powershell - 如何在字符串中转义变量，PowerShell

Question

在我的代码中，我尝试将命令保留在字符串中。然后将其作为参数传递给Invoke-Expression。但是变量之前被评估

$command = "Get-Process | Where-Object { $_.Id -lt 1 }"
Invoke-Expression $command

我试过了: $$， \$ ...

Answer 1

您要查找的转义序列字符是反引号(`)!
从 about_Quoting_Rules help topic:

To prevent the substitution of a variable value in a double-quoted string, use the backtick character (`)(ASCII 96), which is the PowerShell escape character.

"This string contains a `$dollar sign that won't be expanded"

In my code, I try to keep a command in a string; to then pass it as a parameter to Invoke-Expression

作为一般的经验法则， 不这样做-您最终将控制权在脚本或函数中执行的代码交给了调用用户。
在您的示例中，只需直接执行代码就足够了:

Get-Process | Where-Object { $_.Id -lt 1 }

如果您有特定的用例，那么如果没有 Invoke-Expression，您将无法解决重写问题，请使用它来更新问题:)