Foreach 循环在 PowerShell 中不起作用

Question

我正在寻找有关 Powershell 中 foreach 循环的帮助。所以目标是根据用户请求的数量在 PowerShell 中创建新文件，因此如果用户请求创建 4 个相同的文件，它应该在请求的文件夹中创建四个文件。我似乎无法弄清楚为什么我的 foreach 循环没有制作多个文件。它每次只制作一个文件。我附上了部分代码。

$FileName = Read-Host "Enter a file name"
$FilePath = Read-Host "Enter a file path"
$FileNumber = Read-Host "How many files need to be created?"
$num = 1

if ($FileName -gt 0) { 

    foreach($num in 4) {
    New-Item -Path $FilePath -Name $filepath
    #Write-Host $number $FileNumber
    }

}

Answer 1

$FileName 是字符串，所以虽然 If($FileName -gt 0) 会返回 true，但这不是一个好习惯。

数字 4 中也没有任何内容。In 的右侧应该是一个对象集合，它在脚本之前的任何地方都没有创建。然后你有一个错字，你为 name 和 path 参数指定了 $FileName。无论如何，我认为您正在寻找这样的东西：

$FileName = Read-Host "Enter a file name"
$FilePath = Read-Host "Enter a file path"
$FileNumber = Read-Host "How many files need to be created?"
$num = 1

if ($FileName) { 
$num..$FileNumber |
    ForEach-Object{
        $NewFile = $FileName + "_" + $_
        New-Item -Path $FilePath -Name $NewFile -ItemType File
    }
}

if 逻辑适用于您的目的。然后，我将向 ForEach-Object cmdlet 的管道发送一系列数字。注意：这与您使用的 ForEach 关键字不同。无论如何，将数字连接起来，在本例中为 $_ 与先前输入的基本文件名，然后继续创建项目。

希望有帮助，请告诉我...

Answer 2

详细说明 Lee_Dailey 所说的内容，我编辑了您的代码。见我在代码内嵌的 cmets 中的注释。

$FileName = Read-Host "Enter a file name"
$FilePath = Read-Host "Enter a file path"
$FileNumber = Read-Host "How many files need to be created?"
# this next line shouldn't be needed here so I commented it out
# $num = 1

# You don't need "-gt 0".  Just use "if ($FileName)". which basically means:
# "if there is a value for $Filename then execute the block"
if ($FileName) {         
    # "foreach" really isn't the right approach here
    # use a for loop instead.  This one means:
    # start counting at $i (which is 1), if $i is less than or
    # equal to $FileNumber then execute the code block
    # and then increment $i at the end, making $i = 2
    # on the second trip through the loop
    for ($i=1; $i -le $FileNumber; $i++){
        # if you are making multiple files you can't give them all the
        # same name.  So you need to add a number at the end of each file
        # you create.  In this case $i
        $thisFileName = "$FileName" + "$i"
        New-Item -Path $FilePath -Name $thisFileName
        #Write-Host $number $FileNumber
    }

}