base64string

[he852100]

#Conversion error when the input and output are encoded differently
$str=".d_'+♂¢£"
$in='Unicode'
$to='utf8'
$en=[Convert]::ToBase64String([System.Text.Encoding]::$in.GetBytes($str))
$de=[System.Text.Encoding]::$to.GetString([System.Convert]::FromBase64String($en))
$en;$de

$uri='https://github.com/stadub/PowershellScripts/issues/22'
$r=irm $uri|select-string -Pattern '(?<=gid=")[^"]+' -AllMatches
$r.matches.value
$r.matches.value|%{$_|ConvertFrom-Base64String}

The common encoding in the network is utf8.

Need to use utf8,Or join the conversion option。