.net 如何从System.Windows.Forms.TextBox中捕获值？

我找到一篇关于输入框的文章，但它不起作用。我只是从一个在线示例处理代码到PowerShell ISE。我启动它，在填充一个输入框并单击OK/点击enter之后，变量保持为空

可能有什么问题？

代码是：

#test value
$x=1

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

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

$objForm.KeyPreview = $True
$objForm.Add_KeyDown({if ($_.KeyCode -eq "Enter") 
    {$x=$objTextBox.Text;$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=$objTextBox.Text;$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 enter the information in the space below:"
$objForm.Controls.Add($objLabel) 

$objTextBox = New-Object System.Windows.Forms.TextBox 
$objTextBox.Location = New-Object System.Drawing.Size(10,40) 
$objTextBox.Size = New-Object System.Drawing.Size(260,20) 
$objForm.Controls.Add($objTextBox) 

$objForm.Topmost = $True

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

$x

---

执行后，

$x

仍然是1。输入什么并不重要。

使用

$global:x

访问事件处理程序中的变量：

#test value
$x=1

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

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

$objForm.KeyPreview = $True
$objForm.Add_KeyDown({
    if ($_.KeyCode -eq "Enter") {
        $global:x=$objTextBox.Text;
        $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"
$OKButton.Add_Click({$global:x=$objTextBox.Text;$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 enter the information in the space below:"
$objForm.Controls.Add($objLabel) 

$objTextBox = New-Object System.Windows.Forms.TextBox 
$objTextBox.Location = New-Object System.Drawing.Size(10,40) 
$objTextBox.Size = New-Object System.Drawing.Size(260,20) 
$objForm.Controls.Add($objTextBox) 

$objForm.Topmost = $True

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



$x
#it`s still 1 here, doesn`t matter what i input

---

对你想要达到的目标有轻微的改变。即使在文本框中写入内容，然后单击“取消”，也不会显示任何值。试试这个代码-

#test value
$x=1

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

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

$objForm.KeyPreview = $True
$objForm.Add_KeyDown({if ($_.KeyCode -eq "Enter") 
    {$x=$objTextBox.Text;$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=$objTextBox.Text;$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({
$objTextBox.Text = $null
$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 enter the information in the space below:"
$objForm.Controls.Add($objLabel) 

$objTextBox = New-Object System.Windows.Forms.TextBox 
$objTextBox.Location = New-Object System.Drawing.Size(10,40) 
$objTextBox.Size = New-Object System.Drawing.Size(260,20) 
$objForm.Controls.Add($objTextBox) 

$objForm.Topmost = $True

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

$x = $objTextBox.Text
$x

---

你想达到什么目的？它会提示你。如本教程所述，执行后$x的值为1。我想将来自用户promt的文本放入变量。

$x=$objTextBox.text

在最后一行中它已经存在：$ok按钮。添加（单击（{$x=$objTextBox.text；$objForm.Close（））就是不起作用。为什么？好的，它现在可以工作了，但即使我按下cancel或esc，变量也会被填充。您可以在两个EventHandler中重新将值分配到其原始状态，或者在它们中引入另一个变量，并在分配

$x

之前进行检查。请考虑接受这个答案。正如我所看到的，所有的准备都应该是变量赋值$Objult.AddikKEYDOWN（{if（$y.KECODE-EQ）进入“”）$x= $ObjtBox .Text；$Objult.Cutele（）}这是不起作用的。为什么？你是对的。因此，您不必在底部再次分配变量。改为使用全局-查看我编辑的答案。现在它完全按照预期工作。非常感谢。我可以请你更详细地描述一下这是错误的我为什么它不起作用？谢谢。若我按下“Esc”，变量仍然不是空的，但我现在可以自己修复它了。原稿有什么问题？例如，为什么这个字符串不起作用$OKButton.Add_单击（{$x=$objTextBox.Text；$objForm.Close（）}）？