Question

我正在努力展示里程碑。我在下面尝试但是收到错误，显示Method invocation failed because [System.String] does not contain a method named 'AddDays'.我在前一行中预先定义了$lastmodified并且它是12/28/2015 0:00

$predetermined=[system.datetime]$LastModified
$date= ($predetermined).AddDays(30).ToString("MM/dd/yyyy:")

$date5 = ($date).AddDays(-15).ToString("MM/dd/yyyy:")
$date4 = ($date).AddDays(-12).ToString("MM/dd/yyyy:")
$date3 = ($date).AddDays(-9).ToString("MM/dd/yyyy:")
$date2 = ($date).AddDays(-6).ToString("MM/dd/yyyy:")
$date1 = ($date).AddDays(-3).ToString("MM/dd/yyyy:")

write-host -foregroundcolor Green "$date5 Action 1"
write-host -foregroundcolor Green "$date4 Action 2"
write-host -foregroundcolor Green "$date3 Action 3"
write-host -foregroundcolor Green "$date2 Action 4"
write-host -foregroundcolor Green "$date1 Action 5"
write-host -foregroundcolor Green "$date Action 6"

我的输出应该说

12/23/2015: Action 1"
12/26/2015: Action 2"
12/19/2015: Action 3"
12/22/2015: Action 4"
12/25/2015: Action 5"
12/28/2015: Action 6"

Answer 1

错误就在你面前：方法调用失败，因为 [System.String]不包含名为＆＃39; AddDays＆＃39;

的方法

您正在尝试使用AddDays()类中的DateTime方法，但$date不是DateTime - 对象，因为您将其转换为字符串

$date= ($predetermined).AddDays(30).ToString("MM/dd/yyyy:")

如果您要使用它来创建其他变量，则需要将$date保留为DateTime - 对象。例如：

$predetermined=[system.datetime](get-date)
$date = $predetermined.AddDays(30)

$date5 = $date.AddDays(-15).ToString("MM/dd/yyyy:")
$date4 = $date.AddDays(-12).ToString("MM/dd/yyyy:")
$date3 = $date.AddDays(-9).ToString("MM/dd/yyyy:")
$date2 = $date.AddDays(-6).ToString("MM/dd/yyyy:")
$date1 = $date.AddDays(-3).ToString("MM/dd/yyyy:")
#Convert `$date` to string using specified format
$date0 = $date.ToString("MM/dd/yyyy:")

write-host -foregroundcolor Green "$date5 Action 1"
write-host -foregroundcolor Green "$date4 Action 2"
write-host -foregroundcolor Green "$date3 Action 3"
write-host -foregroundcolor Green "$date2 Action 4"
write-host -foregroundcolor Green "$date1 Action 5"
write-host -foregroundcolor Green "$date0 Action 6"

更新：排除故障的步骤..您收到的错误包含的内容仅包括消息。它还说哪条线引起了错误。

Method invocation failed because [System.String] does not contain a method named 'AddDays'.
At line:4 char:1
+ $date5 = ($date).AddDays(-15).ToString("MM/dd/yyyy:")
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [], RuntimeException
    + FullyQualifiedErrorId : MethodNotFound

它还说AddDays()不是System.String中的方法，因此我们会在AddDays()上查看您所谓的($date).AddDays(-15)...对象：

$date

这意味着ToString()是一个字符串对象。那为什么呢？这是因为它包含$date= ($predetermined).AddDays(30).ToString("MM/dd/yyyy:") - 方法的结果。

    public static string IndentedPrint(XmlDocument doc)
    {
        using (MemoryStream memoryStream = new MemoryStream())
        {
            using (XmlTextWriter xmlTextWriter = new XmlTextWriter(memoryStream, Encoding.Unicode))
            {
                xmlTextWriter.Formatting = Formatting.Indented;

                doc.WriteContentTo(xmlTextWriter);
                xmlTextWriter.Flush();
                memoryStream.Flush();

                memoryStream.Position = 0;

                using (StreamReader sr = new StreamReader(memoryStream))
                {
                    return sr.ReadToEnd();
                }
            }
        }
    }

Answer 2

在您的代码中执行以下操作：

function Get-DateFmt1
{
    param (
        [Parameter(Mandatory=$true, Position=0)]
        [DateTime] $Date
    )

    $Date.ToString("MM/dd/yyyy")
}

$LastModified = [DateTime]::Parse('12/28/2015')
# ....
$predetermined=[DateTime]$LastModified
$date = ($predetermined).AddDays(30)

$date5 = $date.AddDays(-15)
$date4 = $date.AddDays(-12)
$date3 = $date.AddDays(-9)
$date2 = $date.AddDays(-6)
$date1 = $date.AddDays(-3)

Write-Host -Foregroundcolor Green "$($date5.ToString("MM/dd/yyyy")): Action 1"
Write-Host -Foregroundcolor Green "$($date4.ToString("MM/dd/yyyy")): Action 2"
Write-Host -Foregroundcolor Green "$($date3.ToString("MM/dd/yyyy")): Action 3"
# or write a helper function if that makes sense to you
Write-Host -Foregroundcolor Green "$(Get-DateFmt1 $date2): Action 4"
Write-Host -Foregroundcolor Green "$(Get-DateFmt1 $date1): Action 5"
Write-Host -Foregroundcolor Green "$(Get-DateFmt1 $date): Action 6"

使用Write-Host减去/添加天数到预定义的日期

2 个答案: