PowerShell foreach all files and calculate each md5 value - powershell

Question

I Have a script to get all html files in a folder,i want to get all md5 values,here's the code:
$Allfiles=get-childItem("*html")
Foreavch-object($Mfile in $Allfiles)
{
$Md5=calMd5($Mfile)
If($HashQueue.contains($Mfile))
{
Continue
}
Else
{Enqueue()}
}
i Can't get the file correctly, how to foreach every file in a dir?

Answer 1

Parentheses are never used when calling a function or cmdlet in PowerShell.
You also have a typo in your foreach-object (note the v in your code).
What is calMd5 expecting as a parameter? A file name? Full path to the file? An object? Same questions for what you're putting into $HashQueue.
Assuming calMd5 can take the path to the file and that's what you're putting into $HashQueue:
$Allfiles = get-childItem -filter *html
Foreach-object($Mfile in $Allfiles)
{
$Md5 = calMd5 $Mfile.FullName
If(!$HashQueue.contains($Mfile.FullName))
{
Enqueue()
}
}

Answer 2

It's not very clear what you're trying to do, but I'm going to infer that you want something like this:
$MD5Hashes = #{}
Get-ChildItem *.html | %{
$MD5Hashes.Add($_.Name, (calMd5 Get-Content $_ | Out-String)
}
This code creates a hashtable of the MD5 hashes of the files, keyed on the filenames, assuming that the calMd5 function takes a string argument. You'd look up the MD5 hash for a file like this: $MD5Hashes.'filename'. Or if you have the filename in a variable, like this: $MD5Hashes."$filename".
A few notes:
It's superfluous to assign the results of Get-ChildItem to a variable and iterate over it with Foreach-Object. Just pipe the results to a Foreach-Object block (%{} is shorthand for Foreach-Object). Object pipelines are one of the central features of PowerShell design. You'll learn to love 'em.
Although Get-ChildItem("*html") will work, it does so indirectly and incidentally. As alroc said, you don't use parentheses to pass arguments to a PowerShell cmdlet or function (though you do use them to pass arguments to methods). In most contexts, parentheses are an expression evaluation operator. The reason this command works is that ("*html") evaluates to the string *html, which is then passed as an argument to Get-ChildItem. In this case, the parentheses are superfluous, but in many cases you'll run into trouble enclosing arguments in parentheses, unless you intend for the argument to be the result of an expression rather than the contents of the parentheses verbatim.
If $HashQueue is a queue object and you want to add the MD5 values to this queue, you'd do this:
$HashQueue.Enqueue((calMd5 Get-Content $_ | Out-String))
However, I'm presuming that's not what you want to do, because it doesn't make sense to me to enqueue the MD5 hashes onto the end of a queue that already contains FileInfo objects representing the files (implied by If($HashQueue.contains($Mfile))).
If this is not what you want to do, please clarify. See the questions in my comment, and please be as specific as possible.