DVM DVM - 3 months ago 10
ASP.NET (C#) Question

Unable to translate bytes [FC] at index 35 from specified code page to Unicode

I'm trying to send an object like this to my REST API(built with asp net core)

{
"firstName":"tersü",
"lastName":"asda"
}


And this is how the headers form SoapUI look:

Accept-Encoding: gzip,deflate
Content-Type: application/json:charset=UTF-16
Host: localhost:4004
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.1.1 (java 1.5)


However, my
actionContext.ModelState
is always invalid because it can not work with the umlaute. The exception is the following:


Unable to translate bytes [FC] at index 35 from specified code page to
Unicode


If it's any help, the method signature looks like this:

[ValidateUserData]
public async Task<IActionResult> Update(string userId, [FromBody] UpdateUserRequest updateRequest)


Basically the code never goes over

if (!actionContext.ModelState.IsValid)
{
actionContext.Result = new BadRequestObjectResult(actionContext.ModelState);
}


inside the
[ValidateUserData]
attribute

What am I missing here?

Jcl Jcl
Answer

You are sending your string encoded in utf-16, but telling (in the Content-Type header's charset) it is utf-8.

The bytes for tersü in utf-8 are:

74,65,72,73,C3,BC

However tersü (in utf-16) contains the bytes (notice the FC there):

74,0,65,0,72,0,73,0,FC,0

(Check it in this fiddle)

So it just can't understand it. So either convert your string to utf-8 in your client before sending it, or set the Content-Type charset to utf-16 .

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