如果我在PowerShell中发出以下命令，我会返回很多行。

PS C:\Users\benh> get-command

CommandType     Name                               ModuleName                         Definition
-----------     ----                               ----------                         ----------
Cmdlet          Get-Variable                       Microsoft.PowerShell.Utility       Get-Variable...
Cmdlet          Get-WebAppDomain                   WebAdministration                  Get-WebAppDomain...
Cmdlet          Get-WebApplication                 WebAdministration                  Get-WebApplication...
Cmdlet          Get-WebAppPoolState                WebAdministration                  Get-WebAppPoolState...
...
Cmdlet          Get-WinEvent                       Microsoft.PowerShell.Diagnostics   Get-WinEvent...
Cmdlet          Get-WmiObject                      Microsoft.PowerShell.Management    Get-WmiObject...
Cmdlet          Get-WSManCredSSP                   Microsoft.WSMan.Management         Get-WSManCredSSP...
Cmdlet          Get-WSManInstance                  Microsoft.WSMan.Management         Get-WSManInstance...
Cmdlet          Group-Object                       Microsoft.PowerShell.Utility       Group-Object...
Cmdlet          Import-Alias                       Microsoft.PowerShell.Utility       Import-Alias...
Cmdlet          Import-Clixml                      Microsoft.PowerShell.Utility       Import-Clixml...
Cmdlet          Import-Counter                     Microsoft.PowerShell.Diagnostics   Import-Counter...
Cmdlet          Import-Csv                         Microsoft.PowerShell.Utility       Import-Csv...
Cmdlet          Import-LocalizedData               Microsoft.PowerShell.Utility       Import-LocalizedData...
Cmdlet          Import-Module                      Microsoft.PowerShell.Core          ...

我 * 想要 * 做的是获取Get-Command返回的所有不同的ModuleName。我如何使用PowerShell来实现这一点？
在伪C#中：

PowerShell.Exec("Get-Command").Select(a=> a.ModuleName).Distinct();