0

当我运行这个函数时，我得到一个对我来说没有意义的神秘错误。我不知道我正在对一个空值表达式运行一个方法。我突然想到，这要么是范围问题，要么是未设置值。但是，我无法弄清楚并将其发布给社区：

You cannot call a method on a null-valued expression.
At C:\Users\Administrator\Desktop\DCB Settings Modification\DCBxPowershell.ps1:747 char:21
+                 If ($resetAdapter -eq $FAIL_RESULT){
+                     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull
You cannot call a method on a null-valued expression.
At C:\Users\Administrator\Desktop\DCB Settings Modification\DCBxPowershell.ps1:760 char:17
+             If ($resetAdapter -eq $FAIL_RESULT){
+                 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo          : InvalidOperation: (:) [], RuntimeException
+ FullyQualifiedErrorId : InvokeMethodOnNull**

$FAIL_RESULT = 0
$PASS_RESULT = 1

Function Use-Menu
{ 
    param($DCBmenuItems, $modificationCatagoryChoosen)

    ## Function Menu-Choose --## Holds choosen Network Interface Index to work with            
    $networkIndex = Menu-Choose $strippedNetworkIndex $networkChooseTitle
    #$networkIndex[0]  ### Debug -
    $resetAdapter = $FAIL_RESULT

    Start-Sleep -s .7

    If ($result = $PASS_RESULT) {
    ## Find Current Config in order to display it to user
        $dcbConfig = Find-Config $networkIndex
    }

    #The following 'DO WHILEs' are for the "Go back to previous Menu" functionality.
    Do {
        Do {

            ## Function Menu-Choose --## Let user choose which catagory of modification to perform
            $modificationCatagoryChoosen = Menu-Choose $DCBmenuItems $DCBMenuTitle $networkIndex -scope global
            If (($DCBmenuItems.count - 1) -eq $modificationCatagoryChoosen) {
                $resetAdapter = $PASS_RESULT
            }

            # These If Then statements allow reset of adapter without changing settings
            If ($resetAdapter -eq $FAIL_RESULT){
                $DCBmenuItems2 = $xmlDCBoptions.MenuItems.MenuOptions[$modificationCatagoryChoosen].Option
                $DCBMenuTitle2 = $xmlDCBoptions.MenuItems.MenuOptions[$modificationCatagoryChoosen].Name

                Start-Sleep -s .7

                ## Function Menu-Choose --## Let user choose which modification to perform
                $modificationChoosen = Menu-Choose $DCBmenuItems2 $DCBMenuTitle2 $networkIndex
            }

        } While (($modificationChoosen -eq $DCBmenuItems2.GetUpperBound(0)) -and ($resetAdapter -eq $FAIL_RESULT))

        # These If Then statements allow reset of adapter without changing settings
        If ($resetAdapter -eq $FAIL_RESULT){ 
            ## Changes the options to choose on Menu-Choose to last chosen catagory
            $DCBmenuItems3 = $xmlDCBoptions.MenuItems.MenuOptions[$modificationCatagoryChoosen].SubMenu[$modificationChoosen].Option
            $DCBMenuTitle3 = $xmlDCBoptions.MenuItems.MenuOptions[$modificationCatagoryChoosen].SubMenu[$modificationChoosen].Name

            Start-Sleep -s .7

            ## Function Menu-Choose --## Let user choose how to modify DCB setting
            $modificationOptionChoosen = Menu-Choose $DCBmenuItems3 $DCBMenuTitle3 $networkIndex
        }
    } While (($modificationOptionChoosen -eq $DCBmenuItems3.GetUpperBound(0)) -and ($resetAdapter -eq $FAIL_RESULT)) 

    # These If Then statements allow reset of adapter without changing settings
    If ($resetAdapter -eq $FAIL_RESULT){
        Start-Sleep -s .7

         ## Function Set-RegistryValues --## Records modified DCB setting to registry
        Set-RegistryValues $xmlDCBregEdits $modificationCatagoryChoosen $modificationChoosen $modificationOptionChoosen
    }

Return $networkIndex
4

3 回答 3

1

似乎从最初的两个 if-then 语句更改为在我的初始 if-then 语句之后插入中断并在第二个 Do-Loop 上添加一个相同的语句解决了我遇到的问题。我这样做的原因是，在下一层菜单然后返回顶层后，我注意到选择重置适配器时错误不存在。

