为什么ps1中的Write-host没有显示在控制台中？

Question

我有一个字典和一个foreach输出那个字典，都在ps1文件中，我用.\MyScript.ps1

运行

$tokenColors = @{ 
  "None" = "White";
  "Comment" = "Black";
  "Keyword" = "Black";
  "Command" = "DarkCyan";
  "Parameter" = "Black";    
  "Operator" = "Gray";    
  "String" = "Gray";    
  "Number" = "Gray";
  "Type" = "DarkGreen";
  "Variable" = "DarkGreen";
  "Member" = "DarkGreen";    
}

foreach ($token in $tokenColors.Keys) {
  Write-Host "${token}: $($tokenColors[$token])"
  Set-PSReadlineOption -TokenKind $token -ForegroundColor $($tokenColors[$token]) -BackgroundColor DarkGray
}

这不会输出任何文字。为什么？ （直接在终端中粘贴代码会产生预期的结果，但是从脚本中却没有）

PS dev:\> $PSVersionTable

Name                           Value
----                           -----
PSVersion                      5.0.10586.122
PSCompatibleVersions           {1.0, 2.0, 3.0, 4.0...}
BuildVersion                   10.0.10586.122
CLRVersion                     4.0.30319.42000
WSManStackVersion              3.0
PSRemotingProtocolVersion      2.3
SerializationVersion           1.1.0.1

PS dev:\> (Get-WmiObject win32_operatingsystem).version
10.0.10586