无法为DataGridView列填充日历会议的DayOfWeekMask属性值

我正在开发一个小型副项目，通过WinForms的DataGridView列出Outlook日历中的周期性会议。目前可正常填充主题和开始日期列，但无法将.DayOfWeekMask属性值填充到对应的DataGridView列中——尽管通过CLI能正常访问该属性。

相关代码 #

add-type -AssemblyName 'System.Windows.Forms'
Add-Type -AssemblyName 'System.Drawing'
Add-Type -AssemblyName 'PresentationFramework'

$4 = 
"BASE64 code"

$today = get-date 

$Script:selection = @()

add-type -AssemblyName "Microsoft.Office.Interop.Outlook"
$outlookFolders = "Microsoft.Office.Interop.Outlook.OlDefaultFolders" -as [type]
$outlook = New-Object -ComObject outlook.application
$namespace = $outlook.GetNamespace("MAPI")
$folder = $namespace.GetDefaultFolder($outlookFolders::olFolderCalendar)
$items = $folder.Items
$meetings = $items|?{$_.isRecurring -eq $true -and $_.Subject -notlike "*Canceled*" <#-and $_.GetRecurrencePattern().DayOfWeekMask -eq 18#>}|Select Subject, Start, @{l='Mask';e={$_.GetRecurrencePattern().DayOfWeekMask}}

$bitmap3 = New-Object System.Windows.Media.Imaging.BitmapImage
$bitmap3.BeginInit()
$bitmap3.StreamSource = [System.IO.MemoryStream][System.Convert]::FromBase64String($4)
$bitmap3.EndInit()
$bitmap3.Freeze()

$image3 = [System.Drawing.Bitmap][System.Drawing.Image]::FromStream($bitmap3.StreamSource)

$icon3 = [System.Drawing.Icon]::FromHandle($image3.GetHicon())

$main2 = New-Object System.Windows.Forms.Form
$main2.Icon = $icon3
$main2.ClientSize = '600,600'
$main2.MinimizeBox = $false
$main2.MaximizeBox = $false
$main2.Text = 'Options'  
$main2.AutoSize = $true 

$grid = New-Object System.Windows.Forms.DataGridView
$grid.Location = '5,5'
$grid.Height = 500
$grid.Width  = 390
$grid.ColumnHeadersVisible = $true
$grid.AutoSizeColumnsMode = 'AllCells'
$grid.ColumnCount = 3
$grid.columns[0].Name = 'Name'
$grid.Columns[1].Name = 'Time'
$grid.Columns[2].Name = 'Day Mask'
$grid.MultiSelect = $true
$grid.SelectionMode = 'FullRowSelect'

$meetings|%{$grid.Rows.Add($($_.Subject), $($_.Start)), $($_.Mask)}

$button = [System.Windows.Forms.Button]::new()
$button.Location = [System.Drawing.Point]::new(5,540)
$button.Size = [System.Drawing.Size]::new(100,50)
$button.Text = 'OK'
$button.Add_Click({

$grid.SelectedRows|%{
$Script:selection += [pscustomobject]@{
                           Name = $grid.Rows[$_.Index].Cells[0].Value
                           Time = $grid.Rows[$_.Index].Cells[1].Value
                           }
                    }

})

$main2.Controls.AddRange(@($grid,$button))
$main2.ShowDialog()

核心问题：行添加语法错误 #

你在向DataGridView添加行时，错误地用括号包裹了前两个参数，导致第三个参数$_.Mask没有被正确传入Add()方法：

• 错误代码：$grid.Rows.Add($($_.Subject), $($_.Start)), $($_.Mask)
  这个写法相当于把($_.Subject, $_.Start)作为第一个参数，$_.Mask作为第二个参数传入，但DataGridViewRowCollection.Add()需要的是三个独立参数。
• 修正代码：

  $meetings | ForEach-Object { $grid.Rows.Add($_.Subject, $_.Start, $_.Mask) }
  

额外优化建议 #

1. 避免重复调用GetRecurrencePattern()
   获取周期性模式对象后复用，减少COM对象调用开销：

   $meetings = $items | Where-Object {
       $_.isRecurring -eq $true -and $_.Subject -notlike "*Canceled*"
   } | Select-Object Subject, Start, @{
       Name='Mask'
       Expression={
           $recurPattern = $_.GetRecurrencePattern()
           $recurPattern.DayOfWeekMask
       }
   }
   

2. 将掩码转换为可读的星期名称
   .DayOfWeekMask返回的是位掩码枚举值（1=周日，2=周一，4=周二，8=周三，16=周四，32=周五，64=周六），可以转换为更友好的显示文本：

   $dayMapping = @{
       1 = "周日"
       2 = "周一"
       4 = "周二"
       8 = "周三"
       16 = "周四"
       32 = "周五"
       64 = "周六"
   }
   
   $meetings = $items | Where-Object {
       $_.isRecurring -eq $true -and $_.Subject -notlike "*Canceled*"
   } | Select-Object Subject, Start, @{
       Name='Mask'
       Expression={
           $recurPattern = $_.GetRecurrencePattern()
           $selectedDays = @()
           foreach ($mask in $dayMapping.Keys) {
               if ($recurPattern.DayOfWeekMask -band $mask) {
                   $selectedDays += $dayMapping[$mask]
               }
           }
           $selectedDays -join ", "
       }
   }
   

内容的提问来源于stack exchange，提问作者Nawad-sama