json - 如何在PowerShell中将HashTable正确转换为JSON？

Question

我正在使用PowerShell将POST请求发送到REST API。请求的主体如下所示:

{
  "title": "game result",
  "attachments": [{
      "image_url": "http://contoso/",
      "title": "good work!"
    },
    {
      "fields": [{
          "title": "score",
          "value": "100"
        },
        {
          "title": "bonus",
          "value": "50"
        }
      ]
    }
  ]
}

现在，以下PowerShell脚本产生错误的输出:

$fields = @(@{title='score'; value='100'},@{title='bonus'; value='10'})
$fieldsWrap = @{fields=$fields}
#$fieldsWrap | ConvertTo-Json
$attachments = @(@{title='good work!';image_url='http://contoso'},$fieldsWrap)
$body = @{title='game results';attachments=$attachments}
$json = $body | ConvertTo-Json
$json 

第3行(如果未注释)产生正确的输出，但是第7行产生:

{
  "attachments": [{
      "image_url": "http://contoso",
      "title": "good work!"
    },
    {
      "fields": "System.Collections.Hashtable System.Collections.Hashtable"
    }
  ],
  "title": "game result"
}

显然，它写出了HashTable的类型名称，这是我假设的默认ToString()实现。
如何获得正确的输出？

Answer 1

ConvertTo-Json cmdlet具有-depth参数:

Specifies how many levels of contained objects are included in the JSON representation. The default value is 2.

因此，您必须增加它:

$body | ConvertTo-Json -Depth 4