从表单 GridView 中的选定单元格 Ping 设备会导致错误

Question

我有一个带有从 AD 填充的网格视图的表单。这个想法是从带有主机名的网格视图中选择任何单元格，然后获取每台计算机的测试连接结果并将其发送到另一个网格视图，例如：

$Computers = $datagridview1.SelectedCells.Value

$Success = Test-Connection -ComputerName $Computers -Count 1 -ErrorAction SilentlyContinue -ErrorVariable errors | Select-Object @{ Name = 'Computer'; Expression = { $_.address } }, IPv4Address,
                       @{ Name = 'Result'; Expression = { 'Success' } }
        
$Failed = $Errors.Exception.Message | Where-Object { $_ -Match "Computer '(.+?)'" } |
Select-Object @{ Name = 'Computer'; Expression = { $Matches.1 } },
              @{ Name = 'IPv4Address'; Expression = { "N/A" } },
              @{ Name = 'Result'; Expression = { 'Failed' } }   
        
$Success + $Failed | Out-GridView -Title 'Ping Status'

只要计算机返回成功的 ping，此操作就有效。但是，失败的 ping 将返回以下错误：

方法调用失败，因为 [System.Management.Automation.PSObject] 不包含名为“op_Addition”的方法。

如果我将变量声明为

$Computers = 'Computer1','Computer2','Computer3',...

，那么网格将按预期打开，并显示成功和失败的结果。

显然，问题在于变量

$Computers = $datagridview1.SelectedCells.Value

。只是不确定我需要做什么才能使其发挥作用。

Answer 1

问题很可能发生在

$Success

是单个

PSObject

时，然后它将失败并出现您所看到的错误：

$Computers = 'google.com', 'doesnotexist.xyz'

$Success = Test-Connection -ComputerName $Computers -Count 1 -ErrorAction SilentlyContinue -ErrorVariable errors |
    Select-Object @(
        @{ Name = 'Computer'; Expression = { $_.Address }}
        'IPv4Address'
        @{ Name = 'Result'; Expression = { 'Success' }})

$Failed = $Errors.TargetObject |
    Select-Object @(
        @{ Name = 'Computer'; Expression = { $_ }}
        @{ Name = 'IPv4Address'; Expression = { "N/A" }}
        @{ Name = 'Result'; Expression = { 'Failed' }})

$Success + $Failed # Method invocation failed because [System.Management.Automation.PSObject]...

解决问题的方法很简单，只要用

数组子表达式运算符

$Success

包裹

@(...)，这样即使

$Success

中没有项目也不会失败：

@($Success) + $Failed

而且，更好的方法是包裹整个表达式：

@(
    Test-Connection -ComputerName $Computers -Count 1 -ErrorAction SilentlyContinue -ErrorVariable errors |
        Select-Object @(
            @{ Name = 'Computer'; Expression = { $_.Address }}
            'IPv4Address'
            @{ Name = 'Result'; Expression = { 'Success' }})

    $Errors.TargetObject |
        Select-Object @(
            @{ Name = 'Computer'; Expression = { $_ }}
            @{ Name = 'IPv4Address'; Expression = { "N/A" }}
            @{ Name = 'Result'; Expression = { 'Failed' }})
) | Out-GridView -Title 'Ping Status'