Fwd: lpsolve55.cs [1 Attachment]

[Michael Bowerman]

---------- Forwarded message ----------
From: Michael Bowerman <michael.bowerman@...>
Date: Thu, Oct 22, 2009 at 10:43 AM
Subject: lpsolve55.cs
To: lp_solve@...


I have updated the lpsolve55.cs wrapper to handle arrays and return strings
properly.

[William H. Patton]

Can you give an example which shows how to use get_col_name correctly in the
C# caller?

Where does the new helper function intPtrToString(.) come into play?

 

        [DllImport("lpsolve55.dll", SetLastError=true)] public static extern
IntPtr get_col_name(IntPtr lp, int column);

 

        public static string intPtrToString(IntPtr str)

        {

            return Marshal.PtrToStringAnsi(str);

        }

 

Was previously in 5.5.0.15

        [DllImport("lpsolve55.dll", EntryPoint = "get_col_name",
SetLastError = true)] private unsafe static extern IntPtr get_col_name_c(int
lp, int column);

        public static string get_col_name(int lp, int column)

        {

            return (Marshal.PtrToStringAnsi(get_col_name_c(lp, column)));

        }

 

The issue is to dispose of the unsafe modifier.  Does your code work?

 

William

 

  _____  

From: lp_solve@... [mailto:lp_solve@...] On Behalf
Of Michael Bowerman
Sent: Thursday, October 22, 2009 10:47 AM
To: lp_solve@...
Subject: [lp_solve] Fwd: lpsolve55.cs [1 Attachment]

 

 

[Attachment(s) from Michael Bowerman included below]




 

---------- Forwarded message ----------
From: Michael Bowerman <michael.bowerman@
<mailto:michael.bowerman@...> gmail.com>
Date: Thu, Oct 22, 2009 at 10:43 AM
Subject: lpsolve55.cs
To: lp_solve@yahoogroup <mailto:lp_solve@...> s.com


I have updated the lpsolve55.cs wrapper to handle arrays and return strings
properly.

 

[Michael Bowerman]

It looks like I was working off version 5.5.0.9, woops!  The definition in
version 5.5.0.15 is better for string returns, since my version needs 2
function calls where 5.5.0.15 needs only 1.  I think the unsafe keyword is
unecessary due to the fact that the only pointers operated on are in C
unmanaged memory.
It looks like the strings and arrays are correct in 5.5.0.15 as well.  The
only real change that I see now is changing all the ``int lp'' to ``IntPtr
lp'' and all the functions that return ``int'' for an lprec should be
``IntPtr'' as well (e.g. make_lp, copy_lp, etc.).  IntPtr is holds the size
of a native pointer.  So, 64-bit might be truncated.

I have attached an updated copy based on the latest version.

Thanks.

_bowerman



On Thu, Oct 22, 2009 at 5:11 PM, William H. Patton <pattonwh@...>wrote:

>
>
>  Can you give an example which shows how to use get_col_name correctly in
> the C# caller?
>
> Where does the new helper function intPtrToString(…) come into play?
>
>
>
>         [DllImport("lpsolve55.dll", SetLastError=true)] public static
> extern IntPtr get_col_name(IntPtr lp, int column);
>
>
>
>         public static string intPtrToString(IntPtr str)
>
>         {
>
>             return Marshal.PtrToStringAnsi(str);
>
>         }
>
>
>
> Was previously in 5.5.0.15
>
>         [DllImport("lpsolve55.dll", EntryPoint = "get_col_name",
> SetLastError = true)] private unsafe static extern IntPtr
> get_col_name_c(int lp, int column);
>
>         public static string get_col_name(int lp, int column)
>
>         {
>
>             return (Marshal.PtrToStringAnsi(get_col_name_c(lp, column)));
>
>         }
>
>
>
> The issue is to dispose of the unsafe modifier.  Does your code work?
>
>
>
> William
>
>
>  ------------------------------
>
> *From:* lp_solve@... [mailto:lp_solve@...] *On
> Behalf Of *Michael Bowerman
> *Sent:* Thursday, October 22, 2009 10:47 AM
>
> *To:* lp_solve@...
> *Subject:* [lp_solve] Fwd: lpsolve55.cs [1 Attachment]
>
>
>
>
>
>
>
> ---------- Forwarded message ----------
> From: *Michael Bowerman* <michael.bowerman@...>
> Date: Thu, Oct 22, 2009 at 10:43 AM
> Subject: lpsolve55.cs
> To: lp_solve@...
>
>
> I have updated the lpsolve55.cs wrapper to handle arrays and return strings
> properly.
>
>
>
>  
>