运行空间中的Register-ObjectEvent

Question

I have a Barcode scanning script. it opens the RS323 Port to the handheld scanner register-objects event on "DataReceived" runs an action Scriptblock to update database fields.

this all works when running normally (from mainthread) but now i would like to do the same from a runspace and return the barcode to the mainthread. this way i would not block the running thread.

$bcHandler =[runspacefactory]::CreateRunspace()

# set Single Threaded Apartment and reuse thread
$bcHandler.ApartmentState = "STA"
$bcHandler.ThreadOptions = "ReuseThread"      
# Open the runspace
$bcHandler.Open()

$psCmd = [PowerShell]::Create().AddScript({
    Param($ComPort="COM3")

    $port= new-Object System.IO.Ports.SerialPort $ComPort,9600,None,8,one

    Register-ObjectEvent -InputObject $port -EventName "DataReceived" -SourceIdentifier $port.PortName -Action {

        # start stopwatch for perforance measurements
        $StopWatch = [System.Diagnostics.Stopwatch]::StartNew()

        # Read scanner buffer
        $Result = ($port.ReadExisting() | Out-String).Trim()

        # Send beep to handheld scanner
        $port.Write([char]7,0,1)
    }
})


# Open the runspace
$psCmd.Runspace = $bcHandler
$Handler = $psCmd.BeginInvoke()

Answer 1

You can use a synchronized hash table to store the Result data, which would allow you to see the data from the parent runspace

$Global:syncHash = [hashtable]::Synchronized(@{})

$bcHandler =[runspacefactory]::CreateRunspace()

# set Single Threaded Apartment and reuse thread
$bcHandler.ApartmentState = "STA"
$bcHandler.ThreadOptions = "ReuseThread"   
# Open the runspace
$bcHandler.Open()
#Synch the HashTable between runspaces
$bcHandler.SessionStateProxy.SetVariable("syncHash", $syncHash)

$psCmd = [PowerShell]::Create().AddScript({
    Param($ComPort="COM3")

    $port= new-Object System.IO.Ports.SerialPort $ComPort,9600,None,8,one

    Register-ObjectEvent -InputObject $port -EventName "DataReceived" -SourceIdentifier $port.PortName -Action {

        # start stopwatch for perforance measurements
        $StopWatch = [System.Diagnostics.Stopwatch]::StartNew()

        # Read scanner buffer
        $syncHash.Result = ($port.ReadExisting() | Out-String).Trim()

        # Send beep to handheld scanner
        $port.Write([char]7,0,1)
    }
})


# Open the runspace
$psCmd.Runspace = $bcHandler
$Handler = $psCmd.BeginInvoke()

You can then access the result using $syncHash.Result