可以使用以下代码在启动文件中设置大小写敏感性：

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddSingleton();
        services.AddControllers(options =>
        {
            options.UseCaseInsensitiveRouting = true;
        });
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env, CaseSensitiveRouting caseSensitiveRouting)
    {
        if (caseSensitiveRouting.IsCaseSensitive)
        {
            app.Use((context, next) =>
            {
                context.Request.Path = new PathString(context.Request.Path.ToString().ToLower());
                return next();
            });
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();

        app.UseRouting();

        app.UseAuthentication();
        app.UseAuthorization();

        app.UseEndpoints(endpoints =>
        {
            endpoints.MapControllers();
        });
    }

    private class CaseSensitiveRouting
    {
        public bool IsCaseSensitive { get; }

        public CaseSensitiveRouting(IConfiguration configuration)
        {
            IsCaseSensitive = configuration.GetValue("CaseSensitiveRouting") == true;
        }
    }
}