I use the following to create an instance of a class for storing user information during the request:
services.AddScoped<IUserSettings, UserSettings>();
Then I use middleware to set the values of the userSettings.
public async Task InvokeAsync(HttpContext context, IUserSettings userSettings, IHttpClientFactory httpClientFactory)
{
// Do some stuff here and set userSettings properties
}
The problem is when I send multiple requests in parallel, only one of them gets a non null userSettings.
Why does this happen and how can I fix it?
As of now I use httpContext.Items to store and use userSettings.
According to the document:
To use scoped services in middleware, use one of the following approaches:
- Inject the service into the middleware’s Invoke or InvokeAsync method. Using constructor injection throws a runtime exception because it forces the scoped service to behave like a singleton. The sample in the Lifetime and registration options section demonstrates the InvokeAsync approach.
- Use Factory-based middleware. Middleware registered using this approach is activated per client request (connection), which allows scoped services to be injected into the middleware’s constructor.
So I suggest you could modify your middleware to use Factory-based middleware to see if we could solve this issue.
More details, you could refer to below example:
Usersettings:
public interface IUserSettings
{
string UserId { get; set; }
string UserName { get; set; }
}
// UserSettings.cs
public class UserSettings : IUserSettings
{
public string UserId { get; set; }
public string UserName { get; set; }
}
Usersettings middleware:
public class UserSettingsMiddleware : IMiddleware
{
private readonly IUserSettings _userSettings;
public UserSettingsMiddleware(IUserSettings userSettings)
{
_userSettings = userSettings;
}
public async Task InvokeAsync(HttpContext context, RequestDelegate next)
{
_userSettings.UserId = "123";
_userSettings.UserName = "John Doe";
await next(context);
}
}
MiddlewareExtensions:
public static class MiddlewareExtensions
{
public static IApplicationBuilder UseUserSettingsMiddleware(
this IApplicationBuilder app)
=> app.UseMiddleware<UserSettingsMiddleware>();
}
Register inside the program.cs:
...
builder.Services.AddScoped<IUserSettings, UserSettings>();
builder.Services.AddTransient<UserSettingsMiddleware>();
...
app.UseUserSettingsMiddleware();
Result: