Sunday, November 8, 2020

[.NET Core] 400 Bad Request / 'MS-ASPNETCORE-TOKEN' does not match the expected pairing token

At this time, I am testing an old code build by .NET Core 2.0, when I tring to send request to the service, I always got 400 Bad Request, but I can know the service got request because I am running debug mode, it shows request coming and exception happend.

Since I can't find out the error just by 400 bad request, I open "Application Insights Search" in Visual Studio and found this error.

After some digging on stackoverflow, I found the error cause by a old version bug.

This question "Cannot debug in Visual Studio after changing the port number?" 's answer has good explain about this error.

You are getting this error message because Kestrel expected to run behind IIS, and received a direct request. And it noticed that because IIS was not there to inject the MS-ASPNETCORE-TOKEN header. --Gerardo Grignoli

Here have some options to solve the problem:

  1. Call UseUrls() before UseIISIntegration() 
  2. Use Kestrel to debug, not IIS Express 
  3. Upgrade the framework

That's all,

Sunday, November 1, 2020

[.NET core] Localization with Enumeration

In .NET core, doing i18n is more easy than .NET Framework in my opinions, just give appropriate setting, then you can easily assign i18n string to anyplace you want.

Let's see how it work.

1.Add resource file 

Usually I will put my resource file in [Resources] folder, remember put cultureInfo name on resx file like this.

2.Setup Startup.cs

Add following code (depending how many language you support) into your IServiceCollection
//set Support Cultures and default
services.Configure(options =>
    var supportedCultures = new[]{
        new CultureInfo("en-US"),
        new CultureInfo("zh-TW"),
        new CultureInfo("ja-JP")
    options.DefaultRequestCulture = new RequestCulture("en-US");
    options.SupportedCultures = supportedCultures;
    options.SupportedUICultures = supportedCultures;
//set resource path
services.AddLocalization(options => options.ResourcesPath = "Resources");

Make sure your ResourcesPath set to right path.

3.DI Localizer

Since we are using .NET Core, so we need to DI our Localizer before we using it, for example if you are use it on a controller.
private readonly IStringLocalizer _localizer;
public YourController(IStringLocalizerFactory factory)
   _localizer = factory.Create("Message", System.Reflection.Assembly.GetExecutingAssembly().GetName().Name);

The "Message" is my resource name, you can DI multi Localizer if you have not only one resource group.


Here is the content of my resource, the usage for Localizer is easy, just use it like a dictionary.
var str = _localizer["Cool"];

If you wanna get a localization string for enum, it was easy too, for example your enum called "WeatherSummary".
var str = _localizer[WeatherSummary.Cool.ToString()];

It was very simple, don't need add custom thing like LocalizedDescriptionAttribute for enum i18n in .NET Framework.

You can check my demo code on github .NET-Core-Localization-and-Enum

Hope you enjoy it.