Can't write to stream inside event

问题

I am can try to run NHTTP(simple asynchronous HTTP server written in C# for the .NET framework. You can download this dll in nuget, or view source code on github) But i am cant write my own response to client from my server, because i am can't write to OutputStream.

My powershell script:

Add-Type -Path "NHttp.dll"

$server = New-Object NHttp.HttpServer
$server.EndPoint =  new-object System.Net.IPEndPoint ([System.Net.IPAddress]::Parse("127.0.0.1"), 8080)


$RequestReceived = {

    $request = $EventArgs.Request
    $response = $EventArgs.Response

    $global:response = $response.OutputStream.CanWrite

    $writer = New-Object System.IO.StreamWriter($response.OutputStream)
    $writer.AutoFlush = $true
    $writer.WriteLine("Hello World")    


}

Register-ObjectEvent -InputObject $server -EventName RequestReceived -SourceIdentifier RequestReceived -Action $RequestReceived

$server.Start()

Always when my server receive request from client $global:response=False

An error occurring in the Event, which occurs when the server receives a request:

writeErrorStream      : True
PSMessageDetails      : 
Exception             : System.Management.Automation.MethodInvocationException: Exce
                        ption when calling the ".ctor" with "1" argument: "Stream wa
                        s not writable" ---> System.ArgumentException: Stream was no
                        t writable.
                          at System.IO.StreamWriter..ctor(Stream stream, Encoding en
                        coding, Int32 bufferSize, Boolean leaveOpen)
                          at System.IO.StreamWriter..ctor(Stream stream)
                           --- End of inner exception stack trace ---
                          at System.Management.Automation.DotNetAdapter.AuxiliaryCon
                        structorInvoke(MethodInformation methodInformation, Object[]
                         arguments, Object[] originalArguments)
                          at Microsoft.PowerShell.Commands.NewObjectCommand.CallCons
                        tructor(Type type, ConstructorInfo[] constructors, Object[] 
                        args)
TargetObject          : 
CategoryInfo          : InvalidOperation: (:) [New-Object], MethodInvocationExceptio
                        n
FullyQualifiedErrorId : ConstructorInvokedThrowException,Microsoft.PowerShell.Comman
                        ds.NewObjectCommand
ErrorDetails          : 
InvocationInfo        : System.Management.Automation.InvocationInfo
ScriptStackTrace      : at <ScriptBlock>, C:\powershell_scripts\tmp\nhttp.ps1: line 18
PipelineIterationInfo : {}

And server response clean white page and StatusCode 200 to client.

But example for C# work perfectly:

using (var server = new HttpServer())
{
    server.RequestReceived += (s, e) =>
    {
        using (var writer = new StreamWriter(e.Response.OutputStream))
        {
            writer.Write("Hello world!");
        }
    };

    server.Start();

    Process.Start(String.Format("http://{0}/", server.EndPoint));

    Console.WriteLine("Press any key to continue...");
    Console.ReadKey();
}

Such behavior within the Action block when called Event created by Register-ObjectEvent occurs to me is not the first time. I try to solve it, changing "apartment" model(STA and MTA), but it not solve the problem. If you need i am have more examples.

来源：https://stackoverflow.com/questions/33251038/cant-write-to-stream-inside-event

标签

powershell

outputstream

streamwriter

httpserver