Element does not match nay field or property of Class – MongoDb and .net core

Hey everyone,

I ran into the following error today while searching MongoDb for an object:

Element ‘Tags’ does not match any field or property of class X.

The issue was that there were extra fields on the returned document that were not specified on the mapping target object. A bit of Googling revealed that there is a provided attribute that allows you to ignore all extra fields.

Simply add [BsonIgnoreExtraElements] to any relevant model definitions.

Thanks to this stackoverflow post for the lead: https://stackoverflow.com/a/23448987/522859

.Net Core Web Api Returning Binary File with No Headers Instead of Expected Response

Hey everyone,

A small issue I’ve run into while setting up a .net core web api microservice that also utilises a number of gRPC services. Symptoms were as follows:

Response Read via Fiddler
– HTTP/1.0 200 This buggy server did not return headers
– Value was binary and unable to be read

Server logs

03:59:23 DBG] Connection id “0HM01U963EUAR” accepted.
[03:59:23 DBG] Connection id “0HM01U963EUAR” started.
[03:59:23 DBG] Connection id “0HM01U963EUAR”: HTTP/2 connection error.
Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2.Http2ConnectionErrorException: HTTP/2 connection error (PROTOCOL_ERROR): Invalid HTTP/2 connection preface.
at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2.Http2Connection.ParsePreface(ReadOnlySequence`1& buffer, SequencePosition& consumed, SequencePosition& examined)
at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2.Http2Connection.TryReadPrefaceAsync()
at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http2.Http2Connection.ProcessRequestsAsync[TContext](IHttpApplication`1 application)
[03:59:23 DBG] Connection id “0HM01U963EUAR” is closed. The last processed stream ID was 0.
[03:59:23 VRB] Connection id “0HM01U963EUAR” sending GOAWAY frame for stream ID 0 with length 8 and flags 0x0
[03:59:23 DBG] Connection id “0HM01U963EUAR” stopped.
[03:59:23 DBG] Connection id “0HM01U963EUAR” sending FIN because: “The Socket transport’s send loop completed gracefully.”

The issue turned out to be that in appSettings.json the default kestrel endpoint had been set to utilise http2. Removing this immediately resolved the issue. It may also be worth double checking your launch settings, startup.cs and program.cs to ensure that nothing’s been overridden.

I expect that any similar routing issues would result in similar symptoms so hopefully this post will be able to save a few people a bit time!

Cheers,
Chris

Unable to find the target operating system for the project

Hi everyone,

I ran into the following error today after updating visual studio 2019 to version 16.6:

unable to find the target operating system for the project

I tried a fair few things to get this going again and I’m assuming they’re not all necessary, but I’ll list them just in case:
– Clean solution
– Close visual studio
– Delete .vs folder
– Ensure that docker-compose is set as startup project
– Edit each project’s .csproj file and ensure that the DockerDefaultTargetOS value is set: Linux
– Edit docker-compose.dcproj and ensure that DocketTargetOS is set
– Restart computer

If you’re able to narrow it down at all I’d be interested in hearing what the actual cause is!

Cheers,
Chris

OpenXml Validation Spreadsheet Value Between Two Numbers – C#

Hi everyone,

Just a quick post on how to validate a numeric cell to ensure that the value is between two numbers when using OpenXml:

// Restrict min and max values
var dataValidations = new DocumentFormat.OpenXml.Spreadsheet.DataValidations { Count = 0 };
DocumentFormat.OpenXml.Spreadsheet.DataValidation dataValidation;
dataValidation = new DocumentFormat.OpenXml.Spreadsheet.DataValidation {
Type = DataValidationValues.Decimal,
AllowBlank = false,
SequenceOfReferences = new ListValue() { InnerText = $”{columnName}2:{columnName}1048576″ },
Operator = DataValidationOperatorValues.Between,
Formula1 = new Formula1 { Text = “10 “},
Formula2 = new Formula2 { Text = “20 “},
};
dataValidations.Append(dataValidation);
dataValidations.Count++;
worksheetPart.Worksheet.Append(dataValidations);

The snippet above will ensure that any values are between 10 and 20. I didn’t come across any examples for this while searching, so hopefully this will be able to help someone else out!

Thanks,
Chris

“protobuf” visual studio a namespace cannot directly contain members such as fields or methods

Hi everyone,

I ran into the following intellisense error while adding a new proto file:

“protobuf” visual studio a namespace cannot directly contain members such as fields or methods

This was one of many errors that were shown and appeared to be an issue with Intellisense mistaking the file for a normal class definition. The following appears to have fixed it:

1) Right click on the file and select “exclude from project”
2) Clean the solution and rebuild
3) Re-include the file in the project (you may have to toggle ‘Show All Files’ at the top of solution explorer to see the excluded item).

Cheers,
Chris

Docker – Severity Code Description Project File Line Suppression State Error DT1001 Service service has neither an image nor a build context specified. At least one must be provided. docker-compose C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Sdks\Microsoft.Docker.Sdk\build\Microsoft.VisualStudio.Docker.Compose.targets 204

Hi everyone,

I ran into the following error while using docker compose and visual studio:

Severity Code Description Project File Line Suppression State
Error DT1001 Service has neither an image nor a build context specified. At least one must be provided. docker-compose C:\Program Files (x86)\Microsoft Visual Studio\2019\Community\MSBuild\Sdks\Microsoft.Docker.Sdk\build\Microsoft.VisualStudio.Docker.Compose.targets 204

It took a bit of poking around to find as the error seemed a bit ambiguous, but luckily this turned out to be a simple mistake on my part. I’d renamed my service from “servicename” to “service_name” in docker-compose.yml. Unfortunately, I hadn’t noticed the visual studio had automatically added an entry to docker-compose.override.yml. Because I hadn’t updated this entry it couldn’t find an image for the non-existent service.

A simple error on my part, but hopefully it’s able to save you a bit of time!

Cheers,
Chris

Automapper protobuf datetime to timestamp c#

Hi everyone,

I ran into the following error tonight while attempting to use automapper to map a datetime field to a protobuf timestamp property:

automapper missing type map “DateTime -> Timestamp”

To fix it, add the following to your mapping profile:

CreateMap().ConvertUsing(x => x.ToTimestamp());

UPDATE:
I later hit a similar error parsing a different entity:

Type Map configuration:
Entity-> EntityDto
EntityService.Models.Entity-> EntityService.EntityDto

Destination Member:
CreatedAt

—> System.ArgumentException: Conversion from DateTime to Timestamp requires the DateTime kind to be Utc (Parameter ‘dateTime’)

Implementing the following map appears to have resolved it:

CreateMap().ConvertUsing(x => Timestamp.FromDateTime(DateTime.SpecifyKind(x, DateTimeKind.Utc)));

If you’re planning to go the other way (timestamp -> datetime) you may also need the following:

CreateMap().ConvertUsing(x => x.ToDateTime());

I’m currently using the following base class in my library:

public class BaseMappingProfile : Profile
{
public BaseMappingProfile()
{
CreateMap().ConvertUsing(x => Timestamp.FromDateTime(DateTime.SpecifyKind(x, DateTimeKind.Utc)));
CreateMap().ConvertUsing(x => x.ToDateTime());
}
}

Google didn’t seem to turn up a lot so I thought I’d post it here in case it helps someone out!