遇到异常：Synchronous operations are disallowed. Call WriteAsync or set AllowSynchronousIO to true instead

嗯，在使用 asp.net core 中遇到这么一个异常：

Synchronous operations are disallowed. Call WriteAsync or set AllowSynchronousIO to true instead

解决方法，加入配置：

public void ConfigureServices(IServiceCollection services)
{
    // If using Kestrel:
    services.Configure<KestrelServerOptions>(options =>
    {
        options.AllowSynchronousIO = true;
    });

    // If using IIS:
    services.Configure<IISServerOptions>(options =>
    {
        options.AllowSynchronousIO = true;
    });
}

转自：https://stackoverflow.com/questions/47735133/asp-net-core-synchronous-operations-are-disallowed-call-writeasync-or-set-all