Strange Results with Text Insert Field when using Item Type Definition

Try System.String.Format. Check help. 

System.String.Format ("{0:#.#}", System.Math.Round(System.Math.Sqrt(this.GetElement().Segments[0].DeltaX ^ 2  + this.GetElement().Segments[0].DeltaY ^ 2),1)) 

Hi Leonard. Thank you for the suggestion. I gave it a try, but unfortunately it produced the same incorrect result as I noted in my original post.

As best I can tell, the calculations are being performed correctly in my item types. As I mentioned above, the correct values show up through the element properties dialog. However, there is a bug or issue when attempting to display the item type definitions via the place text \ insert field method. Rather than the software just going and "looking" or "grabbing" the values from the element properties window for the corresponding item type definition, it seems like the software is attempting to re-calculate all the item type definitions and then decides to add an extra layer of rounding to the results before applying it to the graphical piece of text.

This is very frustrating. The correct value is there under the element properties window, but there is no easy way to display this information to the user, or an eventual client via a detail plan sheet, etc.

Hi Leonard. Thank you for the suggestion. I gave it a try, but unfortunately it produced the same incorrect result as I noted in my original post.

As best I can tell, the calculations are being performed correctly in my item types. As I mentioned above, the correct values show up through the element properties dialog. However, there is a bug or issue when attempting to display the item type definitions via the place text \ insert field method. Rather than the software just going and "looking" or "grabbing" the values from the element properties window for the corresponding item type definition, it seems like the software is attempting to re-calculate all the item type definitions and then decides to add an extra layer of rounding to the results before applying it to the graphical piece of text.

This is very frustrating. The correct value is there under the element properties window, but there is no easy way to display this information to the user, or an eventual client via a detail plan sheet, etc.

Matthew Ashby said:

System.Math.Round(

doesnt the  round part round the  answer, sorry I'm not  expert in the strings thing .. but hey wouldnt it  be better to use a data Field so you could define in the text as lenght  and set the number of decimal point and  have it associated to the element.. without using item types

Hi Lorys. I don't think Text Data Fields would work. Unless I am missing something, the data fields are sort of "dumb" objects that cannot be assigned to "read" or look up element properties. What I am chasing after is an "intelligent" text that can read information from my Item Type definitions (that have some basic math calculations performed within the expression builder of the item definition). If the user extends or shortens the line, then the corresponding text annotation value would update and report the new 2D length of the line element object (which will be a 3D line).

Stated another way...I am trying to create a custom Dimension Element, but instead of using the restricted options that are pre-defined (e.g., length, angle, radius) as part of the Dimension Elements, I want to "pull/grab" the result of an Item Type Definition. In theory this should work with Text \ Insert Field process, but as I have discovered, there seems to be a "bug". If possible, it would be nice for someone from Bentley to acknowledge this, and then get it added to the pending issue resolution list.

ok were saying the same thing  now without using item types, bring up the text editor  type Length2D= 

but next use the  insert field ( this is a text data field not an Edit Data Field old school tech)  and  choose  length option property  and set the decimal places then it will ask to assign the text to which element. once completed if you  lengthen or shorten the element by its grab handles  you will get the text to auto update.. Yes the item types  or tag method will allow you to do reports  but what other things do you want to report , total lengths of all lines ? can be  done by select by attributes and level or colour  to create selection or via vba but IMHO select by is easier.

look here example in ask inga ( they use area but  length for lines is available as well as radius for circles and arcs etc

 Text fields 

Enter Data Fields

Lorys said:

wouldnt it  be better to use a data Field

Data fields, as you probably know, are an antiquated method of speeding annotation.

Matthew Ashby said:

Unless I am missing something, the data fields are sort of "dumb" objects

Correct!

Item Types

Item Types were introduced with MicroStation CONNECT and have improved and grown less buggy over the years as new Updates are introduced.  Item Types let you attach data, or calculate data, about a DGN element, model or  file.

Item Instances

When you attach an Item Type to an element, or something else, it's termed an Item instance.  That instance is invisible, but you can see its value in the Element Properties dialog.

Text Fields

Also improved with MicroStation CONNECT are Fields. A field lets you materialise an Item instance by displaying its value as text. Unlike an Enter Data field, a Field is smart and updates automatically when the Item instance changed. That is what Matthew is attempting, and it mostly works but a glitch has appeared.

Matthew Ashby said:

If the user extends or shortens the line, then the corresponding text annotation value would update and report the new 2D length of the line element

That's what should happen and, in my experience, does happen.

Lorys said:

use the  insert field ( this is a text data field not an Edit Data Field old school tech)  and  choose  length option property

Yes, Fields can be used to display a DGN property as well as Item instance data. 

Reports

Lorys said:

the item types  or tag method will allow you to do reports

You can create a Report from DGN properties.  An element doesn't have to be tagged or have Item data to participate in a Report.  Here are examples of Reports.  The examples report on DGN properties.  They don't include Item Types because I wanted to dispel the misconception that Reports are only meant to work with Item Types.

Thanks  Jon I meant  insert Text field  not Edit Data Field which I later made clearer in the later post. The OP implied he tried  items  but was getting  rounding errors, and  was not working  right when pulling the grab handles.. thanks  for  pointing  out reports can be done without  items, I learnt  something new.