how to create a dynamic content (MText) to a dynamic BlockReference

[reithinger]

Hi,

I have a dynamic Blockreference. I want to have a MText that will be refresh wenn i "move" the dynamic Block. How can I make that ?

Another Question is why a BlockReference that contains the MText and the dynamic BlockReference in a dwg is not right clone to another DWG (the ObjectId is not the same in the old and new DWG)

Thanks for your help

Fabrice

[ActivistInvestor]

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@reithinger wrote:

Hi,

I have a dynamic Blockreference. I want to have a MText that will be refresh wenn i "move" the dynamic Block. How can I make that ?

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Fields? 

[reithinger]

The question is why it doesn't do when i make a wbClone from a dwg to another dwg.
it is a formula in the dynamic Block and this will be "loose" in the new DWG after the wbclone

[ActivistInvestor]

What you've written so far is somewhat vague and does not accurately convey the conditions, such as exactly where is the field, where is the object that's referenced from the field formula, etc., etc., and so on - too many unknowns.

Can you post a minimal example drawing file containing the field that is not behaving as you would expect when you use Wblock? 

[reithinger]

Hi, i have join a example.

when i use the wbclone function to copy from this dwg to my actual dwg, the formula (bottom left arrow) could not do...

[_gile]

Did you try to WBlockClone the BlockReference?

private static void WBlockCloneBlockReference(Database targetDatabase, string fileName, string blockName)
{
    using (var sourceDatabase = new Database(false, true))
    {
        sourceDatabase.ReadDwgFile(fileName, FileOpenMode.OpenForReadAndAllShare, true, null);
        var ids = new ObjectIdCollection();
        using (var tr = sourceDatabase.TransactionManager.StartTransaction())
        {
            var modelSpace = (BlockTableRecord)tr.GetObject(
                SymbolUtilityServices.GetBlockModelSpaceId(sourceDatabase), OpenMode.ForWrite);
            foreach (ObjectId id in modelSpace)
            {
                if (id.ObjectClass.Name == "AcDbBlockReference")
                {
                    var br = (BlockReference)tr.GetObject(id, OpenMode.ForRead);
                    var dynBtr = (BlockTableRecord)tr.GetObject(br.DynamicBlockTableRecord, OpenMode.ForRead);
                    if (dynBtr.Name == blockName)
                    {
                        ids.Add(id);
                        break;
                    }
                }
            }
            tr.Commit();
        }
        if (ids.Count == 0)
            return;
        var mapping = new IdMapping();
        sourceDatabase.WblockCloneObjects(ids, SymbolUtilityServices.GetBlockModelSpaceId(targetDatabase), mapping, DuplicateRecordCloning.Ignore, false);
    }
}

[ActivistInvestor]

This appears to be an issue with dynamic blocks. If you WBLOCK your block to a .DWG file and then try to insert it into another drawing, all fields in the table display ##### and the block editor reports that the field expressions contain invalid references.  This document (and another document it has a link to) seem to be trying to explain why, but IMO, this limitation shouldn't exist, as ObjectId references contained in formulas and field AcObjProp references should be translated, but that doesn't appear to be the case.

In short, if you cannot round-trip a block by writing it to a DWG file using WBLOCK, and then INSERT it into a new document, something is wrong.

[reithinger]

Hi Gile,

yes a use this Funktion, a global function for the Blockreference, but i don't make the test with br.DynamicBlockTableRecord

var dynBtr = (BlockTableRecord)tr.GetObject(br.DynamicBlockTableRecord, OpenMode.ForRead);
if (dynBtr.Name == blockName)
{
ids.Add(id);
break;
}

Hi ActivistInvestor, do you mean, something in my example is wrong or somthing in ACAD is wrong ?

[ActivistInvestor]

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@reithinger wrote:

Hi ActivistInvestor, do you mean, something in my example is wrong or somthing in ACAD is wrong ?

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The problem is your block definition. The fields in the table could not have been created via the UI, but appear to have been created by pasting the field expression, e.g.:

%<\AcObjProp Object(%<\_ObjId 2159733957328>%).Parameter(101).UserVariable>%

The ObjectId is the id of the block reference inserted into model space, which isn't valid. If you try to insert a field into the block's definition (in MTEXT or TEXT), you'll see that in the case of anything except for attribute definitions, the BlockPlaceHolder is not available. But what you've created is a field that references an insertion of the block in model space, which is not valid, and is the reason why you are having the issue with object references in your field expressions becoming invalid.

In the drawing you posted, if you copy one of the block references, and then try editing it, the displayed field values are not calculated from to the block insertion you're editing (the copy), because the block's definition contains references to the original block insertion that you copied, rather than the copy of that which you are editing.

You could use attribute definitions and attributes to display data derived from the owning block reference, that can vary with each insertion of the block, but you can't have a text field contained in a block's definition that displays different values that are based on the containing block reference's properties.