Calculated properties do not throw exceptions in Powershell. What are the workaround possibilities?

问题

Apparently there is a by design quirk in Powershell that prevents exceptions that are thrown inside a Calculated Property Expression from bubbling up. All that happens is the value of the Calculated Property ends up being null.

function Get-KBValue() {
    # Some Logic here that can throw an exception
}

....

Get-ChildItem C:\Test | 
    Select-Object Name, CreationTime,  @{Name="Kbytes"; Expression={ Get-KBValue }}

If the Get-KBValue function throws an exception then the value of the Kbytes property is set to $null and the script continues.

Possible workarounds:

• Use try/catch{break} within the Expression (Suggested by @C.B.)
• Validate afterwards. Although this might be complicated by the fact that $null could be valid in some cases.
• Use a custom object instead of a calculated property. But this is not as nice.

Any thoughts?

回答1:

Use a try/cacth in expression can help you?

10..0 | SELECT @{n="Value";e={ try { 10/$_ } catch { "error: $_" }}}

来源：https://stackoverflow.com/questions/16482316/calculated-properties-do-not-throw-exceptions-in-powershell-what-are-the-workar