发送 email 附件 - 将 CSV 文件转换为字节删除换行符

Question

我正在尝试使用 MS Graph cmdlet Send-MgUserMail发送一个 email 并包含一个 CSV 附件。

如果我这样做，效果很好，附件也很好。

样本CSV附件

"App","AppId","Date","User"
"App1","43a9087d-8551-47d5-9869-3287736ce7c3","2023/01/26","me@email.com"
"App2","f33750cd-c79b-43be-8e55-ee14d163e2b3","2024/01/26","me@email.com"

工作代码

$attachment   = "C:\Users\Me\Downloads\SampleFile.csv"
$base64string = [Convert]::ToBase64String([IO.File]::ReadAllBytes($attachment))

$params = @{
    UserId = "me@email.com"
    BodyParameter = @{
        Message = @{
            Subject = "Test Email"
            Body    = @{
                ContentType = "Html"
                Content     = "This is sample text."
            }
            ToRecipients = @(
                @{
                    EmailAddress = @{
                        Address = "toAddress@email.com"
                    }
                }
            )
            Attachments = @(
                @{
                    "@odata.type" = "#microsoft.graph.fileAttachment"
                    Name         = "SampleFile.csv"
                    ContentType  = "text/csv"
                    ContentBytes = $base64string
                }
            )
        }
        SaveToSentItems = "false"
    }
}
 
Send-MgUserMail @params

客观的

我想要的是附加 CSV，但没有实际保存的文件。 内容将来自 memory，像这样。

$output = @(
    [PSCustomObject] @{
        App = "App1"
        AppId = "43a9087d-8551-47d5-9869-3287736ce7c3"
        Date  = "2023/01/26"
        User  = "me@email.com"
    },
    [PSCustomObject] @{
        App = "App2"
        AppId = "f33750cd-c79b-43be-8e55-ee14d163e2b3"
        Date  = "2024/01/26"
        User  = "me@email.com"
    }
)

$attachment = $output | ConvertTo-Csv -NoTypeInformation

$bytes         = [System.Text.Encoding]::UTF8.GetBytes($attachment)
$base64string  = [Convert]::ToBase64String($bytes)

当我这样做时，我的问题是 CSV 内容完全在 1 行上，没有更多的换行符。

发行样品 CSV Output

"App","AppId","Date","User" "App1","43a9087d-8551-47d5-9869-3287736ce7c3","2023/01/26","me@email.com" "App2","f33750cd-c79b-43be-8e55-ee14d163e2b3","2024/01/26","me@email.com"

我怎样才能正确转换它？

Answer 1

评论中给出了答案，但要关闭它，在获取 Csv 的字节之前， ConvertTo-Csv会输出一个字符串数组并且它们没有换行符（Windows 中的 CRLF，Linux 中的 LF）需要将此数组转换为单个多行字符串，为此您可以使用Out-String ：

$attachment = $output | ConvertTo-Csv -NoTypeInformation | Out-String

或者通过换行符加入它们以保留结构：

$attachment = ($output | ConvertTo-Csv -NoTypeInformation) -join [Environment]::NewLine

此外，具有字符串类型参数的[System.Text.Encoding]::UTF8.GetBytes(...)将您的数组强制转换为字符串，当您将数组强制转换为 PowerShell 中的字符串时，它由$OFS加入（默认情况下是一个空白字符）因此，为什么在解码 base64 字符串时会得到一行由空白字符连接的原因。

---

另一种可以做到这一点的方法是为$OFS分配换行符的值：

$attachment = $output | ConvertTo-Csv -NoTypeInformation
$OFS = [System.Environment]::NewLine
$bytes         = [System.Text.Encoding]::UTF8.GetBytes($attachment)
$base64string  = [Convert]::ToBase64String($bytes)
$OFS = ' '

# Decoding should look as expected
[System.Text.Encoding]::UTF8.GetString(
    [Convert]::FromBase64String($base64string)
)