在PowerShell中创建列表框

Question

我正在尝试编写一个包含列表框的PowerShell脚本.为了确保我已经掌握了所需的概念,我在TechNet上查找了一个教程并试图复制所提供的代码.

http://technet.microsoft.com/en-us/library/ff730949.aspx

如果我正确地遵循演练和脚本,则看起来该脚本旨在显示一个对话框,然后将所选项目输出到CLI.我已经复制了对话框,但我无法将选择内容写入CLI.我甚至修改了最后一行来显式调用Write-Output来显示$ x的值.

除了为$ x实际写出任何值之外,关于此脚本的所有内容似乎都按预期工作.由于echo "$x"可能是所有代码中最简单的一行,我只能假设问题实际上是将数据写入 $ x.

下面是我的PowerShell ISE窗口的剪切和粘贴,后者又从上述TechNet文章中剪切并粘贴:

[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Drawing") 

$objForm = New-Object System.Windows.Forms.Form 
$objForm.Text = "Select a Computer"
$objForm.Size = New-Object System.Drawing.Size(300,200) 
$objForm.StartPosition = "CenterScreen"

$objForm.KeyPreview = $True
$objForm.Add_KeyDown({if ($_.KeyCode -eq "Enter") 
    {$x=$objListBox.SelectedItem;$objForm.Close()}})
$objForm.Add_KeyDown({if ($_.KeyCode -eq "Escape") 
    {$objForm.Close()}})

$OKButton = New-Object System.Windows.Forms.Button
$OKButton.Location = New-Object System.Drawing.Size(75,120)
$OKButton.Size = New-Object System.Drawing.Size(75,23)
$OKButton.Text = "OK"
$OKButton.Add_Click({$x=$objListBox.SelectedItem;$objForm.Close()})
$objForm.Controls.Add($OKButton)

$CancelButton = New-Object System.Windows.Forms.Button
$CancelButton.Location = New-Object System.Drawing.Size(150,120)
$CancelButton.Size = New-Object System.Drawing.Size(75,23)
$CancelButton.Text = "Cancel"
$CancelButton.Add_Click({$objForm.Close()})
$objForm.Controls.Add($CancelButton)

$objLabel = New-Object System.Windows.Forms.Label
$objLabel.Location = New-Object System.Drawing.Size(10,20) 
$objLabel.Size = New-Object System.Drawing.Size(280,20) 
$objLabel.Text = "Please select a computer:"
$objForm.Controls.Add($objLabel) 

$objListBox = New-Object System.Windows.Forms.ListBox 
$objListBox.Location = New-Object System.Drawing.Size(10,40) 
$objListBox.Size = New-Object System.Drawing.Size(260,20) 
$objListBox.Height = 80

[void] $objListBox.Items.Add("atl-dc-001")
[void] $objListBox.Items.Add("atl-dc-002")
[void] $objListBox.Items.Add("atl-dc-003")
[void] $objListBox.Items.Add("atl-dc-004")
[void] $objListBox.Items.Add("atl-dc-005")
[void] $objListBox.Items.Add("atl-dc-006")
[void] $objListBox.Items.Add("atl-dc-007")

$objForm.Controls.Add($objListBox) 

$objForm.Topmost = $True

$objForm.Add_Shown({$objForm.Activate()})
[void] $objForm.ShowDialog()

echo "$x"

当上述内容无法按预期工作时,我决定逐步完成本教程并自行重新编写脚本.我修改了一下以更好地适应我的组织偏好并在此过程中添加注释.但是,现在甚至对话本身也被打破了.

# Load Windows Forms & Drawing classes.
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Drawing")

# Create base form.
$objForm = New-Object System.Windows.Forms.Form
$objForm.Text = "Select a Computer"
$objForm.Size = New-Object System.Drawing.Size(300,200)
$objForm.StartPosition = "CenterScreen"

# Configure keyboard intercepts for ESC & ENTER.
$objForm.KeyPreview = $true
$objForm.Add_KeyDown({
    if ($_.KeyCode -eq "Enter")
    {
        $x = $objListBox.SelectedItem
        $objForm.Close()
    }
})
$objForm.Add_KeyDown({
    if ($_.KeyCode -eq "Escape")
    {
        $objForm.Close()
    }
})

# Create OK button.
$OKButton = New-Object System.Windows.Forms.Button
$OKButton.Location = New-Object System.Drawing.Size(75,120)
$OKButton.Size = New-Object System.Drawing.Size(75,23)
$OKButton.Text = "OK"
$OKButton.Add_Click({
    $x = $objListBox.SelectedItem
    $objForm.Close()
})
$objForm.Controls.Add($OKButton)

# Create Cancel button.
$CancelButton = New-Object System.Windows.Forms.Button
$CancelButton.Location = New-Object System.Drawing.Size(150,120)
$CancelButton.Size = New-Object System.Drawing.Size(75,23)
$CancelButton.Text = "Cancel"
$CancelButton.Add_Click({
    $objForm.Close()
})
$objForm.Controls.Add($CancelButton)

# Add form prompt text.
$objLabel = New-Object System.Windows.Forms.Label
$objLabel.Location = New-Object System.Drawing.Size(10,20)
$objLabel.Text = "Please select a computer:"
$objForm.Controls.Add($objLabel)

# Add list box.
$objListBox = New-Object System.Windows.Forms.ListBox
$objListBox.Location = New-Object System.Drawing.Size(10,40)
$objListBox.Size = New-Object System.Drawing.Size(260,20)
$objListBox.Height = 80

# Populate list.
[void] $objListBox.Items.Add("Option1")
[void] $objListBox.Items.Add("Option2")
[void] $objListBox.Items.Add("Option3")
[void] $objListBox.Items.Add("Option4")
[void] $objListBox.Items.Add("Option5")
[void] $objListBox.Items.Add("Option6")
[void] $objListBox.Items.Add("Option7")

# Force list box to display on top of other windows.
$objForm.TopMost = $true

# Display list box.
$objForm.Add_Shown({
    $objForm.Activate()
})
[void] $objForm.ShowDialog()

# Show result.
$x

第二个代码块导致:

我做错了什么,在这里？

注意:我在Windows 7上运行PowerShell 3.0

Answer 1

获取列表框功能的简单方法是使用Out-GridView.例如:

'one','two','three','four' | Out-GridView -OutputMode Single

用户可以选择一个项目,它将在管道中返回.

您还可以-OutputMode Multiple用于多选.

另一个例子:

get-process | Out-GridView -OutputMode Multiple

这将返回所选对象:

Handles  NPM(K)    PM(K)      WS(K) VM(M)   CPU(s)     Id ProcessName
-------  ------    -----      ----- -----   ------     -- -----------
    396      24     5008       8964   113     8,88   3156 AuthManSvr