arrays - 从函数返回数组列表

Question

因此，我有一个poweshell表单，您可以在其中将用户添加到列表框，同时添加到arraylist。当我尝试返回所有用户的arraylist时，它什么也不返回。

这是我的代码

#---------------------#
# Function AddUserGUI #
#---------------------#
Function AddUserGUI()
{
    $AllUsers = New-Object System.Collections.ArrayList

    #---Form    
    $Form                 = New-Object System.Windows.Forms.Form
    $Form.FormBorderStyle = "FixedSingle"
    $Form.Size            = New-Object System.Drawing.Size(295,280)
    $Form.MaximizeBox     = $False
    $Form.Text            = "Add User(s)"
    $Form.StartPosition   = "CenterScreen"
    $Form.Font            = New-Object System.Drawing.Font("Segoe UI",9,0,3,1)

    #---TexBox
    $objTextBox           = New-Object System.Windows.Forms.TextBox
    $objTextBox.Location  = New-Object System.Drawing.Size(10,10)
    $objTextBox.Size      = New-Object System.Drawing.Size(183,100)
    $objTextBox.MaxLength = 100

    #---ListBox  
    $objListBox                     = New-Object System.Windows.Forms.ListBox
    $objListBox.Location            = New-Object System.Drawing.Size(10,45)
    $objListBox.Size                = New-Object System.Drawing.Size(183,199)
    $objListBox.HorizontalScrollbar = $True  

    #---Buttons
    $Add           = New-Object System.Windows.Forms.Button
    $Add.Location  = New-Object System.Drawing.Size(205,10)
    $Add.Size      = New-Object System.Drawing.Size(75,23)
    $Add.FlatStyle = "PopUp"
    $Add.Text      = "Add"

    $Remove           = New-Object System.Windows.Forms.Button
    $Remove.Location  = New-Object System.Drawing.Size(205,45)
    $Remove.Size      = New-Object System.Drawing.Size(75,23)
    $Remove.FlatStyle = "PopUp"
    $Remove.Text      = "Remove"

    $Confirm           = New-Object System.Windows.Forms.Button
    $Confirm.Location  = New-Object System.Drawing.Size(205,220)
    $Confirm.Size      = New-Object System.Drawing.Size(75,23)
    $Confirm.FlatStyle = "PopUp"
    $Confirm.Text      = "Confirm"

    #---Buttons On-Click Actions    
    $Add_OnClick= 
    {   
        if($objTextBox.Text -ne "")
        {
            $UserChk = $true #[Bool](Get-ADObject -Filter { sAMAccountName -eq $objTextBox.Text } -Searchbase "ou=User_PFS,dc=pfs,dc=local")

            if($UserChk -eq $True)
            {
                if($objListBox.Items -contains $objTextBox.Text) {DisplayMsgBox "User already in list." "Duplicate entry" "Information" 0}

                ElseIf($objTextBox.Text -ne $NULL -and $objListBox.Items -notcontains $objTextBox.Text)
                {
                    $objListBox.Items.Add($objTextBox.Text)
                    [void]$AllUsers.Add($objTextBox.Text)
                }
            }

            ElseIf($UserChk -eq $False) {DisplayMsgBox "User not found." "Invalid User Name" "Information" 0}

            $objTextBox.Text = ""
        }
    }

    $Remove_OnClick= 
    {
        $AllUsers.Remove($objListBox.SelectedItem)
        $objListBox.Items.Remove($objListBox.SelectedItem)
    }

    $Confirm_OnClick= 
    {
        if($AllUsers.Count -eq 0)
        {
            DisplayMsgBox "Please add at least one user to the list." "No Users Found" "Information" 0
        }

        ElseIf($AllUsers.Count -gt 0)
        {
            $Form.Close()

            Return $AllUsers
        }
    }

    #---Adding Elements to the form
    $Add.add_Click($Add_OnClick)
    $Remove.add_Click($Remove_OnClick)
    $Confirm.add_Click($Confirm_OnClick)

    $Form.Controls.Add($objListBox)
    $Form.Controls.Add($objTextBox)
    $Form.Controls.Add($Add)
    $Form.Controls.Add($Remove)
    $Form.Controls.Add($Confirm)

    #---Display Form
    $Form.ShowDialog()| Out-Null
}

$AllUsers = AddUserGUI

foreach($User in $AllUsers){write-host $User}

foreach循环不会产生任何输出。如何正确返回此数组列表？

Answer 1

在返回之前，请使用前导，以防止管道将其展开为元素流:

function return-arraylist
 {
   $arraylist = new-object collections.arraylist
   [void]$arraylist.Add('Item one')
   [void]$arraylist.Add('Item two')
   return ,$arraylist
 }

 (return-arraylist).gettype()



IsPublic IsSerial Name                                     BaseType                          
-------- -------- ----                                     --------                          
True     True     ArrayList                                System.Object