Jun

6

Spatial Database for Postgres and ArcGis users: how to choose

Filed on June 6th, 2008 at 5:45 pm under , , , , , , , , , , , | 13 Comments 

As many of you can have already read, ArcSde for Postgres is coming out at ArcGis 9.3 (it is currently in the release candidate state). It will let you store geometries in two formats, Esri geometry and PostGis geometry, in the same fashion ArcSde for Oracle is letting Esri or Oracle geometries be stored.
I have seen some interest in the GIS community about this new, and i was reading interesting posts by Bill Dollins, Paul Ramsey, James Fee and Dave Bouwman, so I thought i would post here my opinion. Plus, as some of you may already know, zigGis 2.0 is out, so I am very interested in understanding where it would be better to use one (ArcSde) or the other (zigGis 2.0) solution.

First let me introduce you my point of view: i am since the ARC/INFO era a great fan of Esri software, and I am one of the many users in the GIS community saying that Esri is much much better vs Open Source in the GIS desktop products sector.
In fact, while also in the GIS OS scenario there are good products like QGIS, uDig, gvSIG (and some other), in my opinion no one of them still can even fairly reach what ArcGis Desktop and its extensions can actually do (with the big limit that you can use it only in a Microsoft box, but that is another story).
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Mar

21

zigGis 1.2 released

Filed on March 21st, 2007 at 7:44 pm under , , , | 7 Comments 

zigGIS 1.2, the Open Source ArcGis Desktop's connector to PostGIS, has just been released and you can download it here.

ArcMap with PostGis data using zigGis

This is a major release, as far it implements new important features like selections and rendering. At this time editing is still not supported (so it is still a read only connector).
Also ArcMap documents persistence is now fully supported, meaning that you can save your mxd document with your PostGIS layer in them, and then open them again without problems.
zigGis should correctly work with ArcGis 9.0 (sp3), 9.1 and 9.2. Before installing it don't forget to install .NET support for ArcGis.

the ArcMap toc with PostGis data using zigGis

Here is a list of supported and unsupported features in ArcMap with zigGis 1.2:

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Feb

21

PostGis WorkspaceFactory

Filed on February 21st, 2007 at 5:58 pm under , , , , , , , | 2 Comments 

In my previous post I have showed you how to install and using zigGIS for adding PostGIS data into ArcMap.
From the ArcMap user interface you just need to press the zigGIS button and an "Add PostGIS data" dialog will be shown to you. From there you can set a zig File path, where PostGIS connections settings are stored, and then a PostGIS layers list will be shown and you can check which layer(s) add to the map.

Add PostGis data

In this post I will show how to programmatically use zigGIS and ArcObjects to add PostGIS data into ArcMap.
zigGIS is a Microsoft .NET 2.0 library that can be used from .NET clients and also from COM clients.
You could use it in your ArcObjects .NET applications/library to manage PostGIS data, in any .NET language like VB .NET and C#.
As zigGIS it is obviously exposed to COM (ArcObjects are in COM), you could also use it in your COM applications/library, for example in applications developed with Visual Basic 6 and ArcMap's VBA (Visual Basic for Application).
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Feb

14

Installing zigGIS 1.1 for connecting ArcMap to PostGIS layers

Filed on February 14th, 2007 at 8:04 pm under , , , , , , , | 1 Comment 

zigGIS is an Open Source PostGIS connector for ArcGIS Desktop, that enables ArcMap to add PostGIS layers in the map.
Differently from other kinds of connectors, like for example PGArc, the very nice feature of zigGIS is the direct-read of PostGIS data, without the needs of proxy shapefiles. This meaning that the PostGIS features are directly readed and displayed in ArcMap from the PostGIS data source without a previous conversion to a shapefile or personal GDB.

zigGIS interface

This is a very interesting project, but still in a very early phase, in fact there are still important issues that are planned to be solved in the next future, like:
- edit features (edit PostGIS layer from ArcMap is still not implemented, and it is read-only)
- symbology not working (only simple symbol rendering is currently working)
- selections are not supported
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Jan

4

COM ArcObject passed to .NET library: how to cast, access and debug it

Filed on January 4th, 2007 at 1:49 pm under , , , , , | Comments Off 

Generally when developing your .NET ArcObjects library you are managing all .NET objects, because the ArcObjects are wrapped by the RCW, Runtime Callable Wrapper (preferably created by Esri, using the Primary Interoperability Assemblies, PIA, installed with ArcGIS desktop in the GAC).
You can then expose your .NET library to COM by a CCW, COM callable wrapper, creating a tlb with regasm (automatically done using Visual Studio if you check the 'Register for COM interop' option, under the Build tag of project's property dialog).

Using the RCW ArcObjects we are always using Managed code, so we don't get in troubles.

But what if a COM ArcObject is calling a method, sinking an event, or setting/getting a property from our .NET library?
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