mirror of
https://github.com/Stone-Red-Code/docs-desktop.git
synced 2026-09-06 16:06:07 +02:00
Andy De GeorgeandGenevieve Warren
184e6c9a0c
* Migrate inprogress winforms contnet from docs * Fix preview note * Fix vb code * Minor fixes to keyboard articles * Minor adjustment to overview * Test redirects for 4.0 -> 5.0 * adjust links * Add mouse input section winforms (#81) * Update projects to .NET 5 * Update keyboard desc * Finish mouse events * Add remaining mouse articles;code * finish mouse input * minor fixes * Remove branch restriction (#82) * Update build-validation.yml (#84) * Update build-validation.yml (#85) * Fix vb proj * Add WinForms tutorial (#91) * redirect between overview * New create an app tutorial * Fix markdown * Fix preserve view setting * Add forms articles (#93) * Add forms articles * Fix warnings * Winforms publish (#95) * Prep TOC for publish * Updated date * Automatic how-to topic type * Update desc/headers * Fix links * Fix build errors * Add preview note * Update toc landing page * Convert old style project files * update download links * Apply suggestions from code review Co-authored-by: Genevieve Warren <[email protected]> * Adjust number key * Update dotnet-desktop-guide/net/winforms/overview/index.md * Try toc position task via bookmark * Improve images * Remove sentence * File redirects Co-authored-by: Genevieve Warren <[email protected]>
61 lines
4.0 KiB
Markdown
61 lines
4.0 KiB
Markdown
---
|
|
title: "Modify keyboard key events"
|
|
description: Learn how to intercept a key press and modify which key is pressed on a Windows Forms .NET application.
|
|
ms.date: 10/26/2020
|
|
dev_langs:
|
|
- "csharp"
|
|
- "vb"
|
|
helpviewer_keywords:
|
|
- "keyboard input [Windows Forms], modifying"
|
|
- "modifying keyboard input"
|
|
- "Windows Forms, modifying keyboard input"
|
|
- "keyboards [Windows Forms], keyboard input"
|
|
---
|
|
# How to modify keyboard key events (Windows Forms .NET)
|
|
|
|
Windows Forms provides the ability to consume and modify keyboard input. Consuming a key refers to handling a key within a method or event handler so that other methods and events further down the message queue don't receive the key value. And, modifying a key refers to modifying the value of a key so that methods and event handlers further down the message queue receive a different key value. This article shows how to accomplish these tasks.
|
|
|
|
[!INCLUDE [desktop guide under construction](../../includes/desktop-guide-preview-note.md)]
|
|
|
|
## Consume a key
|
|
|
|
In a <xref:System.Windows.Forms.Control.KeyPress> event handler, set the <xref:System.Windows.Forms.KeyPressEventArgs.Handled%2A> property of the <xref:System.Windows.Forms.KeyPressEventArgs> class to `true`.
|
|
|
|
-or-
|
|
|
|
In a <xref:System.Windows.Forms.Control.KeyDown> event handler, set the <xref:System.Windows.Forms.KeyEventArgs.Handled%2A> property of the <xref:System.Windows.Forms.KeyEventArgs> class to `true`.
|
|
|
|
> [!NOTE]
|
|
> Setting the <xref:System.Windows.Forms.KeyEventArgs.Handled%2A> property in the <xref:System.Windows.Forms.Control.KeyDown> event handler does not prevent the <xref:System.Windows.Forms.Control.KeyPress> and <xref:System.Windows.Forms.Control.KeyUp> events from being raised for the current keystroke. Use the <xref:System.Windows.Forms.KeyEventArgs.SuppressKeyPress%2A> property for this purpose.
|
|
|
|
The following example handles the <xref:System.Windows.Forms.Control.KeyPress> event to consume the `A` and `a` character keys. Those keys can't be typed into the text box:
|
|
|
|
:::code language="csharp" source="snippets/how-to-change-key-press/csharp/Form1.cs" id="ConsumeKey":::
|
|
:::code language="vb" source="snippets/how-to-change-key-press/vb/Form1.vb" id="ConsumeKey":::
|
|
|
|
## Modify a standard character key
|
|
|
|
In a <xref:System.Windows.Forms.Control.KeyPress> event handler, set the <xref:System.Windows.Forms.KeyPressEventArgs.KeyChar%2A> property of the <xref:System.Windows.Forms.KeyPressEventArgs> class to the value of the new character key.
|
|
|
|
The following example handles the <xref:System.Windows.Forms.Control.KeyPress> event to change any `A` and `a` character keys to `!`:
|
|
|
|
:::code language="csharp" source="snippets/how-to-change-key-press/csharp/Form1.cs" id="ModifyKey":::
|
|
:::code language="vb" source="snippets/how-to-change-key-press/vb/Form1.vb" id="ModifyKey":::
|
|
|
|
## Modify a non-character key
|
|
|
|
You can only modify non-character key presses by inheriting from the control and overriding the <xref:System.Windows.Forms.Control.PreProcessMessage%2A> method. As the input <xref:System.Windows.Forms.Message> is sent to the control, it's processed before the control raising events. You can intercept these messages to modify or block them.
|
|
|
|
The following code example demonstrates how to use the <xref:System.Windows.Forms.Message.WParam%2A> property of the <xref:System.Windows.Forms.Message> parameter to change the key pressed. This code detects a key from <kbd>F1</kbd> through <kbd>F10</kbd> and translates the key into a numeric key ranging from <kbd>0</kbd> through <kbd>9</kbd> (where <kbd>F10</kbd> maps to <kbd>0</kbd>).
|
|
|
|
:::code language="csharp" source="snippets/how-to-change-key-press/csharp/NewTextBox.cs" id="PreProcessMessage":::
|
|
:::code language="vb" source="snippets/how-to-change-key-press/vb/NewTextBox.vb" id="PreProcessMessage":::
|
|
|
|
## See also
|
|
|
|
- [Overview of using the keyboard (Windows Forms .NET)](overview.md)
|
|
- [Using keyboard events (Windows Forms .NET)](events.md)
|
|
- <xref:System.Windows.Forms.Keys>
|
|
- <xref:System.Windows.Forms.Control.KeyDown>
|
|
- <xref:System.Windows.Forms.Control.KeyPress>
|