keydown
El evento keydown
se produce cuando se presiona una tecla.
A diferencia del evento keypress
, el evento keydown
es producido por todas las teclas, independientemente de si estas son caracteres o no.
Información general
- Especificación
- DOM L3
- Interfaz
- KeyboardEvent
- Burbuja
- Si
- Cancelable
- Si
- Objetivo
- Document, Element
- Acción
- Varía: evento
keypress
; lanza el sistema de composición de texto; eventosblur
yfocus
;DOMActivate
evento; otro evento
Propiedades
Property | Type | Description |
---|---|---|
target Read only |
EventTarget | The event target (the topmost target in the DOM tree). |
type Read only |
DOMString | The type of event. |
bubbles Read only |
Boolean | Whether the event normally bubbles or not |
cancelable Read only |
Boolean | Whether the event is cancellable or not? |
view Read only |
WindowProxy | document.defaultView (window of the document) |
detail Read only |
long (float ) |
0. |
target Read only |
EventTarget (DOM element) | Focused element processing the key event, root element if no suitable input element focused. |
char Read only |
DOMString (string) | The character value of the key. If the key corresponds to a printable character, this value is a non-empty Unicode string containing that character. If the key doesn't have a printable representation, this is an empty string. See key names and char values for the detail.
Note: If the key is used as a macro that inserts multiple characters, this attribute's value is the entire string, not just the first character.
|
key Read only |
DOMString (string) | The key value of the key represented by the event. If the value has a printed representation, this attribute's value is the same as the char attribute. Otherwise, it's one of the key value strings specified in Key values. If the key can't be identified, this is the string "Unidentified". See key names and char values for the detail. Read Only. |
charCode Read only |
Unsigned long (int) | The Unicode reference number of the key; this attribute is used only by the keypress event. For keys whose char attribute contains multiple characters, this is the Unicode value of the first character in that attribute.
Warning: This attribute is deprecated; you should use
char instead, if available. |
keyCode Read only |
Unsigned long (int) | A system and implementation dependent numerical code identifying the unmodified value of the pressed key. This is usually the decimal ASCII (RFC 20) or Windows 1252 code corresponding to the key; see Virtual key codes for a list of common values. If the key can't be identified, this value is 0.
Warning: This attribute is deprecated; you should use
key instead, if available. |
which Read only |
Unsigned long (int) | A system and implementation dependent numeric code identifying the unmodified value of the pressed key; this is usually the same as keyCode .
Warning: This attribute is deprecated; you should use
key instead, if available. |
location Read only |
long (float) | The location of the key on the device. |
repeat Read only |
boolean | true if a key has been depressed long enough to trigger key repetition, otherwise false . |
locale Read only |
string | The language code for the key event, if available; otherwise, the empty string. |
ctrlKey Read only |
boolean | true if the control key was down when the event was fired. false otherwise. |
shiftKey Read only |
boolean | true if the shift key was down when the event was fired. false otherwise. |
altKey Read only |
boolean | true if the alt key was down when the event was fired. false otherwise. |
metaKey Read only |
boolean | true if the meta key was down when the event was fired. false otherwise. |
preventDefault()
del evento keydown
Empezando desde Gecko 25, una llamada a preventDefault()
del evento keydown
impide la emisión del consiguiente evento keypress
. Este es un comportamiento válido para la especificación D3E y otros navegadores importantes que se comportan de esta misma forma. Por otro lado, Gecko 24 y anteriores emiten el evento keypress
aunque se haya llamado a preventDefault()
del evento keydown
predecesor. Aunque el atributo defaultPrevented
del evento keypress
sea true
en este caso.
Eventos relacionados
Ejemplo
<!DOCTYPE html> <html> <head> <script> 'use strict'; document.addEventListener('keydown', (event) => { const keyName = event.key; alert('keydown event\n\n' + 'key: ' + keyName); }); </script> </head> <body> </body> </html>