CE C# Build Display Rules programmatically

salvatore montella said:

Could anyone tell me what is the exact way to build a rule condition from code?

More generally, I think we need advice on writing Expressions programmatically.  It's easy to get an Expression wrong, but hard to get diagnostic information (as you have found).

salvatore montella said:

string MyRuleCondition = $@"REFERENCE.References.Logical Name = {fieldValue}";"

It's not clear what you're writing in that statement...

• A literal string is prefixed with two special .NET modifiers $@
• The string is terminated with an additional quote after the semi-colon
• How do you assign that statement to an Expression?

Please write your actual code here so we can better understand what you have:  Use the Insert|Code button.

Jon Summers said:

It's not clear what you're writing in that statement...

It's clear in my opinion, it's standard C# syntax.

In my opinion @ is unnecessary, because there is nothing that requires to interpret the string literally, but it does not cause any issue.

With regards,

  Jan

Hi Jan,

I tried in various ways (as you can see in the attached code) but unfortunately nobody works (with or without $ or @)

//Attempt1
string MyRuleCondition = "REFERENCE.References.Logical Name = Attachment_1";

//Attempt2
string value = "Attachment_1";
string MyRuleCondition = "REFERENCE.References.Logical Name = "+ value;

salvatore montella said:

I tried in various ways (as you can see in the attached code) but unfortunately nobody works (with or without $ or @)

Hmmm :-(

I am not able to find my old code when I tried Display Rules, but I think it's about to find out how exactly the condition is stored when created manually.

BTW DisplayRule class is IDisposable, your code does not contain code respecting this fact.

Regards,

  Jan

salvatore montella said:

I tried in various ways

1. In your first screenshot, where you create manually a rule, the expression target is spelled Attchment_1 not Attachment_1.
2. It's possible that spaces around the = are not required, or confuse the expression parser.  Try...

string MyRuleCondition = "REFERENCE.References.Logical Name=Attchment_1";

Hi Jon.
Attachment_1, Attchment_1, Foo, TestName ... don't make a difference,
these are just the value of the logical name of the attachment.
The problem is that Microstation does not create the rule  and returns the error "Unrecognize Criteria",  not that Micorstation creates the rule and then cannot resolve it.
I also tried with the syntax you proposed and the result is always the same unfortunately

greetings, Salvio

Hi Jon.
Attachment_1, Attchment_1, Foo, TestName ... don't make a difference,
these are just the value of the logical name of the attachment.
The problem is that Microstation does not create the rule  and returns the error "Unrecognize Criteria",  not that Micorstation creates the rule and then cannot resolve it.
I also tried with the syntax you proposed and the result is always the same unfortunately

greetings, Salvio