How to show placeholder text in a WPF TextBox in C# and VB

Originally published:

Sometimes, when you have a text box in a user interface, you may want to add placeholder text to that text box to give users a prompt as to what to enter into the text box. If you've ever used UWP or WinUI, you'll probably have noticed that the default text box elements provide a PlaceholderText property that provides this functionality. However, WPF and Windows Forms don't provide this functionality by default. Luckily, thanks to WPF's rendering capabilities, it is quite easy to set up placeholder text manually. If you're using Windows Forms, you can make use of the ElementHost to use a WPF TextBox. Typically, placeholder text is a slightly faded colour compared to user-entered text to help distinguish it and only shows when no text is entered into the text box. An example is below:

WPF TexBox with placeholder text

How to show placeholder text in a WPF TextBox

To show placeholder text in a WPF textbox, all we need to do is show a partially transparent, intangible Label above the TextBox like so (You can replace 'Search...' with your own placeholder test):

<TextBox x:Name="txtSearch"/>

<Label x:Name="txtSearchPlaceholder" Content="Search..." Background="Transparent" Opacity="0.5" IsHitTestVisible="False"/>


Note: This XAML should be pasted within a grid or other element that allows the Label to show on top of the TextBox.
This will show the placeholder text, however, the text will remain there even when the user types in the TextBox. To have the placeholder text only show when there's no text in the TextBox, we need code like this:

C#:

private void txtSearch_TextChanged(Object sender, TextChangedEventArgs e)

{

if (txtSearch.Text != "") {

     txtSearchPlaceholder.Visibility

= Visibility.Hidden;

} else {

    txtSearchPlaceholder.Visibility

= Visibility.Visible;

}

}

VB:

Private Sub txtSearch_TextChanged(sender As Object, e As TextChangedEventArgs)

If txtSearch.Text <> "" Then

txtSearchPlaceholder.Visibility = Visibility.Hidden

Else

txtSearchPlaceholder.Visibility = Visibility.Visible

End If

End Sub


Then be sure to add the event handler to XAML:

<TextBox x:Name="txtSearch" TextChanged="txtSearch_TextChanged"/> 


Did this article help you? Do you have any suggestions for a better way to achieve this? Let us know in the comments.

This snippet is available in Codly. Click the appropriate link below to download the snippet. If you don't have Codly, it is available here in the Microsoft Store.


Follow us to be notified when we release new guides:
Facebook
Twitter
Tags:

Comments

  1. AnonymousSeptember 9, 2023 at 9:45 AM

    A cleaner approach would be to bind the visibility of the placeholder label to the Text property of the textbox with a data converter that returns Hidden when the bound value contains text and Visible when it is empty. This eliminates the need for the Texchanged codebehind.

    ReplyDelete
    Replies
    1. Quinn's Coding GuidesDecember 3, 2023 at 3:55 PM

      Yep, this option could work as well and would make it cleaner.

      Delete

Post a Comment

Popular posts from this blog

How to enable dark title bar in WPF and Windows Forms/WinForms apps in C# and VB

Originally published:
Image
Windows has had a dark mode feature for a long time now, however, as a Windows Forms and/or WPF (Windows Presentation Foundation) developer, you may have noticed that the Windows dark mode does not affect your app at all automatically - in fact the Windows dark mode only automatically affects UWP, WinUI and Chromium based user interfaces - there's no support for Windows dark mode in Windows Forms and WPF. Tip: If you want to set the title bar's colours to any colours you want instead of just light or dark, follow this guide here . Luckily, it is very easy to determine if dark mode is currently enabled and be notified any time dark mode is switched on or off - from there it's just a matter of updating your UI to match which mode Windows is in. While this may work fine for the client area of your app (i.e. the area of your app that does not include the title bar and border), you don't have a lot of control over the non-client area of your app and you'll notice that by...
Read more

How to use modern icons in XAML in WPF on Windows 10 and 11

Originally published:
Image
Icons and symbols are a common part of modern user interfaces. Depending on your skills, creating your own icons may not be easy. Luckily, Windows 10 and 11 come preinstalled with plenty of icons that can be used in applications. If you've developed for UWP or WinUI and have used the SymbolIcon , you may have seen these icons before. By using these modern icons, you can create user interfaces that look consistent with the operating system. And the great part is that it's easy to use these icons with WPF (Windows Presentation Foundation) while supporting both Windows 10 and 11. 6 WPF buttons with modern icons in Windows 11 The same 6 WPF buttons with modern icons in Windows 10 Where the icons are stored These modern icons that Windows 10 and 11 include come in the form of fonts - specifically Segoe MDL2 Assets and Segoe Fluent Icons . Segoe MDL2 Assets is included in Windows 10 and 11 and Segoe Fluent Icons is included in Windows 11. Segoe Fluent Icons includes newer version...
Read more

How to change the colour of a WPF or Windows Forms/WinForms title bar in Windows 11 in C# and VB

Originally published:
Image
The windows title bar has gone through various changes throughout the years - from the old title bars with user customisable colours to the newer title bars with visual styling support introduced in Windows XP to the DWM (Desktop Window Manager) rendered title bars introduced in Windows Vista. One thing about these changes is that they often explored the concepts the relationship of the title bar to the client area of Windows and who is in control of what the title bar looks like. For example, in Windows XP, the user could only choose between specific title bar styles unless you used the Windows classic theme, in which case you could choose your own title bar colours or even use gradients if you wanted. With the addition of the DWM in Windows Vista, Microsoft explored the idea of extending the title bar into the non client area of Windows - think File Explorer and Microsoft Word for example. Where we are now In modern versions of Windows, the title bar only uses the DWM version and all...
Read more

Microsoft WebView2: How to check if the WebView2 runtime is installed in C# and VB

Originally published:
With the initial release of Windows 10, Microsoft released a completely new web browser - Microsoft Edge - that used its own rendering engine - EdgeHTML. In recent years, Microsoft deprecated the original version of Microsoft Edge and replaced it with a Chromium based version. The original version of Microsoft Edge came with a control called WebView which could be used by apps to display content. Now that Microsoft has released the new Chromium based Edge, a new control has been released called WebView2. The existing WebView control still uses the original Microsoft Edge whereas the new WebView2  uses the Chromium based Microsoft Edge. The new control however, is not reliant on the same version of Microsoft Edge that is used as the main browser - instead it is reliant on a separate component known as the WebView2 Runtime (except in the case of non-stable channels, which come with the WebView2 runtime). This component is preinstalled in Windows 11 and is currently being rolled out ...
Read more