In Powershell how can I change Label text after a successful copy files?-CodePudding

I start building up a small winform with Copy button and a label under this button. When I click on Copy button it starts to copy files from source to destination. I would like to run this asynchroniously so I don't want form to be freezed while copy operation runs. That's why I use Job. After a successful copy I need feedback of copy and show an "OK" text with green color but it is not working.

Here is my code:

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

Function Copy-Action{

    $Computername = "testclient"

    $Source_Path = "C:\temp\"
    $Destination_Path = "\\$Computername\c$\temp"


    $job = Start-Job -Name "Copy" -ArgumentList $Source_Path,$Destination_Path –ScriptBlock {
           param($Source_Path,$Destination_Path) 
                    
           Copy-Item $Source_Path -Destination $Destination_Path -Recurse -Force
            
            } 
 
    Register-ObjectEvent $job StateChanged -MessageData $Status_Label -Action {
        [Console]::Beep(1000,500)
        $Status_Label.Text = "OK"
        $Status_Label.ForeColor = "#009900"
        $eventSubscriber | Unregister-Event
        $eventSubscriber.Action | Remove-Job
        } | Out-Null
}

# DRAW FORM
$form_MainForm = New-Object System.Windows.Forms.Form
$form_MainForm.Text = "Test Copy"
$form_MainForm.Size = New-Object System.Drawing.Size(200,200)
$form_MainForm.FormBorderStyle = "FixedDialog"
$form_MainForm.StartPosition = "CenterScreen"
$form_MainForm.MaximizeBox = $false
$form_MainForm.MinimizeBox = $true
$form_MainForm.ControlBox = $true

# Copy Button
$Copy_Button = New-Object System.Windows.Forms.Button
$Copy_Button.Location = "50,50"
$Copy_Button.Size = "75,30"
$Copy_Button.Text = "Copy"
$Copy_Button.Add_Click({Copy-Action})
$form_MainForm.Controls.Add($Copy_Button)

# Status Label
$Status_Label = New-Object System.Windows.Forms.Label
$Status_Label.Text = ""
$Status_Label.AutoSize = $true
$Status_Label.Location = "75,110"
$Status_Label.ForeColor = "black"
$form_MainForm.Controls.Add($Status_Label)

#show form
$form_MainForm.Add_Shown({$form_MainForm.Activate()})
[void] $form_MainForm.ShowDialog()

Copy is successful but showing an "OK" label won't. I have placed a Beep but it doesn't work too. What am I doing wrong ? Any solution to this? Thank you.

CodePudding user response：

Start-Job creates a separate process, and when your form is ready to receive events, it can't listen to job events. You need to create a new runspace, which is able to synchronize thread and form control.

I adapted code from this answer. You can read much better explanation there.

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

Function Copy-Action{

    $SyncHash = [hashtable]::Synchronized(@{TextBox = $Status_Label})
    $Runspace = [runspacefactory]::CreateRunspace()
    $Runspace.ThreadOptions = "UseNewThread"
    $Runspace.Open()
    $Runspace.SessionStateProxy.SetVariable("SyncHash", $SyncHash)          
    $Worker = [PowerShell]::Create().AddScript({
        $SyncHash.TextBox.Text = "Copying..."
        
        # Copy-Item
        $Computername = "testclient"

        $Source_Path = "C:\temp\"
        $Destination_Path = "\\$Computername\c$\temp"

        Copy-Item $Source_Path -Destination $Destination_Path -Recurse -Force

        
        $SyncHash.TextBox.ForeColor = "#009900"
        $SyncHash.TextBox.Text = "OK"

    })
    $Worker.Runspace = $Runspace
    $Worker.BeginInvoke()

}

# DRAW FORM
$form_MainForm = New-Object System.Windows.Forms.Form
$form_MainForm.Text = "Test Copy"
$form_MainForm.Size = New-Object System.Drawing.Size(200,200)
$form_MainForm.FormBorderStyle = "FixedDialog"
$form_MainForm.StartPosition = "CenterScreen"
$form_MainForm.MaximizeBox = $false
$form_MainForm.MinimizeBox = $true
$form_MainForm.ControlBox = $true

# Copy Button
$Copy_Button = New-Object System.Windows.Forms.Button
$Copy_Button.Location = "50,50"
$Copy_Button.Size = "75,30"
$Copy_Button.Text = "Copy"
$Copy_Button.Add_Click({Copy-Action})
$form_MainForm.Controls.Add($Copy_Button)

# Status Label
$Status_Label = New-Object System.Windows.Forms.Label
$Status_Label.Text = ""
$Status_Label.AutoSize = $true
$Status_Label.Location = "75,110"
$Status_Label.ForeColor = "black"
$form_MainForm.Controls.Add($Status_Label)

#show form
$form_MainForm.Add_Shown({$form_MainForm.Activate()})
[void] $form_MainForm.ShowDialog()

CodePudding user response：

It might have to do with the order of your codeblocks.

After setting the label text to "OK", it is overwritten by the initializing statement

$Status_Label.Text = ""

and maybe thus not showing the updated value. Try to put the function on the bottom of your script or at least put the block of the label above the block where the label text is set, like:

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

Function Copy-Action{

    $Computername = "testclient"

    $Source_Path = "C:\temp\"
    $Destination_Path = "\\$Computername\c$\temp"


    $job = Start-Job -Name "Copy" -ArgumentList $Source_Path,$Destination_Path –ScriptBlock {
           param($Source_Path,$Destination_Path) 
                    
           Copy-Item $Source_Path -Destination $Destination_Path -Recurse -Force
            
            } 
 
    Register-ObjectEvent $job StateChanged -MessageData $Status_Label -Action {
        [Console]::Beep(1000,500)
        $Status_Label.Text = "OK"
        $Status_Label.ForeColor = "#009900"
        $eventSubscriber | Unregister-Event
        $eventSubscriber.Action | Remove-Job
        } | Out-Null
}

# DRAW FORM
$form_MainForm = New-Object System.Windows.Forms.Form
$form_MainForm.Text = "Test Copy"
$form_MainForm.Size = New-Object System.Drawing.Size(200,200)
$form_MainForm.FormBorderStyle = "FixedDialog"
$form_MainForm.StartPosition = "CenterScreen"
$form_MainForm.MaximizeBox = $false
$form_MainForm.MinimizeBox = $true
$form_MainForm.ControlBox = $true

# Status Label
$Status_Label = New-Object System.Windows.Forms.Label
$Status_Label.Text = ""
$Status_Label.AutoSize = $true
$Status_Label.Location = "75,110"
$Status_Label.ForeColor = "black"
$form_MainForm.Controls.Add($Status_Label)

# Copy Button
$Copy_Button = New-Object System.Windows.Forms.Button
$Copy_Button.Location = "50,50"
$Copy_Button.Size = "75,30"
$Copy_Button.Text = "Copy"
$Copy_Button.Add_Click({Copy-Action})
$form_MainForm.Controls.Add($Copy_Button)

#show form
$form_MainForm.Add_Shown({$form_MainForm.Activate()})
[void] $form_MainForm.ShowDialog()