April 23rd 2018

In this demo I will be showing how to put PlaceHolder text on Textbox control on Powershell WPF (Windows presentation framework) GUI. here I have 3 textboxes. When I launches GUI, all the textboxes shows darkgray color watermark text information. When I click on them text will disappear and you can start typing your own text without removing anything. If there is no text on the box or empty and when you move on to another box, It will show the default help message automatically.

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I have created default XAML form with visual studio. Textbox color is Darkgray, I have found 2 events on .NET API Reference documentation by Microsoft. I have given 2 url below, It shows how to achieve watermark textbox.
https://msdn.microsoft.com/en-us/library/system.windows.forms.control.gotfocus(v=vs.110).aspx
https://msdn.microsoft.com/en-us/library/system.windows.forms.control.lostfocus(v=vs.110).aspx

There are two main events gotfocus and lostfocus. This defines if there is no text what will happened when I click textbox or click another textbox. Here in the first event gotfocus, When I click on the text box, if it finds text is 'Type valid First Name', Textbox becomes empty and color is changed to black.

$FirstName.Add_GotFocus({
if ($FirstName.Text -eq 'Type valid First Name') {
$FirstName.Foreground = 'Black'
$FirstName.Text = ''
}
})

In the next when I click somewhere else on any other control, and if textbox is empty it will change the text to 'Type valid First Name' and color will change to default one Darkgray.

$FirstName.Add_LostFocus({
if ($FirstName.Text -eq '') {
$FirstName.Text = 'Type valid First Name'
$FirstName.Foreground = 'Darkgray'
}
})

You can download this script here, it is also available on github.com.

#Load required libraries
Add-Type -AssemblyName PresentationFramework, PresentationCore, WindowsBase, System.Windows.Forms, System.Drawing 

[xml]$xaml = @"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApplication2"

        Title="PlaceHolder Text Demo" Height="141" Width="300" Topmost="True">
    
        
        
        

    


"@

#Read the form
$Reader = (New-Object System.Xml.XmlNodeReader $xaml) 
$Form = [Windows.Markup.XamlReader]::Load($reader) 

#AutoFind all controls
$xaml.SelectNodes("//*[@*[contains(translate(name(.),'n','N'),'Name')]]")  | ForEach-Object { 
  New-Variable  -Name $_.Name -Value $Form.FindName($_.Name) -Force 
}

#Textbox Placeholder Remove Default text when textbox clicked
$FirstName.Add_GotFocus({
    
    if ($FirstName.Text -eq 'Type valid First Name') {
        $FirstName.Foreground = 'Black'
        $FirstName.Text = ''
    }
})
#Textbox placeholder grayed out text when textbox clicked
$FirstName.Add_LostFocus({
    if ($FirstName.Text -eq '') {
        $FirstName.Text = 'Type valid First Name'
        $FirstName.Foreground = 'Darkgray'
    }
})

#Textbox placeholder remove default text when textbox clicked
$LastName.Add_GotFocus({
    
    if ($LastName.Text -eq 'Type valid Last Name') {
        $LastName.Foreground = 'Black'
        $LastName.Text = ''
    }
})
#Textbox placeholder grayed out text when textbox clicked
$LastName.Add_LostFocus({
    if ($LastName.Text -eq '') {
        $LastName.Text = 'Type valid Last Name'
        $LastName.Foreground = 'Darkgray'
    }
})

#Textbox placeholder remove default text when textbox clicked
$Contry.Add_GotFocus({
    
    if ($Contry.Text -eq 'Type valid contry') {
        $Contry.Foreground = 'Black'
        $Contry.Text = ''
    }
})
#Textbox placeholder grayed out text when textbox clicked
$Contry.Add_LostFocus({
    if ($Contry.Text -eq '') {
        $Contry.Text = 'Type valid contry'
        $Contry.Foreground = 'Darkgray'
    }
})

#Mandetory last line of every script to load form
$Form.ShowDialog()

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This post first appeared on Tales From Real IT System Administrators World And Non-production Environment, please read the originial post: here