Runtime
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This question came up during last week's accelerator, and is part of the reason I spent creating the last post: is it possible to selectively unlock certain layers for the duration of commands that have been specified by the user? Let's take an example: you have layers that should remain locked, apart from when using the MOVE command (COPY and ERASE should not work). The approach I took was to maintain a dictionary mapping command names to lists of layers to unlock. When a command is launched – which we can tell using the Document.CommandWillStart event – we check whether…
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In the last post we saw a "general" function to erase all the entities in a drawing that fulfill a specified condition. We used it to erase all the zero-length lines in a drawing. But as I'd mentioned at the end, I thought there was an opportunity to generalize the mechanism even further. Here's what I came up with (and I've included a suggestion by Parrish Husband to create an additional extension method for Curve.IsZeroLength()). using Autodesk.AutoCAD.ApplicationServices; using Autodesk.AutoCAD.DatabaseServices; using Autodesk.AutoCAD.Geometry; using Autodesk.AutoCAD.Runtime; using System; namespace ZeroLengthEntities { public static class Extensions { /// <summary> …
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A question came in by email, yesterday, and despite having a few mini-projects in progress that were spawned during last week's event in Prague, I couldn't resist putting some code together to address it. The developer wanted to purge zero-length geometry: the simplest way to solve the problem is to run "_-PURGE _Z" at the command-line, but I saw this more as an opportunity to create a simple helper that would loop through all the entities in a drawing and erase any meeting a specified condition. In this case it would be curves with a length less than the global…
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A really interesting problem came up during an internal discussion, this week: someone wanted to launch the REFEDIT command on a selected xref and pre-select the entity found at the picked point. The entity that's part of the selected xref, of course. This turned out to be quite a tricky problem and yet one that could be solved with relatively few lines of code. The tricky parts were finding the right entity in the nested selection and then the corresponding entity in the xref. Here's the approach I ended up taking: Ask the user to selected a nested entity Get…
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After the last post, where we saw how to get the centroid of a Region, today we're going to use that information to place some text inside a detected space. To restate our process from last time: The user selects a point Call Editor.TraceBoundary() to determine the containing space Call Region.CreateFromCurves() with the resulting geometry Determine the centroid of the Region Check whether the centroid is actually inside the Region If it is, then generate some text to place (we could also have asked the user for this, of course)… … and then calculate the size of the text such…
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In the last post we introduced a static C# class containing extension methods for the ObjectId and Transaction classes. The new Transaction methods allow you to more easily "lock" objects, whether because they're "system" objects you want to keep around in every drawing or because they're objects that shouldn't be purged at whim by users. Under the hood, the implementation uses Xrecords stored in the Named Objects Dictionary that contain hard-pointer references to the various locked objects. This stops the PURGE command from removing them, but also allows us to check via Database.Purge() – or our new ObjectId.IsErasable() shortcut –…
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This is one of those topics that has been at the back of my mind for a number of years. Here's a question I received via a blog comment back in 2009: I was wondering if there's an easy way to modify the objects to purge. For example, if a particular text style was included in the drawing that I did not want to be purged. Can this easily be done? Here's how I responded, at the time: There are a couple of ways: You can maintain your own list of objects "to keep" and remove any items that are…
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This question came in as a blog comment on this previous post: Is possible to use Revision Cloud in this situation? Example: Creating a polyline/circle/ellipse then make it a revision cloud. It seemed to make sense to broaden the topic for the purposes of this blog post: how to pass an entity or entities to an AutoCAD command called via Editor.Command() or CommandAsync(). Since Editor.Command() was implemented in AutoCAD 2015, I've been a fan of the calling commands in AutoCAD application code. But I haven't actually covered the approach needed to send object information to commands via this function. Yes,…
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This interesting question came in by email from Igor, over the weekend: Let say I want to delete a layer by it's name. I can get ObjectId or LayerTabelRecord from the name, like LayerTable tLayers = (LayerTable) Transaction.GetObject(Database.LayerTableId,OpenMode.ForRead,false) LayerTableRecord ltRecord = (LayerTableRecord) Transaction.GetObject(tLayers.Item[Name],OpenMode.ForWrite,false); Now having LayerTableRecord how can I found out that this DBObject is not the built-in one? Like names '0' or 'DEFPOINTS'. Same goes for TextStyle (STANDARD) or layout (MODEL)….? I can't found any property regarding this, like IsBuiltIn. The IsPersistent property is no help. It's true that there isn't an IsBuiltIn property on AutoCAD objects… for block…
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Here's an interesting question that came in from Nick Gilbert via a blog comment: Is there a simple way to get the geometric extents of the group? As discussed in this previous post, the Group object in AutoCAD presents itself as a collection of geometric objects (or entities, in ObjectARX-parlance). But a Group, in itself, isn't a geometric object: it's an aggregator of objects that are. So there isn't – as Nick is clearly aware – a simple GeometricExtents property of the Group object. But we can access the contents of the Group and combine their various GeometricExtents, returning an…