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Question

作为更大脚本的一部分，我已经实现了下面详述的 switch。目的是当脚本执行时，用户可以选择

在屏幕上输入要迁移的用户，或者
从文件导入。

如果从文件导入选项是 selected - 我想测试文件是否存在 - 如果不存在，我想退出并返回开关标签 :choose。但是，当我 select 从文件选项导入并提供不存在的路径时，脚本会继续并且不会中断或 return 到标签。我哪里错了？

$chooseInputMethod = @"
This script migrates one or more user accounts between two trusted domains in a forest e.g. from domain1 to domain2 (or vice versa)

Select method to specify user(s) to migrate:

1. Enter name(s) on-screen (default)
2. Import name(s) from file

Enter selection number
"@

$choosePath = @"
Enter path to file..

Notes

  - Filename: 
    If file is located in script directory ($pwd) you can enter the filename without a path e.g. users.txt

  - No quotation marks: 
    DO NOT put any quotes around the path even if it contains spaces e.g. e:\temp\new folder\users.txt

Enter path or filename
"@

$enterUsernames = @"
Enter username(s) seperate each with a comma e.g. test1 or test1,test2,test3`n`nEnter name(s)
"@

cls
:choose switch (Read-Host $chooseInputMethod) {
    1 { cls; $usersFromScreen = Read-Host $enterUsernames }
    2 {
        cls;
        $usersFromFile = Read-Host $choosePath;
        if (-not (Test-Path $usersFromFile -PathType Leaf)) {
            break choose
        }
    }
    default { cls; $usersFromScreen = Read-Host $enterUsernames }
}

Write-Host "hello"

Answer 1

来自documentation for break：

In PowerShell, only loop keywords, such as Foreach, For, and While can have a label.

因此，switch，即使它具有循环功能，在这种情况下也不被视为循环。

但是，在这种情况下，我不明白为什么 break 没有标签是不够的。

Answer 2

中断开关将退出它。只有一个循环（开关，适用于数组），因此普通中断和中断开关之间没有区别。您似乎希望另一个循环内的开关重复它。

# only runs once
:outer while (1) {
  'outer'
  while (1) {
    'inner'
    break outer
  }
}


outer
inner

带有标签和循环的切换演示。文档并不完美。

# only runs once
:outer switch (1..10) {
  default {
    'outer'
    foreach ($i in 1..10) {
      'inner'
      break outer
    }
  }
}


outer
inner

另一个开关演示。

switch (1..4) {
  { $_ % 2 } { "$_ is odd" }
  default    { "$_ is even" } 
}

1 is odd
2 is even
3 is odd
4 is even

Powershell 开关中断标签未被执行

Powershell Switch Break Label not being executed

powershell

break