Topic: Take me to your leader

[sinc]

Has anyone tried messing with leaders or dimensions in .NET?

I was trying to get to and modify the MText portion of a MLEADER, and not having any luck.  When I take a look at the MLeader.MText property, it's always a DBObject with ObjectId = 0, which means I haven't found any way to open it for writing.  Is there some trick I'm overlooking?

I was also playing with standard dimensions.  Now those are bizarre...  They seem to use an MText as well, but they seem to delete and recreate the MText every time the dimension is modified (even a simple drag to another location).  I was actually able to create something that can turn on background masks for standard dimensions, but they all get reset when the drawing is saved and reopened.  And there doesn't seem to be any way to get to the text part - there is no Dimension.MText method.  So I couldn't get anything useful to work.

[Chuck Gabriel]

Not sure about the first part, but for the second part, won't setting the Dimtfill property of the dimension do what you want?

[sinc]

Wow!  How long as that been in Autocad?  Why is it so hidden?  I couldn't even find a mention of it in the help, except for in the system variables, once I knew to search for DIMTFILL.

So, after a dimension is created, how do I turn the background mask on and off?  Or can I?

But yeah, that helps!  We've been drawing wipeouts behind all our dimensions.  Maybe I should tell the other guys this is a new feature I just added in the Sincpac, and not that it's something we've had in Autocad for a while...   

[Chuck Gabriel]

So, after a dimension is created, how do I turn the background mask on and off?  Or can I?

I thinks it's all in that one property.

Accesses the dimension background color state, which can be one of the following values:
0 means the background color is disabled
1 means the use background color from dimtfillclr
2 means the use drawing's background color

[sinc]

Yeah, but as far as I can tell, all that does is affect the setting for newly-created dimensions.

I was wondering if there's a way to turn the background mask on or off for dimensions that are already in the drawing.  As far as I can tell, the answer is no...

[Chuck Gabriel]

Yeah, but as far as I can tell, all that does is affect the setting for newly-created dimensions.

I was wondering if there's a way to turn the background mask on or off for dimensions that are already in the drawing.  As far as I can tell, the answer is no...

I pulled that information from the Managed API documentation for the Dimension class.  That implies to me that each Dimension object can have its background fill property set individually.

I don't think we are on the same wavelength here.  Either that, or I am overlooking something obvious.

[Glenn R]

It's an override on the individual dimension as well as being present when a style is created.

[sinc]

Oh, jeez.

In the properties, set "Fill Color" to "Background".  No wonder I never saw it.  I was busily looking for a property that was easily-understood, like "Background mask".

Gotta put on my Autodesk cap, and think about things in a "skew" fashion, and then it makes sense...

Use either DIMTFILL or "Fill Color" to turn on background masks for dimensions.  I would have found this years ago if it was clearly stated in the Help, or if it was named something better, but I got it now.  Better late than never, eh?   

OK, so now how about getting to the text component of MLEADERS via .NET?  Anyone tried that?  Had any luck?

[T.Willey]

I haven't looked at mleaders, but are the associated with a block?  If so, then you will have to change the mtext in the block definition.  Just a guess though.

[Chuck Gabriel]

OK, so now how about getting to the text component of MLEADERS via .NET?  Anyone tried that?  Had any luck?

I think the Annotation property gets you the ObjectId of the annotation object.

[Glenn R]

Sample code?

[sinc]

Like I stated in my first post, there is an MLeader.MText property which returns the MTEXT entity used by the MLEADER.  The only problem is that it always has ObjectID = 0, so if I try to edit it, I get an access violation error.  At least, I think that's why I get the crash.

[Glenn R]

The only problem is that it always has ObjectID = 0, so if I try to edit it, I get an access violation error.  At least, I think that's why I get the crash.

More than likely, as that equates to a null ObjectId, however it's a lot easier for people to test and try to get a solution if they have either:

A. Sample test code to recreate the problem or,
B. The actual code that is causing the crash.

Preferably both, depending on the circumstances/crash. Also, I can only assume by your sig that you're using Civ 3d 2009...is that correct?

[Glenn R]

Code: [Select]

[CommandMethod("tcgsMleader")]
public static void tcgsMleaderCommand()
{
Document doc = acadApp.DocumentManager.MdiActiveDocument;
Database db = doc.Database;
Editor ed = doc.Editor;

PromptEntityOptions promptEntOpts = new PromptEntityOptions("Select MLeader: ");
promptEntOpts.SetRejectMessage("Selected entity is not an MLeader!");
promptEntOpts.AddAllowedClass(typeof(MLeader), true);


PromptEntityResult promptEntRes = ed.GetEntity(promptEntOpts);
if (promptEntRes.Status != PromptStatus.OK)
return;

using (Transaction tr = db.TransactionManager.StartTransaction())
{
MLeader ml = tr.GetObject(promptEntRes.ObjectId, OpenMode.ForRead, true) as MLeader;
if (ml == null)
return;

if (ml.HasContent())
{

MText leaderMtext = ml.MText;
if (leaderMtext == null)
{
ed.WriteMessage("{0}Error: Failed to get MText object of MLeader!", System.Environment.NewLine);
return;
}

ml.UpgradeOpen();

leaderMtext.Contents = "Helloooo TheSwamp!";
ml.MText = leaderMtext;

}

tr.Commit();
}
}

From the ARX docs:

Acad::ErrorStatus

setMText(

const AcDbMText* pMText);

pMText Input the pointer of MText object.

Sets a MText object to mleader.

Mleader will not change the input pMText. It doesn’t mind whether the pMText is database resident too. It just copies the content and fields of input MText to itself.

Returns Acad::eOk if successful.

The keyword here is 'copies' when referenced to this:

AcDbMText *

mtext() const;

Gets a clone of mleader’s mtext content

User need to release the returned mtext.

Returns the cloned mtext. If there is no mtext content, it returns NULL.

Keyword there is 'cloned'. So, changing the MText object's contents won't do anything until you reassign, as the value returned for the MText is a 'clone'.


The code was developed in Vis Stud 2008 Express and using AutoCAD Map 2008 for testing.

[Glenn R]

BTW, this was tested in Map 2008 by starting Acad and in the initial blank drawing creating an MLEADER.
If this doesn't work in your test drawing, it's possibly an associativity issue...