declare a different function. Is that a short
hand for that. Also in VB6 the Declare stmt associate the fucntion with the
dll. Can I do that in this contruct ?

Thanks again


"Nicholas Paldino [.NET/C# MVP]" <mvp@xxxxxx> wrote in
message news:OUdnZz2PJHA.3932@xxxxxx

> Phil,
>
> Well, the DllImport attribute tells the CLR what the name of the DLL is
> to load to find the function in (as well as other information, like the .
> The CLR will then use function information to figure out the signature of
> the function and load it from the dll, and subsequently call it.
>
> The "extern" keyword here, combined with the attribute indicates that
> the function is found in an unmanaged DLL (there should be a static
> keyword here as well).
>
>
> --
> - Nicholas Paldino [.NET/C# MVP]
> - mvp@xxxxxx
>
> "Phil Hunt" <aaa@xxxxxx> wrote in message
> news:%23r$DHm2PJHA.4424@xxxxxx

>> Hi
>> Can you help me with converting a VB6 Declare Function construct to C#
>> systax. I think it is in the form of
>>
>> [DLLImport ("A.DLL")]
>> public extrn void someFunction(.....);
>>
>> But I don't see the association between the 2 statements. Can someone
>> explain ?
>>
>> THanks
>>

>
>

Phil,

Yes, you are right, you have to make a new declaration for each function
that you want to use through the P/Invoke layer.

There is no shorthand for that, AFAIK.

The DllImport attribute is what associates the function declaration with
the DLL that it is located in. You have to repeat this for every
declaration as well.


--
- Nicholas Paldino [.NET/C# MVP]
- mvp@xxxxxx

"Phil Hunt" <aaa@xxxxxx> wrote in message
news:eHMj9O3PJHA.3932@xxxxxx

> The dll i have that has many entry point. It seems like I have to repeat
> the Import statement everytime I declare a different function. Is that a
> short hand for that. Also in VB6 the Declare stmt associate the fucntion
> with the dll. Can I do that in this contruct ?
>
> Thanks again
>
>
> "Nicholas Paldino [.NET/C# MVP]" <mvp@xxxxxx> wrote
> in message news:OUdnZz2PJHA.3932@xxxxxx

>> Phil,
>>
>> Well, the DllImport attribute tells the CLR what the name of the DLL
>> is to load to find the function in (as well as other information, like
>> the . The CLR will then use function information to figure out the
>> signature of the function and load it from the dll, and subsequently call
>> it.
>>
>> The "extern" keyword here, combined with the attribute indicates that
>> the function is found in an unmanaged DLL (there should be a static
>> keyword here as well).
>>
>>
>> --
>> - Nicholas Paldino [.NET/C# MVP]
>> - mvp@xxxxxx
>>
>> "Phil Hunt" <aaa@xxxxxx> wrote in message
>> news:%23r$DHm2PJHA.4424@xxxxxx

>>> Hi
>>> Can you help me with converting a VB6 Declare Function construct to C#
>>> systax. I think it is in the form of
>>>
>>> [DLLImport ("A.DLL")]
>>> public extrn void someFunction(.....);
>>>
>>> But I don't see the association between the 2 statements. Can someone
>>> explain ?
>>>
>>> THanks
>>>

>>
>>

>
>

Thanks for your help.

"Nicholas Paldino [.NET/C# MVP]" <mvp@xxxxxx> wrote in
message news:udZi6T3PJHA.4224@xxxxxx

> Phil,
>
> Yes, you are right, you have to make a new declaration for each
> function that you want to use through the P/Invoke layer.
>
> There is no shorthand for that, AFAIK.
>
> The DllImport attribute is what associates the function declaration
> with the DLL that it is located in. You have to repeat this for every
> declaration as well.
>
>
> --
> - Nicholas Paldino [.NET/C# MVP]
> - mvp@xxxxxx
>
> "Phil Hunt" <aaa@xxxxxx> wrote in message
> news:eHMj9O3PJHA.3932@xxxxxx

>> The dll i have that has many entry point. It seems like I have to repeat
>> the Import statement everytime I declare a different function. Is that a
>> short hand for that. Also in VB6 the Declare stmt associate the fucntion
>> with the dll. Can I do that in this contruct ?
>>
>> Thanks again
>>
>>
>> "Nicholas Paldino [.NET/C# MVP]" <mvp@xxxxxx> wrote
>> in message news:OUdnZz2PJHA.3932@xxxxxx

>>> Phil,
>>>
>>> Well, the DllImport attribute tells the CLR what the name of the DLL
>>> is to load to find the function in (as well as other information, like
>>> the . The CLR will then use function information to figure out the
>>> signature of the function and load it from the dll, and subsequently
>>> call it.
>>>
>>> The "extern" keyword here, combined with the attribute indicates that
>>> the function is found in an unmanaged DLL (there should be a static
>>> keyword here as well).
>>>
>>>
>>> --
>>> - Nicholas Paldino [.NET/C# MVP]
>>> - mvp@xxxxxx
>>>
>>> "Phil Hunt" <aaa@xxxxxx> wrote in message
>>> news:%23r$DHm2PJHA.4424@xxxxxx
>>>> Hi
>>>> Can you help me with converting a VB6 Declare Function construct to C#
>>>> systax. I think it is in the form of
>>>>
>>>> [DLLImport ("A.DLL")]
>>>> public extrn void someFunction(.....);
>>>>
>>>> But I don't see the association between the 2 statements. Can someone
>>>> explain ?
>>>>
>>>> THanks
>>>>
>>>
>>>

>>
>>

>
>