Need to convert to web application before converting website project

[ortrails]

Steps to reproduce

1. In Visual Studio 2019 open up a Web Application project that contains VB code.
2. Run the "Convert to C#" command
3. See error

Error message shown

#error Cannot convert ClassBlockSyntax - see comment for details
/* Cannot convert ClassBlockSyntax, CONVERSION ERROR: Object reference not set to an instance of an object. in 'Partial Class index_createM...' at character 206
at ICSharpCode.CodeConverter.CSharp.HandledEventsAnalyzer.CreateEventContainer(EventContainerSyntax p, SemanticModel semanticModel)
at ICSharpCode.CodeConverter.CSharp.HandledEventsAnalyzer.<>c__DisplayClass11_0.b__2(MethodStatementSyntax _, HandlesClauseItemSyntax e)
at System.Linq.Enumerable.d__233.MoveNext() at System.Linq.Enumerable.<SelectManyIterator>d__172.MoveNext()
at System.Linq.Enumerable.d__17`2.MoveNext()

Details

• Product in use: VS Extension
• Version in use: 9.1.1.0

[GrahamTheCoder]

Thanks for the report. Somewhere in one of the parts of the partial class indicated (index_CreateM....) there must be a Handles clause with an event container that the converter can't find the symbol for.

I suspect it's this line throwing:

CodeConverter/CodeConverter/CSharp/HandledEventsAnalyzer.cs

Line 105 in 7a4bcd1

return new HandledEventsAnalysis.EventContainer(HandledEventsAnalysis.EventContainerKind.Property, semanticModel.GetSymbolInfo(weecs).Symbol.Name);

e.g. In a piece of code that looks like this, the converter needs to find the symbol that SomeWithEventsFieldOrProp corresponds to:

Public Sub Eventhandler_Load(sender As Object, e As Global.System.EventArgs) Handles SomeWithEventsFieldOrProp.Load

Nearby there's a TODO that sounds related, except I think it's already been done and the comment was just accidentally left, so I'm a bit stumped here. Is it possible to provide any of the source code for those types?

[ortrails]

Sure, this is a sample file. It's from an old school ASP.NET Website project.
createMap.aspx.zip

[GrahamTheCoder]

Thanks, I've reproduced the issue, and will see if I can figure out a fix shortly

[GrahamTheCoder]

Ah apologies, I was mistaken, I haven't repro'd it yet, still looking. If I don't create the fields btnPrevious and btnStop in the same file or another one, then it breaks, but I assume you do have those defined elsewhere. Could you share the file with their definition?

I'll push a general "best effort" fix for situations where the property can't be found. But it won't be exactly correct in some scenarios (e.g. where that property gets reassigned, the events won't be moved to the new object). So I'd still definitely like to see if there is some way to find the relevant property

[ortrails]

That may be the problem. This is a file I am translating to c# as part of a process of converting website project to web application project. The web application project type has a .designer.cs with definitions for all the web controls, but since the pre-conversion files were vb (not the target c#) they were ignored and no .designer.vb files were generated. I don't know where the definitions are for the website project, probably hidden somewhere in an ASP.Net directory. Would it be worthwhile for me to try to verify this theory?

[GrahamTheCoder]

Ah yes, I see, does the converter even provide a convert project option or are you trying to do a file at a time?
If there's no convert project option, nearby files aren't taken into consideration. If that's the case, getting the files all into some kind of vbproj is the trick. They don't need to run in that form, but compiling (or the closer the better) allows the converter to grab the compilation model from the project. So just creating a library style vbproj with the appropriate references (and adding all files) may be the thing to do

[ortrails]

Yes, that'd be an interesting approach. Kind of a conversion only assembly.

