onkeydown JavaScript (JS) Example: HTML DOM Objects – Event – onkeydown JavaScript (JS) Example
3-Minute Video Tour of LearnVisualStudio.NET by Bob Tabor
Premium (Not Free) Video Tutorials
Free Video Tutorials & Free Tools
onkeydown JavaScript (JS) Example: HTML DOM Objects – Event – onkeydown JavaScript (JS) Example
Purpose: – Illustrates the JavaScript syntax for the onkeydown Event.
Prerequistes:
- Install Visual Web Developer 2008
Syntax: Object.onkeydown="yourjavascriptcode()" – Allows you to know when a keybord key has been pressed.
Restrictions: None
Notes:
- You can build your own library of syntax examples by using same web site over and over and just add new files to it.
Instructions:
- Use Visual Web Developer 2008
- Create new web site;
- Click File/New Web Site
- Select ASP.NET Website Template
- Select C-Sharp for language
- name of Web Site could be JavaScript_Syntax.
- Add New folder named "HTMLDOMObjects"
- Right-click project name in solution explorer;
- add new folder;
- name of folder should be: HTMLDOMObjects
- Add New subfolder to "HTMLDOMObjects" folder named "DOMEvent"
- Right-click folder named "HTMLDOMObjects" in solution explorer;
- add new folder;
- name of folder should be: DOMEvent
- Add New subfolder to "DOMEvent" subfolder named "EventHandlers"
- Right-click subfolder named "DOMEvent" in solution explorer;
- add new folder;
- name of folder should be: EventHandlers
- Add HTML Page Named onkeydown to EventHandlers subfolder
- Right-click EventHandlers subfolder;
- add new item;
- Select HTML Page
- HTML Page name should be onkeydown
- Click on copy code in code below to copy code into HTML Page onkeydown.htm
- Right-click on HTML page onkeydown.htm and select view in browser
| HTML | | | | ? |
< !DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> |
<html> |
<head> |
<title>IdealProgrammer.com: onkeydown </title> |
<!-- |
*************************************************** |
* This example is from http://idealprogrammer.com * |
*************************************************** |
***************************************************** |
DOM Objects |
***************************************************** |
***************************************************** |
*** DOM Event - EventHandlers *** |
***************************************************** |
***************************************************** |
*** onkeydown |
***************************************************** |
SYNTAX: |
object.onkeydown="yourjavascriptcode()" Allows you to know when a key has been |
pressed |
================================================================= |
An EXCELLENT tutorial on event basics can be found at: |
http://www.quirksmode.org/js/introevents.html |
================================================================= |
You can access the following properties thru the event handler: |
Available Properties |
altKey Retrieves a value that indicates the state of the ALT key. |
altLeft Retrieves a value that indicates the state of the left ALT key. |
clientX Sets or retrieves the x-coordinate of the mouse pointer's position relative to the client area of the window, excluding window decorations and scroll bars. |
clientY Sets or retrieves the y-coordinate of the mouse pointer's position relative to the client area of the window, excluding window decorations and scroll bars. |
ctrlLeft Sets or retrieves the state of the left CTRL key. |
offsetX Sets or retrieves the x-coordinate of the mouse pointer's position relative to the object firing the event. |
offsetY Sets or retrieves the y-coordinate of the mouse pointer's position relative to the object firing the event. |
returnValue Sets or retrieves the return value from the event. |
screenX Sets or retrieves the x-coordinate of the mouse pointer's position relative to the user's screen. |
screenY Sets or retrieves the y-coordinate of the mouse pointer's position relative to the user's screen. |
shiftLeft Retrieves the state of the left SHIFT key. |
