Loading a Type Library via PowerShell and scripting Windows Live Writer

Question

I'm very new to COM and Windows programming/scripting in general. What I was trying to do is scripting Windows Live Writer; according to the documentation before I can call ``` $o = New-Object -c WindowsLiveWriter.Application ``` I need to load the TLB first, so I should call the `add-type` command, unfortunately it fails: ``` PS C:\Users\NoWhereMan> add-type windowslivewriter.application Add-Type : c:\Users\NoWhereMan\AppData\Local\Temp\a7ifbimo.0.cs(1) : A namespace does not directly contain members such as fields or methods c:\Users\NoWhereMan\AppData\Local\Temp\a7ifbimo.0.cs(1) : >>> windowslivewriter.application At line:1 char:9 + add-type <<<< windowslivewriter.application + CategoryInfo : InvalidData: (c:\Users\NoWher...elds or methods:CompilerError) [Add-Type], Exception + FullyQualifiedErrorId : SOURCE_CODE_ERROR,Microsoft.PowerShell.Commands.AddTypeCommand Add-Type : Cannot add type. There were compilation errors. At line:1 char:9 + add-type <<<< windowslivewriter.applicatio…

Accepted Answer

From `help add-type`:

Adds a Microsoft .NET Framework type (a class) to a Windows PowerShell session.

but `windowslivewriter.application` is not a .NET type.

PowerShell (PSH) directly supports COM objects, you do not need to take any special steps to load the Type Library (TLB)1, just call the methods diretcly as given in the documentation for the component. E.g.:

```
$lw = New-Object -com WindowsLiveWriter.Application   
$lw.NetPost()
```

to launch the new post editor.

Summary: you do not need to load the TLB first.

Under 64bit Windows, you might need to ensure you are running a 32bit instance ("x86") of PSH to do this (depending if the Live Writer component runs in or out of process).

1 Strictly speaking, this only applies to COM types that support scripting with IDispatch, but in practice there are few that don't.

Loading a Type Library via PowerShell and scripting Windows Live Writer

Solution

Problem