次のファイル hostname.csv から辞書を作成しようとしています:
hostname type
LON131 gaming
LON132 gaming
LON133 research
LON134 research
以下の Powershell スクリプトを使用します。
get-content hostname.csv | ForEach-Object {
if ($dict.Keys -contains $_.type) {
$dict[$_.type]+=$_.hostname
} else {
$dict.Add($_.type,@($_.hostname))
}
}
Write-Host $dict;
しかし、次のエラーメッセージが表示され続けます。
Exception calling "Add" with "2" argument(s): "Key cannot be null.
Parameter name: key"
At fcheck.ps1:7 char:29
+ $dict.Add($_.type,@($_.hostname))
+ ~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : ArgumentNullException
Exception calling "Add" with "2" argument(s): "Key cannot be null.
Parameter name: key"
At fcheck.ps1:7 char:29
+ $dict.Add($_.type,@($_.hostname))
+ ~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : ArgumentNullException
Exception calling "Add" with "2" argument(s): "Key cannot be null.
Parameter name: key"
At fcheck.ps1:7 char:29
+ $dict.Add($_.type,@($_.hostname))
+ ~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : ArgumentNullException
Exception calling "Add" with "2" argument(s): "Key cannot be null.
Parameter name: key"
At fcheck.ps1:7 char:29
+ $dict.Add($_.type,@($_.hostname))
+ ~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : ArgumentNullException
Exception calling "Add" with "2" argument(s): "Key cannot be null.
Parameter name: key"
At fcheck.ps1:7 char:29
+ $dict.Add($_.type,@($_.hostname))
+ ~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [], MethodInvocationException
+ FullyQualifiedErrorId : ArgumentNullException
何が原因で、どうすれば解決できますか?