问题
I'm getting some odd behavior from Excel's Cells.Find() method:
Variable I'm searching on:
PS > $volumename
vol_01
PS > $volumename.GetType()
IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True True String System.Object
produces no results:
PS > $sheet.Cells.Find($volumename).Row
but if I manually copy and paste the value of that variable:
PS > $volumename = "vol_01"
PS > $volumename.GetType()
IsPublic IsSerial Name BaseType
-------- -------- ---- --------
True True String System.Object
Gets the value I am expecting:
PS > $sheet.Cells.Find($volumename).Row
198
They appear to be exactly the same type in every way to me. This doesn't happen for every case. Some volume names passthrough fine while others do not. I did scrub the volume name for this post as it has a customers naming convention. It is the same format as above and the same format as the volume names that work.
回答1:
The following snippet can be used to inspect a string for hidden control characters:
PS> & { [int[]] [char[]] $Args[0] | % { '0x{0:x} [{1}]' -f $_, [char] $_ } } "vol_01`n"
0x76 [v]
0x6f [o]
0x6c [l]
0x5f [_]
0x30 [0]
0x31 [1]
0xa [
]
The first column is each character's Unicode code point ("ASCII code"), and the second column the character itself, enclosed in [...]
Note that I've added "`n" at the end of the string - a newline character (U+000A) - whose code point expressed as a hex. number is 0xa.
If, as in your case, the only unwanted part of the string is trailing whitespace, you can remove them as follows:
$volumename.TrimEnd() # trim trailing whitespace
In your case, the trailing whitespace is 0xa0, the NO-BREAK SPACE (U+00A0), which .TrimEnd() also removes, as Tom Blodget points out.
Simple function wrapper based on the above, for use with pipeline input:
filter debug-Chars { [int[]] [char[]] $_ | % { '0x{0:x} [{1}]' -f $_, [char] $_ } }
Sample use:
"vol_01`n" | debug-Chars
来源：https://stackoverflow.com/questions/52647708/unexpected-behavior-with-a-string-stored-in-a-variable-in-powershell