TheSwamp

Code Red => .NET => Topic started by: Coder on May 22, 2015, 06:48:12 AM

Title: Get line lengths
Post by: Coder on May 22, 2015, 06:48:12 AM
Hello guys ,

I am having an error with the variable len just inside the foreach function , can anyone tell me why I have this error ?

Thanks

Code - C#: [Select]
  1. [CommandMethod ("getlen")]
  2.         public static void LineLengths()
  3.         {
  4.             Document Adoc = Application.DocumentManager.MdiActiveDocument;
  5.             Database db = Adoc.Database;
  6.             Editor ed = Adoc.Editor;
  7.             double len;            
  8.             ed.WriteMessage("\nSelect Lines: ");
  9.  
  10.             TypedValue[] Tvals = new TypedValue[] { new TypedValue(0, "LINE") };
  11.             SelectionFilter ssf = new SelectionFilter(Tvals);
  12.             PromptSelectionOptions opt = new PromptSelectionOptions();
  13.             PromptSelectionResult psr = ed.GetSelection(opt, ssf);
  14.          
  15.             if (psr.Status == PromptStatus.OK && psr.Value.Count > 0)
  16.                 using (Transaction trans = db.TransactionManager.StartTransaction())
  17.                 {
  18.                     foreach (SelectedObject item in psr.Value)
  19.                     {                
  20.                         Line line = (Line)trans.GetObject(item.ObjectId, OpenMode.ForWrite);
  21.  
  22.                         len += line.Length; /// <-- this len variable shows as an error
  23.                     }
  24.                     ed.WriteMessage("Lengths of line(s) :" + len.ToString());
  25.                     trans.Commit();
  26.                 }
  27.         }
Title: Re: Get line lengths
Post by: Kerry on May 22, 2015, 07:10:07 AM
Go into debug mode, put a breakpoint at the line = statement, check your variable values as you iterate the psr .. that may help.

BTW .
A cheaper process is to declare the line variable outside the loop and just assign a value as you iterate rather than declare and assign at each step

... and more importantly ... why are you forcing the getObject to a Line ... doesn't your selection process ensure that it is a line ??

added: and why are you setting OpenMode to ForWrite ??
Title: Re: Get line lengths
Post by: gile on May 22, 2015, 07:16:36 AM
Hi,

When (or where) do you call tr.Commit() ?
Title: Re: Get line lengths
Post by: Coder on May 22, 2015, 07:28:54 AM
Hello Kerry ,
I am assigning a new line object in the looping process to get length property and that is the only way that I know for far .

Hello gile,
I know that the commit is not need in this program because we have no new objects added by these codes.

And the reason why it was there is that I started writing the program from another program and forgot to remove it from the new program .
Title: Re: Get line lengths
Post by: Kerry on May 22, 2015, 07:36:19 AM
Coder,
You are incorrect on both counts.
Read again exactly what I wrote. There is a distinction between multiple assigning and multiple declaring/assigning.

Commit IS advantageous .. it is faster and safer. this has been the cause of many long discussions here and elsewhere over the last 10 or so years.
Title: Re: Get line lengths
Post by: gile on May 22, 2015, 08:32:41 AM
Coder,

First, forgive my reply, I misread your code.

Second, follow Kerry's advices.

Third, let your cursor on the len variable (in the line the error occurs), visual studio should display a tooltip which tells you what kind of error...
Title: Re: Get line lengths
Post by: Coder on May 22, 2015, 12:25:53 PM
Hi,

I can not run the program because I receive a message  (There were build errors . Would you like to .... etc  Yes / No)

How to test the program in this case ?
Title: Re: Get line lengths
Post by: Jeff_M on May 22, 2015, 12:33:27 PM
You don't initialize the len symbol.
double len;

Change that to
double len= 0;
Title: Re: Get line lengths
Post by: Coder on May 22, 2015, 12:49:07 PM
Quote from: Jeff_M on May 22, 2015, 12:33:27 PM
You don't initialize the len symbol.
double len;

Change that to
double len= 0;

Hi Jeff_M
I have had a headache of this error since yesterday and now everything is settled down. :-D

Thank you so much .
Title: Re: Get line lengths
Post by: gile on May 22, 2015, 12:49:54 PM
Quote from: Coder on May 22, 2015, 12:25:53 PM
Hi,

I can not run the program because I receive a message  (There were build errors . Would you like to .... etc  Yes / No)

How to test the program in this case ?

To do what I suggested, you do not need to run the program. Most "edition time" errors are shown by Visual Studio underlining the error with a wavy red line.
Title: Re: Get line lengths
Post by: Coder on May 22, 2015, 12:59:47 PM
Quote from: gile on May 22, 2015, 12:49:54 PM
To do what I suggested, you do not need to run the program. Most "edition time" errors are shown by Visual Studio underlining the error with a wavy red line.

Thank you gile , now I know the differences between assigning and declaring .
Thanks to Kerry also .

You guys are wonderful .

Title: Re: Get line lengths
Post by: Coder on May 22, 2015, 01:29:52 PM
Quote from: Kerry on May 22, 2015, 07:10:07 AM
Go into debug mode, put a breakpoint at the line = statement, check your variable values as you iterate the psr .. that may help.
I could not get into debug mode due to the error that is in the program .
Quote from: Kerry on May 22, 2015, 07:10:07 AM
BTW .
A cheaper process is to declare the line variable outside the loop and just assign a value as you iterate rather than declare and assign at each step
It is outside the loop process , is not it ?

Quote from: Kerry on May 22, 2015, 07:10:07 AM
... and more importantly ... why are you forcing the getObject to a Line ... doesn't your selection process ensure that it is a line ??
I could not come with an alternative one than this one , can you offer your idea please ?

Quote from: Kerry on May 22, 2015, 07:10:07 AM
added: and why are you setting OpenMode to ForWrite ??
Yes it supposed to be ForRead and not ForWrite , you are right .

Thank you.
Title: Re: Get line lengths
Post by: Keith Brown on May 22, 2015, 10:49:29 PM
Quote from: Coder on May 22, 2015, 01:29:52 PM
It is outside the loop process , is not it ?

No it is not.  You are declaring a new line every time you iterate the for loop.  You should declare the line outside the loop and then set its value each time through the loop like Kerry said.  Something like below.

Code - C#: [Select]
  1.             if (psr.Status == PromptStatus.OK && psr.Value.Count > 0)
  2.                 using (Transaction trans = db.TransactionManager.StartTransaction())
  3.                 {
  4.                     Line line;
  5.                     foreach (SelectedObject item in psr.Value)
  6.                     {                
  7.                         line = (Line)trans.GetObject(item.ObjectId, OpenMode.ForWrite);
  8.  
  9.                         len += line.Length; /// <-- this len variable shows as an error
  10.                     }
  11.                     ed.WriteMessage("Lengths of line(s) :" + len.ToString());
  12.                     trans.Commit();
  13.                 }
  14.             }
Title: Re: Get line lengths
Post by: Coder on May 23, 2015, 02:08:56 AM
Thank you Keith Brown , I got the point from your example .  :-)