Thursday, October 18, 2012

Setting up C++ Project for Python/ArcGIS Use

This article will discuss setting up a Visual Studios 2010 project to create a DLL using C++ which can be called by python using ctypes.

 1. Open Visual Studios
 2. Create a new C++ Win32 Project
 3. Give it a name, example: simplepythoncpp
 4. Press next 
 5. Select ‘Dll’ for the type of project
 6. Here you’ll have a set of created header files (.h) and Source Files (.cpp)
 7. To use ArcObjects, you need to reference the com libraries.  To do this, you need to tell visual studios where these libraries are.  To set the location, do the follow:
      a. In the Solution explorer, right click and select properties
      b. Select ‘VC++ Directories’
      c. Click on ‘Library Directories’ 
      d. Select ‘Edit’
      e. Navigate to the ArcGIS 10.1 install directory and select the ‘com’ folder
 8. Staying in the properties, we need to enable ‘C++/CLI’ 
      a. Click on ‘Command Lin’
      b. Under ‘Additional Options’ type ‘/clr’
 9. Next we need to define some ‘Code Generation’ options
      a. Click on ‘Code Generation’
      b. Under ‘Basic Runtime Checks’ select ‘Default’
 10. Press ‘Apply’ button then ‘OK’
Let’s test our project changes.
 1. Open the ‘stdafx.h’ header file
 2. Leave the default #include statements, and type in the following:

#import "esriSystem.olb" raw_interfaces_only, raw_native_types, no_namespace, named_guids, exclude("OLE_COLOR", "OLE_HANDLE", "VARTYPE")

 3. Compile project
No errors should appear, so your project is setup correct.  
Where do you do from here? Well, all the libraries you need in this header file, and reference them in your .cpp file.  

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