[PROJ] Interface to PROJ from C#

[Paul Harwood]

I might have to apologize - I did not spot this was a continuation of a
previous email chain :) I don't know why the context was lost

On Fri, 6 Jan 2023 at 10:07, Paul Harwood <runette at gmail.com> wrote:

> HI
>
> Might I politely suggest that you should think about asking effective
> questions? It is not clear from this what you are actually asking.
>
> My interpretation is that the vcpkg thing is not the question (so it would
> be nice if that was not the start of the email - it is FYI info).
>
> It looks like you are asking for help with PInvoke and Proj in C#. That is
> not going to be an easy ask - since it is not a supported environment in
> Proj and PInvoke is at best a dark art.
>
> It is not clear from the question if proj_create_crs_to_crs is a method
> that works or one that does not work. If it does not work - what is the
> problem/error message?
>
> As a general note - what I do since I do not want to have an unsupported
> Pinvoke interface is to use GDAL. This has supported C# bindings and does
> expose at least some of the Proj functionality as the OSR ABI. Not an ideal
> solution but workable and supported.
>
> On Thu, 5 Jan 2023 at 20:27, Jason Dick <JasonD at thetranstecgroup.com>
> wrote:
>
>> I used vcpkg. I used the instructions from the web site:
>>
>> https://proj.org/install.html
>>
>> It did take me awhile to get it working because I needed to customize the
>> process. But now that the DLL is built by default, that's less necessary.
>>
>> I only use a handful of functions and there are some that I didn't know
>> how to convert to C#. Here's an example of one import that I use.
>>
>> private const String ProjDLL = "proj.dll";
>>
>> // PJ *proj_create_crs_to_crs(PJ_CONTEXT *ctx, const char *source_crs,
>> const char *target_crs, PJ_AREA *area)
>> [DllImport(ProjDLL, CallingConvention = CallingConvention.Cdecl, CharSet
>> = CharSet.Ansi, BestFitMapping = false, ThrowOnUnmappableChar = true)]
>> private static extern IntPtr proj_create_crs_to_crs(IntPtr ctx, String
>> source_crs, String target_crs, IntPtr area);
>> _______________________________________________
>> PROJ mailing list
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>> https://lists.osgeo.org/mailman/listinfo/proj
>>
>
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