根据选择的另一个组合框填充组合框 - Powershell

Question

我正在创建一个带有两个组合框的 powershell GUI。 第一个包含国家，第二个应该根据在第一个组合框中选择的国家/地区填充城市

例如，当在组合框 1 中选择“美国”时，“纽约”、“底特律”和“西雅图”应该出现在组合框 2 中，当在组合框 1 中选择“英格兰”时，“伦敦”和“埃塞克斯”应该出现在combobox2等等

这是我的脚本的一个非常简短的版本：

$Countries=@("USA","England","Canada")

$CitiesUS=@("New York","Detroit","Seattle")
$CitiesEN=@("London","Essex")
$CitiesCA=@("Toronto","Vancouver")

$Form                                  =      New-Object System.Windows.Forms.Form
$Form.Size                             =      New-Object System.Drawing.Size(300,300)  
$Combobox1                             =      New-Object System.Windows.Forms.Combobox
$Combobox1.Location                    =      New-Object System.Drawing.Size(26,50)  
$Combobox1.Size                        =      New-Object System.Drawing.Size(105,20)
$Combobox1.items.AddRange($Countries)
$combobox2                             =      New-Object System.Windows.Forms.Combobox
$combobox2.Location                    =      New-Object System.Drawing.Size(143,50)  
$combobox2.Size                        =      New-Object System.Drawing.Size(105,20)
$Form.Controls.Add($combobox1)
$Form.Controls.Add($combobox2)

## combobox function

if     ($combobox1.SelectedItem -eq ("USA")) {
       $combobox2.Items.Clear()
       foreach ($City in $CitiesUS) {
       $combobox2.Items.Add($City)}
       }

$Form.ShowDialog()

为了这个例子，我为一个国家添加了一个简单的 IF 语句，但即使这样也不起作用。 几天来我一直在研究如何做到这一点，但找不到任何东西或无法完全理解某些解决方案。有一些简单的方法可以做到这一点吗？

感谢任何帮助！

Answer 1

见我上面的评论，类似这样：

$Countries=@("USA","England","Canada")

$CitiesUS=@("New York","Detroit","Seattle")
$CitiesEN=@("London","Essex")
$CitiesCA=@("Toronto","Vancouver")

$Form                                  =      New-Object System.Windows.Forms.Form
$Form.Size                             =      New-Object System.Drawing.Size(300,300)  
$Combobox1                             =      New-Object System.Windows.Forms.Combobox
$Combobox1.Location                    =      New-Object System.Drawing.Size(26,50)  
$Combobox1.Size                        =      New-Object System.Drawing.Size(105,20)
$Combobox1.items.AddRange($Countries)
$combobox2                             =      New-Object System.Windows.Forms.Combobox
$combobox2.Location                    =      New-Object System.Drawing.Size(143,50)  
$combobox2.Size                        =      New-Object System.Drawing.Size(105,20)
$Form.Controls.Add($combobox1)
$Form.Controls.Add($combobox2)
# Populate Combobox 2 When Combobox 1 changes
$ComboBox1_SelectedIndexChanged= {
    $combobox2.Items.Clear() # Clear the list
    $combobox2.Text = $null  # Clear the current entry
    Switch ($ComboBox1.Text) {
        "USA" {        
            $CitiesUS | ForEach { $combobox2.Items.Add($_) }
        }
        "England" {
            $CitiesEN | ForEach { $combobox2.Items.Add($_) }
        }
        "Canada" {
            $CitiesCA | ForEach { $combobox2.Items.Add($_) }
        }
    }
}

$ComboBox1.add_SelectedIndexChanged($ComboBox1_SelectedIndexChanged)

$Form.ShowDialog()