Powershell : When event handler is inside for loop, Checkbox change event does not give valid result

I created an array of Check boxes. I could create a event handler for each check box separately but as it would be lengthy code I thought if I could create them using loop. When event handler is written inside loop the event is being handled but the result shown is wrong i.e -> when I select i'th check box the event is handled but $checkBox_Charts[$i].Checked is always returning False whether the box is checked or unchecked.

Code Snippet:

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

    # Set the size of your form
    $Form = New-Object System.Windows.Forms.Form
    $Form.width = 1000
    $Form.height = 600
    $Form.Text = ”xxx”

    # Creating array of Checkbox objects  
    $checkBox_Charts =[System.Windows.Forms.checkbox[]]::new(10)

    $index_checkBox_Charts=0
    # defining values to array of Checkbox objects 
    foreach ($key_chart in $charts.Keys){
        $CheckBox = new-object System.Windows.Forms.checkbox       
        $CheckBox.Text = $key_chart
        $checkBox_Charts[$index_checkBox_Charts] = $CheckBox    
        $index_checkBox_Charts++
    }

    # Create a group that will contain your checkbox buttons
    $MyGroupBox = New-Object System.Windows.Forms.GroupBox
    $MyGroupBox.text = "xxx"

    # Add the check box array to GroupBox
    $MyGroupBox.Controls.AddRange(@($checkBox_Charts))

    # Add the GroupBox to Form   
    $Form.Controls.AddRange(@($MyGroupBox))
    ###########  This is the important piece ##############
    #                                                     #
    # Do something when the state of the checkbox changes #
    #######################################################

    #Trying to create event handler for all check boxes in array in for loop than writing separately for checkbox
    for($i=0; $i -lt 10; $i++){
        $checkBox_Charts[$i].Add_CheckStateChanged({
            $charts[$checkBox_Charts[$i]] =$checkBox_Charts[$i].Checked 
            Write-Host "CP2: in Add_CheckStateChanged " + $checkBox_Charts[$i].Checked
            Write-Host $checkBox_Charts[$i]
        })
    }     
    # Activate the form
    $Form.Add_Shown({$Form.Activate()})
    [void] $Form.ShowDialog() 
}

#Call the function
checkbox_test