[Proj] Environment variable et proj.4 vb wrapper

Eric Miller EMiller at dfg.ca.gov
Tue Aug 1 11:58:55 EDT 2006


That VB wrapper hasn't been updated to know about the
pj_set_searchpath() function.  I'm not sure if the pj_set_finder()
function will work.  You could try it.  See the AddressOf operator.  I
seem to recall it doesn't work due to calling convention issues.

If you can figure out how to change the PROJ_LIB environment variable
from within your VB program, that should work.  Just do it during
program startup before any proj.4 functions are called. Or, maybe, use a
batch file that launches your VB program and sets the PROJ_LIB
variable?

>>> gheysen.t at gmail.com 8/1/2006 1:19:04 AM >>>
Hello,

I have wrote a little program in vb to download and upload GPS data.
This
software use 2 specific functions to transform the data from WGS 84 to
Lambert 72 (Belgium) and from Lambert 72 to WGS 84. I want to replace
these
functions by the proj.4 vb wrapper so I can use this software in other
contry than Belgium. I have test, without problem, this wrapper with
the
file "exemple.mdb".

My problem is that I have Qgis installed and thus I have already a
"Proj_lib" environment variable. If user uninstall Qgis, the proj.4 is
uninstall. How can I have two versions of Proj.4 install on the same
computer. I have read than I can use pj_set_finder() or
pj_set_searchpath()
to override this environment variable. This function is it available
through
the vb wrapper ? If yes, how can I use this in vb ?

Thanks in advance.

Gheysen Thibaut.


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