srcElement Sets or retrieves the object that fired the event. |
type Sets or retrieves the event name from the event object. |
x Sets or retrieves the x-coordinate (in pixels) of the mouse pointer's offset from the closest relatively positioned parent element of the element that fired the event. |
y Sets or retrieves the y-coordinate (in pixels) of the mouse pointer's offset from the closest relatively positioned parent element of the element that fired the event. |
The captureEvents() method captures all the events of the event type passed. |
When you have multiple events to capture, separate them with the pipe, |, character. |
Here are the types of event you can capture: |
Event.ABORT |
Event.BLUR |
Event.CHANGE |
Event.CLICK |
Event.DBLCLICK |
Event.DRAGDROP |
Event.ERROR |
Event.FOCUS |
Event.KEYDOWN |
Event.KEYPRESS |
Event.KEYUP |
Event.LOAD |
Event.MOUSEDOWN |
Event.MOUSEMOVE |
Event.MOUSEOUT |
Event.MOUSEOVER |
Event.MOUSEUP |
Event.MOVE |
Event.RESET |
Event.RESIZE |
Event.SELECT |
Event.SUBMIT |
Event.UNLOAD |
--> |
<!-- Script for example 1 --> |
<script type="text/javascript"> |
function onlyNumbers(e) { |
var charCode |
var evt = e || window.event; |
charCode = evt.keyCode; |
if (charCode > 31 && (charCode < 48 || charCode > 57)) |
return false; |
return true; |
} |
</script> |
<!-- Script for example 2 --> |
<script type="text/javascript"> |
function inlineAge(e) { |
var charCode; |
var evt = e || window.event; |
charCode = evt.keyCode; |
if (charCode > 31 && (charCode < 48 || charCode > 57)) |
return false; |
return true; |
} |
</script> |
</head> |
<body> |
<h2>Example #1: Demonstrates onkeydown for only allowing numbers in field using recommended technique for registering events</h2> |
Numbers Only: <input type="text" |
id="NumbersOnly" /> |
<br /> |
<br /> |
<!-- Script for example 1 --> |
<script type="text/javascript"> |
// This is the "traditional" and recommended technique for registering an event |
// handler because it allows you to separate structure from behavior; the |
// "inline" method of registering an event within xhtml tags is not |
// the recommended approach because it blurs structure and behavior. |
// For complete explanation, please see the following excellent article: |
// http://www.digital-web.com/articles/separating_behavior_and_structure_2/ |
// |
// Note: Using getElementById so registering event will work in FireFox |
// |
var NumbersOnly = document.getElementById("NumbersOnly") |
NumbersOnly.onkeydown = onlyNumbers; |
</script> |
<hr /> |
<h2>Example #2: Using In-line javascript is simplier, but blurs structure and behavior</h2> |
Age: <input type="text" |
onkeydown="return inlineAge(event)" id="Text1" /> |
<br /> <br /> |
</body> |
</html> |
Related posts:
- onerror JavaScript (JS) Example: HTML DOM Objects – Event – onerror JavaScript (JS) Example onerror JavaScript (JS) Example: HTML DOM Objects - Event -...
- onfocus JavaScript (JS) Example: HTML DOM Objects – Event – onfocus JavaScript (JS) Example onfocus JavaScript (JS) Example: HTML DOM Objects - Event -...
- onBlur JavaScript (JS) Example: HTML DOM Objects – Event – onBlur JavaScript JS Example onBlur JavaScript (JS) Example HTML DOM Objects Event...
- onChange JavaScript (JS) Example: HTML DOM Objects – Event – onChange JavaScript (JS) Example onChange JavaScript (JS) Example: HTML DOM Objects - Event -...
- ondblclick JavaScript (JS) Example: HTML DOM Objects – Event – ondblclick JavaScript (JS) Example ondblclick JavaScript (JS) Example: HTML DOM Objects - Event -...
Related posts brought to you by Yet Another Related Posts Plugin.
Comments
One Response to “onkeydown JavaScript (JS) Example: HTML DOM Objects – Event – onkeydown JavaScript (JS) Example”Trackbacks
Check out what others are saying about this post...[...] object.onerrorEvent happens when an error occurs.onfocusEvent happens when an element gains focus.onkeydownEvent happens when a key is pressed.onkeypressEvent happens when key is held down or [...]