PowerCLI哈希表重复键添加报错：调用Add方法参数为2时触发异常

核心问题分析 #

• 哈希表键重复添加错误：foreach循环中若存在多个匹配tier0_path的Tier1网关，每次循环都会调用Add方法添加相同键，而哈希表不允许重复键，因此抛出异常。
• 最终判断逻辑错误：$testingHash.T1G存储的是匹配到的Tier1网关对象，并非布尔值，用它和$true比较永远不成立，导致匹配成功也输出错误结果。

修复步骤 #

1. 替换哈希表Add方法为直接赋值 #

用直接赋值替代Add方法，键存在时会覆盖值，不存在时自动添加，避免重复键报错：

$testingHash['T1G'] = $t1g
$testingHash['IST1G'] = $true

2. 修正最终判断条件 #

直接判断IST1G的布尔值，或者判断T1G是否不为null，确保逻辑正确：

If ($testingHash.IST1G) {
    Write-Output "YES!!!"
}
else {
    Write-Output "OH NO!"
}

3. 可选优化：找到匹配项后退出循环 #

如果只需要第一个符合条件的Tier1网关，添加break跳出循环，避免不必要的遍历：

If ($t1g.tier0_path -eq $t1t0connection) {
    Write-Output "t1-stretched is connected to t0-gateway-stretched"
    $testingHash['T1G'] = $t1g
    $testingHash['IST1G'] = $true
    break # 找到匹配项后终止循环
}

完整修复后的脚本 #

#I have left out the previous code where I retrieve the ID of the T0 Gateway.
#
#Verify if the T0 path is retrieved correctly
Write-Host "========================================"
Write-Host $t1t0connection
Write-Host "========================================"

#Get Tier 1 Gateways    
$resultsT1g = Invoke-WebRequest -Uri "$uri/global-manager/api/v1/global-infra/tier-1s" -Headers $header

#Parse return and create an object from the results
$t1gItems = ConvertFrom-Json -InputObject $resultsT1g.Content -Depth 10 -AsHashtable

#Find the Tier 1 Gateway and store it in the testing hashtable
foreach ($t1g in $t1gItems.results)
{
    If ($t1g.tier0_path -eq $t1t0connection)
    {
        Write-Output "t1-stretched is connected to t0-gateway-stretched"
        # 替换Add方法为直接赋值，避免键重复错误
        $testingHash['T1G'] = $t1g
        $testingHash['IST1G'] = $true
        # 可选：找到第一个匹配项后退出循环
        break
    }
}

If ($null -eq $testingHash.T1G)
{
    $testingHash['IST1G'] = $false
    Write-Error "t1-stretched is not connected to t0-gateway-stretched"
}

#Output pass/fail
# 修正判断条件，使用IST1G的布尔值判断
If ($testingHash.IST1G)
{
    Write-Output "YES!!!"
}
else {
    Write-Output "OH NO!"
}

验证说明 #

• 修复后不会再出现键重复的异常，即使存在多个匹配项；
• 最终判断逻辑会根据实际匹配结果正确输出对应信息；
• 添加break后可提升脚本执行效率，减少不必要的循环遍历。

内容的提问来源于stack exchange，提问作者I-1