侧边栏：我没有解释我在这里列出的函数是一个遍历 $DCBmenuItems 的菜单，尽管这从代码中可能很明显。

我认为$resetAdapter由于某种原因没有正确设置。我不是 100% 确定为什么这解决了我的问题以及为什么其他代码会抛出错误。这是修改后的代码：

$FAIL_RESULT = 0
$PASS_RESULT = 1

Function Use-Menu
{ 
    param($DCBmenuItems, $modificationCatagoryChoosen)

    ## Function Menu-Choose --## Holds choosen Network Interface Index to work with            
    $networkIndex = Menu-Choose $strippedNetworkIndex $networkChooseTitle
    #$networkIndex[0]  ### Debug -

    $resetAdapter = $FAIL_RESULT
    $modificationCatagoryChoosen = $null
    $modificationChoosen = $null
    $modificationOptionChoosen = $null
    $DCBmenuItems2 = $null
    $DCBMenuTitle2 = $null
    $DCBmenuItems3 = $null
    $DCBMenuTitle3 = $null

    Start-Sleep -s .7

    If ($result = $PASS_RESULT) {
    ## Find Current Config in order to display it to user
        $dcbConfig = Find-Config $networkIndex
    }

    #The following 'DO WHILEs' are for the "Go back to previous Menu" functionality.
    Do {
        Do {

            ## Function Menu-Choose --## Let user choose which catagory of modification to perform
            $modificationCatagoryChoosen = Menu-Choose $DCBmenuItems $DCBMenuTitle $networkIndex -scope global
            If (($DCBmenuItems.count - 1) -eq $modificationCatagoryChoosen) {
                $resetAdapter = $PASS_RESULT
                break
            }

            # These If Then statements allow reset of adapter without changing settings

            $DCBmenuItems2 = $xmlDCBoptions.MenuItems.MenuOptions[$modificationCatagoryChoosen].Option
            $DCBMenuTitle2 = $xmlDCBoptions.MenuItems.MenuOptions[$modificationCatagoryChoosen].Name

            Start-Sleep -s .7

            ## Function Menu-Choose --## Let user choose which modification to perform
            $modificationChoosen = Menu-Choose $DCBmenuItems2 $DCBMenuTitle2 $networkIndex


        } While (($modificationChoosen -eq $DCBmenuItems2.GetUpperBound(0)) -and ($resetAdapter -eq $FAIL_RESULT))

        If (($DCBmenuItems.count - 1) -eq $modificationCatagoryChoosen) {
                break
        }
        # These If Then statements allow reset of adapter without changing settings

        ## Changes the options to choose on Menu-Choose to last chosen catagory
        $DCBmenuItems3 = $xmlDCBoptions.MenuItems.MenuOptions[$modificationCatagoryChoosen].SubMenu[$modificationChoosen].Option
        $DCBMenuTitle3 = $xmlDCBoptions.MenuItems.MenuOptions[$modificationCatagoryChoosen].SubMenu[$modificationChoosen].Name

        Start-Sleep -s .7

        ## Function Menu-Choose --## Let user choose how to modify DCB setting
        $modificationOptionChoosen = Menu-Choose $DCBmenuItems3 $DCBMenuTitle3 $networkIndex

    } While (($modificationOptionChoosen -eq $DCBmenuItems3.GetUpperBound(0)) -and ($resetAdapter -eq $FAIL_RESULT)) 

    # These If Then statements allow reset of adapter without changing settings
    If ($resetAdapter -eq $FAIL_RESULT){
        Start-Sleep -s .7

         ## Function Set-RegistryValues --## Records modified DCB setting to registry
        Set-RegistryValues $xmlDCBregEdits $modificationCatagoryChoosen $modificationChoosen $modificationOptionChoosen
    }

Return $networkIndex

}

于 2012-09-10T22:41:34.533 回答
0

此错误的位置似乎不正确。我看不到 PowerShell 如何在这种if ()情况下得到这种类型的错误。但是，此行可能会导致错误：

$DCBmenuItems3.GetUpperBound(0)

添加检查以确保$DCBmenuItems3不为空。此外，在调试问题时（或者只是作为一种常规做法），我将其放在Set-StrictMode -version latest脚本的顶部。

于 2012-09-07T22:38:45.540 回答
0 
FAIL_RESULT = 0
PASS_RESULT = 1

错字？

$FAIL_RESULT = 0
$PASS_RESULT = 1
于 2012-09-08T05:16:04.947 回答