手动复选框启用

Question

我的表格上有一个ComboBox控件。我想要的是，当我将ComboBox中的项目从一个将事件更改为另一个项目时。在选择同一元素时，请至关重要。一直以来，我一直使用ComboBox.Add_SelectionChangeCommitted($function)，但是很快我意识到，当从列表中选择相同的（选定）项目时，处理程序也执行的块。在Combobox事件中进行一些挖掘，我完全困惑。尝试了几个事件（SelectedItemChanged，SelectedIndexChanged），我永远无法实现所需的结果。

选择相同元素时我想做的事情以及几次不应该做的示例。当执行手册代码块几次时，所有文本框的内容都会清除，但我不想。

Add-Type -AssemblyName System.Windows.Forms
[System.Windows.Forms.Application]::EnableVisualStyles()
$Form                     = New-Object system.Windows.Forms.Form
$Form.ClientSize          = '420,240'
$Form.TopMost             = $false
$Form.FormBorderStyle     = 'Fixed3D'
$Form.MaximizeBox         = $false
$ComboBox                 = New-Object system.Windows.Forms.ComboBox
$ComboBox.width           = 391
$ComboBox.height          = 47
@('Automatic (DHCP)','Manual Input') | ForEach-Object {[void] $ComboBox.Items.Add($_)}
$ComboBox.location        = New-Object System.Drawing.Point(13,57)
$ComboBox.DropDownStyle   = 'DropDownList'
$ComboBox.DrawMode        = 'OwnerDrawFixed'
$Button                   = New-Object system.Windows.Forms.Button
$Button.text              = "Set"
$Button.width             = 60
$Button.height            = 30
$Button.visible           = $false
$Button.enabled           = $false
$Button.location          = New-Object System.Drawing.Point(336,126)
$CheckBox                 = New-Object system.Windows.Forms.CheckBox
$CheckBox.width           = 65
$CheckBox.height          = 15
$CheckBox.visible         = $false
$CheckBox.Checked         = $false
$CheckBox.enabled         = $true
$CheckBox.location        = New-Object System.Drawing.Point(16,210)
$TextBox1                 = New-Object system.Windows.Forms.TextBox
$TextBox1.Name            = "TextBox1"
$TextBox1.multiline       = $false
$TextBox1.width           = 40
$TextBox1.height          = 20
$TextBox1.visible         = $false
$TextBox1.enabled         = $true
$TextBox1.location        = New-Object System.Drawing.Point(81,100)
$TextBox2                 = New-Object system.Windows.Forms.TextBox
$TextBox2.Name            = "TextBox2"
$TextBox2.multiline       = $false
$TextBox2.width           = 40
$TextBox2.height          = 20
$TextBox2.visible         = $false
$TextBox2.enabled         = $false
$TextBox2.location        = New-Object System.Drawing.Point(81,208)
$Form.controls.AddRange(@($TextBox1,$TextBox2,$Button,$ComboBox,$CheckBox))
$global:ManualChecked = $null
$global:AutomaticChecked = $null
$ComboBox.Add_SelectionChangeCommitted($methodSelection)
$netwValues = New-Object 'System.Collections.Hashtable'
$methodSelection = 
{
    switch($ComboBox.Text) 
    { 
        "Manual Input" 
        {
            $CheckBox.Visible = $Button.Visible = $true
            $Button.Enabled = $false 
            ForEach ($control in $Form.controls) 
            {
                if ($control -is [System.Windows.Forms.TextBox] ) 
                {
                    $control.Visible = $control.Enabled = $true
                    $control.Clear()
                    if($netwValues.Count -gt 0)
                    {
                        $control.Text = $netwValues.Item($control.Name)
                        $netwValues.Remove($control.Name)
                    }
                 }
             }
            if($global:ManualChecked -eq 1)
                        {
                            $CheckBox.Checked = $true
                            $TextBox2.Enabled = $true
                        }
                        else
                        {
                            $CheckBox.Checked = $false
                            $TextBox2.Enabled = $false
                        }
        }
        "Automatic (DHCP)" 
        {
            ForEach($control in $Form.controls) 
            {
                if($control -is [System.Windows.Forms.TextBox] -or $control -is [System.Windows.Forms.CheckBox] -or $control -is [System.Windows.Forms.Button]) 
                {
                    $control.Visible = $control.Enabled  = $true
                    if($control -is [System.Windows.Forms.Label] -or $control -is [System.Windows.Forms.TextBox]) 
                    {
                        $control.Enabled = $false
                        if($control -is [System.Windows.Forms.TextBox]) 
                        {
                            if($control.Text.Length)
                            {
                                $netwValues.Add($control.Name,$control.Text)
                                $control.Clear()
                            }
                        }
                    }
                }
            }
            if($global:AutomaticChecked -eq 1)
            {
                $CheckBox.Checked = $true
            }
            else
            {
                $CheckBox.Checked  = $false
            }  
        }
    }
}

Answer 1

您可以自己实现此逻辑。

# Simple class for using as item for combobox instead of just string.
class CbItem
{
    CbItem([string] $value)
    {
        $this.Value = $value
    }
    [string] $Value
    [string] ToString()
    {
        return $this.Value
    }
}
# Add instances of this class into combobox.
$ComboBox.Items.Add([CbItem]::new('Automatic (DHCP)'))
$ComboBox.Items.Add([CbItem]::new('Manual Input'))
# Create a variable for storing current combobox's item.
$global:CurrentCbItem = $null
# Add logic at the begining of handler for exiting if selected item is the same as the last one.
$methodSelection = 
{
    if ([Object]::ReferenceEquals($global:CurrentCbItem, $ComboBox.SelectedItem))
    {
        return
    }
    $global:CurrentCbItem = $ComboBox.SelectedItem
    ...
}