PowerShell and Google Protocol Buffer technology

manpreet Best Answer 3 years ago

I need to use PowerShell for Google Protocol Buffer usage. A language-specific converter has not been found and protobuf-net (C#) was used to generate .cs code and later a .dll file.

All found approaches involved New-Object construction, but public static class Serializer is defined in protobuf-net.dll, therefore an object (class instance) cannot be created -> New-Object : Constructor not found. Cannot find an appropriate constructor for type ProtoBuf.Serializer.

$memory_stream = New-Object System.IO.MemoryStream
#######
$obj = new-object ControlInterface.EnableGate
$obj.GateId = 2
$obj.Day = 7
#######
$method = [ProtoBuf.Serializer]
$Serialize = $method.GetMethods() | Where-Object {
                                 $_.Name -eq "Serialize" -and
                                 $_.MetadataToken -eq "110665038"
                                  }
$massive = @($memory_stream,$obj)
$closedMethod = $Serialize.MakeGenericMethod([ControlInterface.EnableGate])
$closedMethod.Invoke($method,$massive)

Current error is the following: Exception calling "Invoke" with "2" argument(s): "Object of type 'System.Management.Automation.PSObject' cannot be converted to type 'System.IO.Stream'."

Is it possible to avoid C# additional code usage and use only PowerShell means to overcome the issue?

manpreet 3 years ago

It's due to PowerShell casting newly created objects into a dynamic PSObject type, rather than the actual .NET type.

All you have to do is apply a cast to the object variable declaration, and your woes go away. (took me ages to find out)

To fix your example:

[IO.MemoryStream] $memory_stream = New-Object IO.MemoryStream
#######
[ControlInterface.EnableGate] $obj = new-object ControlInterface.EnableGate
$obj.GateId = 2
$obj.Day = 7
#######
$method = [ProtoBuf.Serializer]
$Serialize = $method.GetMethods() | Where-Object {
                                 $_.Name -eq "Serialize" -and
                                 $_.MetadataToken -eq "110665038"
                                  }
$massive = @($memory_stream,$obj)
$closedMethod = $Serialize.MakeGenericMethod([ControlInterface.EnableGate])
$closedMethod.Invoke($method,$massive)