ExtensibleStorage Field of value type string[]

[Anonymous]

Hi all,

I've encountered a problem when I'm trying to store an array of string to a field in a schema using ExtensibleStorage. It throws an InvalidOperationExcpetion on myEntity.Set(myFieldName, myStringArray) saying "Unsupported type: System.String[]"

Pseudocode:

var schemaBuilder = new SchemaBuilder(myGuid);
schemaBuilder.AddArrayField("myFieldName", typeof(string));
var mySchema = schemaBuilder.Finish();

var myField = mySchema.GetField("myFieldName");
var myEntity = newEntity(mySchema);

myEntity.Set(myField, new string[] {"string1", "string2"});
//throws InvalidOperationException: Unsupported type: System.String[]"

Any one have an idea of what I'm doing wrong?

Cheers,

Eirik

[jeremytammik]

Dear Eirik,

Yes, absolutely. 

Please take a close look at the exact function signature of 

myEntity.Set(myField,...

You will immediately see that it does not take a system array argument, but a generic list, templated to contain strings.

myEntity.Set(myField,new List<string>(...

Please also consult the extensive list of extensible storage samples provided by The Building Coder:

http://thebuildingcoder.typepad.com/blog/about-the-author.html#5.23

It covers this topic and many others as well.

I hope this helps.

Cheers,

Jeremy

[Revitalizer · Accepted solution]

Hi,

what about setting an IList<string> instead of string[] ?

Revitalizer

[Anonymous]

Jeremy, 

Thank you for your answer.

When i try to use a generic list (List<string>) the following Exception is thrown

Unsupported type: System.Collections.Generic.List`1[[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]

I do think the method expects an Array, because in another function we have, we use an array of ElementIds (like new List<ElementId>{myElementId1, myElementId2}.ToArray(), which works like a charm. But a string array is not accepted.

Cheers,

Eirik

[Revitalizer]

Hi,

try to use an IList instead of a List. Note the leading "I" 😉

Revitalizer

[jeremytammik]

Thank you for your appreciation, and many thanks to Revitalizer for providing the more accurate answers!

Revitalizer is right.

As a computer programmer, we cannot ignore little details like that leading 'I'.

Also, please, in future do look at the samples provided.

This issue has been discussed before and is included in The Building Coder discussions as well.

Thank you!

Cheers,

Jeremy 

[Anonymous]

An IList worked perfectly 🙂

Thank you very much Revitalizer and Jeremy!

Cheers,

Eirik

PS: Out of curiosity: Why wouldn't a List<T> work, when an IList<T> does work? (Maybe not the right forum, I know)

[Revitalizer]

Hi eirik,

no idea why we need to use an IList.

But it says in the RevitAPI.chm:

"The types for containers are IList for arrays and IDictionary for maps"

It's on each of the pages of the Entity.Set() method overloads, see "Remarks".

So it's nearly an RTFM question 🙂

Revitalizer

[Anonymous]

Revitalizer,

It is definitley a RTFM question. My bad. In hindseight.

Btw, I really love when a manual is needed. And sarcarsm always works well on forums.

Cheers,

Eirik