【转帖】problem exploding blockref containing attributes
 

problem exploding blockref containing attributes
problem exploding blockref containing attributes
i am trying to read an dwg file that contains two block references. each block reference contains 2 attributes:
block1 - tag: 15124, value: 2990 and tag: u, value 1
block2 - tag: 15124, value: 2990 and tag: u, value 2
when i use an attribute iterator on the original block reference, i get the correct tags and values.
since we write our own drawing code, i explode the block reference to get the contained objects. this yields 2 omdbattributedefinition objects (in addition to the other parts of the block). when i load the omdbattributedefinition objects, however, i get the following attribute data:
block1 - tag: 3, value: <empty> and tag: u, value 1
block2 - tag: 3, value: <empty> and tag: u, value 2
the tag on the first attribute is incorrect. any idea what might be causing this?
the code i use to read the attribute data is:
code:
cstring strtag = pdwgattrdef->tag().c_str();
cstring strvalue = pdwgattrdef->textstring().c_str();
i am using dwgdirect 1.13.2 (i didn't see any bug fixes in the 1.14.1 help file that seemed to apply to my situation), with windows xp pro and vc++ 6.0.
i have attached my test file.
thanks,
bob
attached files
this is "as designed". explode of block reference in autocad works in the same way.
block contains attribute definition entities and attributes attached to block reference are lost during explode.
sergey slezkin
then why does the explode produce two oddbattributedefinition objects, one of which contains the correct attribute information, and one that does not? i would think that if the attributes were truly lost during this process, the explode would not produce any attribute definition objects.
can i assume that the first oddbattributedefinition:osition() refers to the first attribute, and the second one refers to the second attribute? if so, then i collect the attribute data before the explode and apply it later.
thanks,
bob
explode does not produce attribute definitions. they present in block. these entities are used as templates for creating attributes than block reference is being created.
they are not displayed if they are non-contant and present in "normal" (non-layout) block.
attribute definition and corresponding attribute have the same tag. usually the order of definitions and attributes is the same but it may be not the case for non-acad-created files.
btw, multiple definitions (and attributes) may present with the same tag. in this situation their order is the only way to match them.
sergey slezkin