function pointer

[Lance Johnson]

I'm using an external DLL that expects the address of a function for a
callback. How can I go about getting the address of a function I have?
Thanks for any help in this.

Lance Johnson

 

[Shakir Hussain]

you have to declare delegate

public delegate void TestCallback();

and pass it as a parameter to the function in DllImport.

[DllImport("Sample.dll")]
public static extern void SomeFunction(TestCallback callback);

 

[Lance Johnson]

Thanks for the reply. I believe this assumes it's just a regular function.
However, the function in the external DLL is a member function. Is there
anything special I have to do for that to work because I'm not just calling
a particular function but instead a function on an instance of some class.

Lance Johnson

you have to declare delegate

public delegate void TestCallback();

and pass it as a parameter to the function in DllImport.

[DllImport("Sample.dll")]
public static extern void SomeFunction(TestCallback callback);

--
Shak
(Houston)

I'm using an external DLL that expects the address of a function for a
callback. How can I go about getting the address of a function I have?
Thanks for any help in this.

Lance Johnson

 

[Shakir Hussain]

When you pass structures or callbacks to Api's using DllImport, you have to
create a Managed code by duplicating the structure or function in c#. You
have to use those to the function to handle things. Refer MSDN hpw to do
that.

--
Shak
(Houston)

Thanks for the reply. I believe this assumes it's just a regular function.
However, the function in the external DLL is a member function. Is there
anything special I have to do for that to work because I'm not just calling
a particular function but instead a function on an instance of some class.

Lance Johnson

you have to declare delegate

public delegate void TestCallback();

and pass it as a parameter to the function in DllImport.

[DllImport("Sample.dll")]
public static extern void SomeFunction(TestCallback callback);

--
Shak
(Houston)

I'm using an external DLL that expects the address of a function for a
callback. How can I go about getting the address of a function I have?
Thanks for any help in this.

Lance Johnson

 

[Lance Johnson]

I don't know what you mean by hpw and when I do a search for hpw it returns
nothing.

Lance Johnson

When you pass structures or callbacks to Api's using DllImport, you have to
create a Managed code by duplicating the structure or function in c#. You
have to use those to the function to handle things. Refer MSDN hpw to do
that.

--
Shak
(Houston)

Thanks for the reply. I believe this assumes it's just a regular function.
However, the function in the external DLL is a member function. Is there
anything special I have to do for that to work because I'm not just calling
a particular function but instead a function on an instance of some class.

Lance Johnson

you have to declare delegate

public delegate void TestCallback();

and pass it as a parameter to the function in DllImport.

[DllImport("Sample.dll")]
public static extern void SomeFunction(TestCallback callback);

--
Shak
(Houston)


I'm using an external DLL that expects the address of a function for a
callback. How can I go about getting the address of a function I have?
Thanks for any help in this.

Lance Johnson

 

[Shakir Hussain]

Sorry,

it was a typo, i meant

Refer MSDN how to do that

--
Shak
(Houston)

I don't know what you mean by hpw and when I do a search for hpw it returns
nothing.

Lance Johnson

When you pass structures or callbacks to Api's using DllImport, you have to
create a Managed code by duplicating the structure or function in c#. You
have to use those to the function to handle things. Refer MSDN hpw to do
that.

--
Shak
(Houston)

Thanks for the reply. I believe this assumes it's just a regular function.
However, the function in the external DLL is a member function. Is there
anything special I have to do for that to work because I'm not just calling
a particular function but instead a function on an instance of some class.

Lance Johnson


you have to declare delegate

public delegate void TestCallback();

and pass it as a parameter to the function in DllImport.

[DllImport("Sample.dll")]
public static extern void SomeFunction(TestCallback callback);

--
Shak
(Houston)


I'm using an external DLL that expects the address of a function

for

a

 

[Sunny]

You may try to search in the framework.interop newsgroup as well.

Sunny

 

[Willy Denoyette [MVP]]

If your "function" is a method of a native C++ class in an external DLL,
then you can't call it directly.
One possible option is to create a managed wrapper class using VS2003's
Managed Extentions for C++ and populate the class with thunk methods that
invoke the associated native method(s).

Willy.

Thanks for the reply. I believe this assumes it's just a regular
function.
However, the function in the external DLL is a member function. Is there
anything special I have to do for that to work because I'm not just
calling
a particular function but instead a function on an instance of some class.

Lance Johnson

you have to declare delegate

public delegate void TestCallback();

and pass it as a parameter to the function in DllImport.

[DllImport("Sample.dll")]
public static extern void SomeFunction(TestCallback callback);

--
Shak
(Houston)

I'm using an external DLL that expects the address of a function for a
callback. How can I go about getting the address of a function I have?
Thanks for any help in this.

Lance Johnson