您可以像这样获取对checked/unchecked CheckBox元素的引用：

[System.Windows.RoutedEventHandler]$uncheckedHandler = {
   $e = [System.Windows.RoutedEventArgs]$args[1]
   $checkBox = [System.Windows.Controls.CheckBox]$e.OriginalSource
   $dataObject = $checkBox.DataContext
   $itemName = $dataObject.name
}

在使用带有自定义DataTemplate的ComboBox时，要在处理程序中获取单击的项对象，可以结合使用ComboBox的DropDownClosed事件和SelectedItem属性。以下是如何修改PowerShell代码来实现这一点：

# Define the Click event handler for the CheckBox
[System.Windows.RoutedEventHandler]$clickHandler = {
    $checkBox = $args[0]  # The CheckBox that was clicked
    $dataContext = $checkBox.DataContext  # The data context of the CheckBox

    # Now you can access properties of the clicked item using $dataContext
    $itemName = $dataContext.name
    $isChecked = $dataContext.ischeck

    # Perform your desired operations based on the clicked item
    if ($isChecked) {
        Write-Host "$itemName is checked."
        # Add your logic for a checked item here
    } else {
        Write-Host "$itemName is unchecked."
        # Add your logic for an unchecked item here
    }
}

# Add the Click event handler to the CheckBoxes
$cbMyItems.AddHandler([System.Windows.Controls.CheckBox]::ClickEvent, $clickHandler)

# Define the DropDownClosed event handler for the ComboBox
[System.Windows.RoutedEventHandler]$dropDownClosedHandler = {
    $selectedItem = $cbMyItems.SelectedItem
    if ($selectedItem -ne $null) {
        # Perform your next operations using $selectedItem here
        # $selectedItem will contain the clicked item
        # You can access its properties as needed
    }
}

# Add the DropDownClosed event handler to the ComboBox
$cbMyItems.AddHandler([System.Windows.Controls.ComboBox]::DropDownClosedEvent, $dropDownClosedHandler)

在此代码中，"CheckBox“的"Click”事件处理程序获取单击的“CheckBox”的数据上下文（即数据项）。然后，您可以访问所单击项目的属性（“$itemName”和“$isitemName”）并执行所需的操作。
"ComboBox“的”DropDownClosed“事件处理程序会在ComboBox关闭时捕获所选项目，您可以将此项目作为**$selectedItem**访问，以根据单击的项目执行进一步的操作。