{"id":1392,"date":"2009-05-07T05:30:38","date_gmt":"2009-05-07T13:30:38","guid":{"rendered":"http:\/\/www.sapien.com\/blog\/2009\/05\/07\/sometimes-an-apple-is-an-orange\/"},"modified":"2009-05-07T05:30:38","modified_gmt":"2009-05-07T13:30:38","slug":"sometimes-an-apple-is-an-orange","status":"publish","type":"post","link":"https:\/\/dev.sapien.com\/blog\/2009\/05\/07\/sometimes-an-apple-is-an-orange\/","title":{"rendered":"Sometimes an Apple is an Orange"},"content":{"rendered":"

I was helping a member out in the PowerShell forum at ScriptingAnswers.com<\/a>. He was trying to create a multistring registry entry on a remote computer using the .NET registry classes. Creating registry values is really not that complicated. Here’s a short example:<\/p>\n

\n
\n
$computer=\"CHAOS\"<\/span><\/pre>\n
$regpath=\"SYSTEM\\CurrentControlSet\\Control\\Session Manager\\Environment\"<\/span><\/pre>\n
$reg = [Microsoft.Win32.RegistryKey]::OpenRemoteBaseKey('LocalMachine'<\/span>, $Computer)<\/pre>\n
$regKey= $reg.OpenSubKey($regpath,$True)<\/pre>\n
 <\/pre>\n
#create a new string value<\/span><\/pre>\n
$regKey.SetValue(\"MyTest\"<\/span>,\"Sample Value\"<\/span>,\"STRING\"<\/span>)<\/pre>\n<\/div>\n<\/div>\n
You have to open the registry key for writing using $TRUE as the second parameter. The SetValue()<\/strong> method has several overloads. I’m using one where I specify the new registry value, its data and the value kind; in this case a string. I can also create DWORD,MultiString or Expandable string values as well.<\/p>\n
Multistring implies an array, so first I thought all that was necessary would be to specify an array. But no.<\/p>\n
PS C:\\test> $regKey.SetValue(“MyMulti”,(“a”,”b”,”c”),”MULTISTRING”)
<\/font>Exception calling “SetValue” with “3” argument(s): “The type of the value object did not match the specified RegistryValueKind or the object could not be properly converted.”
At line:1 char:17
+ $regKey.SetValue <<<< (“MyMulti”,(“a”,”b”,”c”),”MULTISTRING”)
    + CategoryInfo          : NotSpecified: (:) [], MethodInvocationException
    + FullyQualifiedErrorId : DotNetMethodException<\/font><\/font> <\/p>\n
I tried creating an array first.<\/p>\n
PS C:\\test> $arr=@(“a”,”b”,”c”)
PS C:\\test> $regKey.SetValue(“MyMulti”,$a,”MULTISTRING”)<\/font> <\/p>\n
The error was the same. Then I had a thought to compare value from an existing multistring setting so I created one using REGEDIT and retrieved it in PowerShell.<\/p>\n
PS C:\\test> $sa=$regKey.GetValue(“sa”)
PS C:\\test> $sa
lucky
daisy
ginger<\/font> <\/p>\n
It looked like an array.  Tested as an array. But so did mine.<\/p>\n
PS C:\\test> $sa -is [array]
True
PS C:\\test> $arr -is [array]
True<\/font> <\/p>\n
I tried creating a new multistring registry value with $sa. To my surprise it worked!<\/p>\n
PS C:\\test> $regKey.SetValue(“MyMulti”,$sa,”MULTISTRING”)
PS C:\\test> $regkey.GetValue(“MyMulti”)
lucky
daisy
ginger<\/font> <\/p>\n
Now I was really puzzled. I had two variables that both appeared to be arrays of strings, yet one failed . Then I tried this:<\/p>\n
PS C:\\test> $sa.getType() <\/font><\/p>\n
IsPublic IsSerial Name       BaseType
——– ——– —-       ——–
True     True     String[]   System.Array <\/font><\/p>\n
PS C:\\test> $arr.GetType() <\/font><\/p>\n
IsPublic IsSerial Name       BaseType
——– ——– —-       ——–
True     True     Object[]   System.Array<\/font><\/p>\n
Did you catch the difference? The underlying system types were different. Now I knew what to do. <\/p>\n
PS C:\\test> [string[]]$arr=@(“a”,”b”,”c”)<\/font><\/p>\n
PS C:\\test> $regKey.SetValue(“MyMulti”,$arr,”MULTISTRING”)
PS C:\\test> $regKey.GetValue(“MyMulti”)
a
b
c<\/font> <\/p>\n
I specifically cast $arr to be essentially a string of nested string. The registry was expecting simple strings, not string objects. <\/p>\n
I was distracted by PowerShell’s display of my two variables. I thought I was comparing apples to apples, but one of them was actually an orange. If I was more of a developer, I might have figured this out sooner but it was a valuable lesson to not take things at face value.<\/p>\n
If you have PowerShell questions or challenges, I hope you’ll join me in the forums at ScriptingAnswers.com.<\/p>\n","protected":false},"excerpt":{"rendered":"
I was helping a member out in the PowerShell forum at ScriptingAnswers.com. He was trying to create a multistring registry entry on a remote computer using the .NET registry classes. Creating registry values is really not that complicated. Here’s a short example.<\/p>\n","protected":false},"author":3,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[25],"tags":[82,28,31,57],"class_list":["post-1392","post","type-post","status-publish","format-standard","hentry","category-windows-powershell","tag-objects","tag-powershell","tag-registry","tag-scripting"],"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/dev.sapien.com\/blog\/wp-json\/wp\/v2\/posts\/1392","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dev.sapien.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dev.sapien.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dev.sapien.com\/blog\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/dev.sapien.com\/blog\/wp-json\/wp\/v2\/comments?post=1392"}],"version-history":[{"count":0,"href":"https:\/\/dev.sapien.com\/blog\/wp-json\/wp\/v2\/posts\/1392\/revisions"}],"wp:attachment":[{"href":"https:\/\/dev.sapien.com\/blog\/wp-json\/wp\/v2\/media?parent=1392"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dev.sapien.com\/blog\/wp-json\/wp\/v2\/categories?post=1392"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dev.sapien.com\/blog\/wp-json\/wp\/v2\/tags?post=1392"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}