Latest Contributions by NeilClemmons

When you create a join in ArcMap, the join results in a table that is a combination of the two tables you've joined together.  This table is used as the display source for the layer.  If you want to add another join, then you need to join the table to the result of the first join.  This will result in a table that is the combination of all 3 tables.  You can do this by modifying your code to use the layer's display feature class instead of its feature class (IGeoFeatureLayer.DisplayFeatureClass).  If a layer has joins, then the display feature class will be the result of those joins.  Using it when joining a new table will keep all of the previous joins intact.  Removing a join is much more complicated if the layer has multiple tables joined to it.  You have to think of it as a chain of tables:  layer feature class -> first joined table -> second joined table -> third joined table, etc.  To remove a join you have to recreate all of the joins while leaving out the table you no longer want.  You can do this by accessing the layer's RelQueryTable collection.  This collection contains info about the tables that are joined to the layer.  I don't have an example handy so you'll have to search for one.  Basically, you would loop through the RelQueryTable collection and use each RelQueryTable to get the info you need to rejoin all of the tables.  When you get to the table you want to remove, just skip it and go on to the next table in the collection. ... View more

All you need to do is overload the method to accept a default value that allows you to specify the value you want returned in cases where the database value is null.         Public Shared Function DatabaseToDouble(ByVal value As Object, ByVal defaultValue As Double) As Double             If value Is DBNull.Value Then                 Return defaultValue             Else                 Return Convert.ToDouble(value)             End If         End Function ... View more

A simple solution to this problem is to create a class for reading and writing values to database fields.  Put the class into a common code library that you can reference in all of your projects. This is how you might write a method on that class for reading doubles:         Public Shared Function DatabaseToDouble(ByVal value As Object) As Double             If value Is DBNull.Value Then                 Return 0             Else                 Return Convert.ToDouble(value)             End If         End Function Here's how you would call it: Dim d As Double = whateverYouNamedThatClass.DatabaseToDouble(feature.Value(fieldIndex)) You would add a method to the class for each data type you need (string, int, boolean, etc). ... View more

All you need to do is keep up with your own collection of maps.  When a document is opened, load your collection from the document's maps collection.  You "hide" a map by removing it from the document's maps collection.  You "show" the map by adding the map from your collection back into the document's maps collection.  When a document is closed, load all of the maps from your collection back into the document's collection so that the document remains unchanged. ... View more

What are your labels based on?  For example, if you have labels turned on for a layer and your label field is set to "SomeField" then you will need to assign a value to "SomeField" when creating the feature.  Otherwise, the field will be null and no label will be generated for that feature. ... View more

You can manage the maps that are in a document via IMxDocument.Maps. ... View more

Call the FindField method on the feature class' Fields collection.  If it returns -1 then the field doesn't exist. ... View more

That's pretty much what I said to do:             Dim mapDocument As IMapDocument = New MapDocument             mapDocument.Open("C:\temp\myMap_v10.mxd")             DirectCast(mapDocument, IDocumentVersion).DocumentVersion = esriArcGISVersion.esriArcGISVersion93             mapDocument.SaveAs("C:\temp\myMap_v93.mxd")             mapDocument.Close() ... View more

See the IConstructCircularArc interface for the built-in ArcObjects methods. ... View more

Without knowing what your original coordinate system and coordinates are I can't tell you if those values are correct or not.  The results you're getting will be in decimal degrees since you are projecting into a geographic coordinate system.  Remember that when expressed as x, y coordinates of a point that x = longitude and y = latitude.  Longitude values range from 0 to 180 with positive values being measured East and negative values being measured West.  Latitude values range from 0 to 90 with positive values being measured North and negative values being measured South.  The coordinates you posted are near Vancouver, Canada. ... View more

You can get the extent of the feature class from IGeoDataset.Extent.  See the developer help for more info on what the envelope it returns actually is. ... View more

Use IFeatureSnapAgent2.HitType. ... View more