如何将PowerShell数组合并到PSCustomObject生成正确JSON结构？

我正在构建一个生成API调用JSON payload的函数，需要在主成员contact下添加数组类型的子成员fieldValues。试了两种写法都没得到正确结构：第一种生成的数组内容异常，第二种的fieldValues不在contact成员内。以下是错误示例代码和预期的正确JSON格式，求指出问题所在。

错误示例1代码 #

[PSCustomObject] $contactMain = @{}
[PSCustomObject] $contactDetail_Native = @{}
[array] $contactDetail_Custom = @()

$contactDetail_Custom = `
    [PSCustomObject]@{
        field = '1'
        value = '1001'
    }

$contactDetail_Custom += $contactDetail_Custom

$contactDetail_Custom = `
    [PSCustomObject]@{
        field = '2'
        value = '1002'
    }

$contactDetail_Custom += $contactDetail_Custom

$contactDetail_Native = `
    [ordered]@{
        email     = 'brucebanner@myfakeemail.com'
        lastName  = 'Banner'
        firstName = 'Bruce'
    }

$contactDetail_Native.Add('fieldValues', $contactDetail_Custom)

$contactMain | Add-Member -MemberType NoteProperty -Name 'contact' -Value $contactDetail_Native -Force
#$contactMain | Add-Member -MemberType NoteProperty -Name 'fieldValues' -Value $contactDetail_Custom -Force

$contactMain = $contactMain | ConvertTo-Json
$contactMain

错误示例2代码 #

[PSCustomObject] $contactMain = @{}
[PSCustomObject] $contactDetail_Native = @{}
[array] $contactDetail_Custom = @()

$contactDetail_Custom = `
    [PSCustomObject]@{
        field = '1'
        value = '1001'
    }

$contactDetail_Custom += $contactDetail_Custom

$contactDetail_Custom = `
    [PSCustomObject]@{
        field = '2'
        value = '1002'
    }

$contactDetail_Custom += $contactDetail_Custom

$contactDetail_Native = `
    [ordered]@{
        email     = 'brucebanner@myfakeemail.com'
        lastName  = 'Banner'
        firstName = 'Bruce'
    }

#$contactDetail_Native.Add('fieldValues', $contactDetail_Custom)

$contactMain | Add-Member -MemberType NoteProperty -Name 'contact' -Value $contactDetail_Native -Force
$contactMain | Add-Member -MemberType NoteProperty -Name 'fieldValues' -Value $contactDetail_Custom -Force

$contactMain = $contactMain | ConvertTo-Json
$contactMain

预期正确的JSON格式 #

{"contact": {
    "firstName":  "Bruce",
    "lastName":  "Banner",
    "email":  "brucebanner@myfakeemail.com",
    "fieldValues":  [
                        {
                            "field":  "1",
                            "value":  "1001"
                        },
                        {
                            "field":  "2",
                            "value":  "1002"
                        }
                    ]
}}

问题分析与修正 #

错误示例1的核心问题 #

数组构建逻辑错误：

1. 每次执行$contactDetail_Custom = [PSCustomObject]@{...}时，会直接覆盖之前的数组变量，把它从数组变成单个对象。
2. 随后的$contactDetail_Custom += $contactDetail_Custom是将当前对象追加给自己，导致数组里是重复的同一个对象，最终得到的是两个field=2的对象，而非field=1和field=2各一个。

错误示例2的核心问题 #

结构层级错误：
你把fieldValues直接添加到了根对象contactMain上，而非contact子对象内部，导致它不在预期的层级里。

修正后的代码（两种写法） #

写法1：直接嵌套构建

# 一次性构建完整结构
$contactMain = [PSCustomObject]@{
    contact = [PSCustomObject]@{
        email     = 'brucebanner@myfakeemail.com'
        lastName  = 'Banner'
        firstName = 'Bruce'
        fieldValues = @(
            [PSCustomObject]@{
                field = '1'
                value = '1001'
            },
            [PSCustomObject]@{
                field = '2'
                value = '1002'
            }
        )
    }
}

# 转换为JSON时指定Depth，避免嵌套结构被截断
$contactMain | ConvertTo-Json -Depth 3

写法2：分步构建

# 正确初始化数组并添加两个不同对象
$contactDetail_Custom = @()
$contactDetail_Custom += [PSCustomObject]@{
    field = '1'
    value = '1001'
}
$contactDetail_Custom += [PSCustomObject]@{
    field = '2'
    value = '1002'
}

# 构建contact子对象，直接包含fieldValues
$contactDetail_Native = [ordered]@{
    email     = 'brucebanner@myfakeemail.com'
    lastName  = 'Banner'
    firstName = 'Bruce'
    fieldValues = $contactDetail_Custom
}

# 构建主对象
$contactMain = [PSCustomObject]@{
    contact = $contactDetail_Native
}

# 转换为JSON
$contactMain | ConvertTo-Json -Depth 3

关键注意点 #

• 数组构建：要么用@()一次性包裹多个对象，要么逐个追加时不要覆盖原有数组变量。
• 层级控制：确保fieldValues是contact对象的属性，而非根对象属性。
• ConvertTo-Json的-Depth参数：默认深度为2，嵌套层级超过2时必须指定足够的深度，否则会导致结构被截断。

内容的提问来源于stack exchange，提问作者James