Why do we need DllImport ?

[suhaib]

Hi Guys

Besides for reasons which drive us into making API calls, why else would one need to use DllImport ? How different is this from adding a reference to a Library - creating instance of it and then using it ?? Please let me know.

Thanks

Suhaib

[Norfy]

Hi Suhaib,

Besides for reasons which drive us into making API calls, why else would one need to use DllImport ?

There are no other reasons! DllImport is required to identify methods in external "unmanaged" DLLs.

How different is this from adding a reference to a Library - creating instance of it and then using it?

This only works for .NET DLLs.

[darwen]

You forgot that you can use C++.NET to access unmanaged dlls or COM objects.

Actually, I made the point that it shouldn't exist - it promotes bad practice when people try to take shortcuts by just calling the Win32 functions that they know.

However, it would cripple the language in this respect.

Darwen.

[Norfy]

I know what you mean. Fortunately I do not have a Win32 API or even C++ background, so I only use them as a last resort.

Occasionally though it seems that useful functionality is "missing" from a given component or assembly. A recent example is being able to drag and drop Images cf. ImageList_Drag* API.

Anyone know if Microsoft will be filling the gaps in later releases?

[Mitre]

Anyone tha thas a good tutorial on how to use DllImport?

need to use a C++ dll given by I/O card supplier to be used in C#