…

On Wed, Jan 11, 2023 at 3:43 AM Graham ***@***.***> wrote: [image: Boxbe] <https://www.boxbe.com/overview> This message is eligible for Automatic Cleanup! ***@***.***) Add cleanup rule <https://www.boxbe.com/popup?url=https%3A%2F%2Fwww.boxbe.com%2Fcleanup%3Fkey%3DHcpPaJeqAoaujRmiUaWLIV3HBolvq%252FKh37LJu2%252B3Jsg%253D%26token%3DHW40CBcgKLjxaRpxxz6ckMLQjjL2fKP7NQ9ta2%252FnmZlpG7Nc93HpO99QDcyNLkMQleB3hW9Zn3db6FFd4fIef0TDQK0i%252BbekFGrecVNuPe4uIn48C%252F8R9tV1ccj4Vdk2pN%252FqoPZoG7rQdVR3KhNOLg%253D%253D&tc_serial=58541924214&tc_rand=1042165018&utm_source=stf&utm_medium=email&utm_campaign=ANNO_CLEANUP_ADD&utm_content=001&> | More info <http://blog.boxbe.com/general/boxbe-automatic-cleanup?tc_serial=58541924214&tc_rand=1042165018&utm_source=stf&utm_medium=email&utm_campaign=ANNO_CLEANUP_ADD&utm_content=001&> Ah yes, I see, does the converter even provide a convert project option or are you trying to do a file at a time? If there's no convert project option, nearby files aren't taken into consideration. If that's the case, getting the files all into some kind of vbproj is the trick. They don't need to run in that form, but compiling (or the closer the better) allows the converter to grab the compilation model from the project. So just creating a library style vbproj with the appropriate references may be the thing to do — Reply to this email directly, view it on GitHub <#977 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABPFMUIUYISAKOYVYZJUEMDWR2E5JANCNFSM6AAAAAATTOU2XY> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[GrahamTheCoder]

Let me know if you have success with the approach. It might be that with an example case where it worked, I could set up the converter could detect the scenario and make a best effort at something similar automatically - not sure how project dependant the setup will be

[ortrails]

@GrahamTheCoder version 9.1.2.0 works without error. Here's what I did.

1. In VS 2022 create an empty VB.NET web application.
2. Copy all the files from the old website we want to convert to the new web application folder. Overwrite and replace all. Save. Close VS 2022.
3. Open the new project in VS 2012.
4. Right click the project in Solution Explorer and select "Convert to Web Application". Save and exit VS 2012.
5. Open project again in VS 2022.
6. Right click the project in Solution Explorer and select "Convert to C#".
7. Conversion runs without error!

[GrahamTheCoder]

Great that it's worked, I've linked that from the repo wiki in case it helps others

[ortrails]

As for the ref vars, seems like if used reflection on the assembly you could possibly know if the method call needs ref or not. I think the person who wrote my project's VB code is more fond of ref parameters than the average person.

…

On Thu, Jan 12, 2023 at 5:26 PM Graham ***@***.***> wrote: [image: Boxbe] <https://www.boxbe.com/overview> This message is eligible for Automatic Cleanup! ***@***.***) Add cleanup rule <https://www.boxbe.com/popup?url=https%3A%2F%2Fwww.boxbe.com%2Fcleanup%3Fkey%3Da2OuN6aCMkd2VQzyeTX8AhELPl4c7w6B6wr%252FKq4S3Xg%253D%26token%3DQAN51yIwuqEo3whvSaI%252BCx82YQb%252BCJflRa4LBF2ve1whJ5EQA2k3JsjTQQgGMNJF2gEWx6Mj%252B%252BJSAPCLsf6dU%252BJRi8eiZ841M83ltpeoaCp%252FXnitou%252FCQhA2KtkVtiaO6KKXzhFOWd%252BuizWs1inrvQ%253D%253D&tc_serial=58549146759&tc_rand=1931252956&utm_source=stf&utm_medium=email&utm_campaign=ANNO_CLEANUP_ADD&utm_content=001&> | More info <http://blog.boxbe.com/general/boxbe-automatic-cleanup?tc_serial=58549146759&tc_rand=1931252956&utm_source=stf&utm_medium=email&utm_campaign=ANNO_CLEANUP_ADD&utm_content=001&> Great that it's worked, I've linked that from the repo wiki in case it helps others — Reply to this email directly, view it on GitHub <#977 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABPFMUKZULV75QMZKECCBNTWSCOIVANCNFSM6AAAAAATTOU2XY> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[GrahamTheCoder]

Sorry I just realised I missed this reply. I'm afraid I've lost track of what issue you're talking about with ref vars it doesn't seem to be mentioned in this thread and the only ByRef in your example (on the ShowPage method) seems to convert fine.
Would you mind opening a separate issue with a repro for any issue you're having with ref parameters if there isn't already one?
Thanks!