KeyEvent Class

Reference

Definition

Namespace:: Android.Views

Assembly:: Mono.Android.dll

Important

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Object used to report key and button events.

[Android.Runtime.Register("android/view/KeyEvent", DoNotGenerateAcw=true)]
public class KeyEvent : Android.Views.InputEvent, IDisposable, Java.Interop.IJavaPeerable

[<Android.Runtime.Register("android/view/KeyEvent", DoNotGenerateAcw=true)>]
type KeyEvent = class
    inherit InputEvent
    interface IParcelable
    interface IJavaObject
    interface IDisposable
    interface IJavaPeerable

Inheritance: Object

Object

InputEvent
KeyEvent

Attributes: RegisterAttribute

Implements: IParcelable IJavaObject IJavaPeerable IDisposable

Remarks

Object used to report key and button events.

Each key press is described by a sequence of key events. A key press starts with a key event with #ACTION_DOWN. If the key is held sufficiently long that it repeats, then the initial down is followed additional key events with #ACTION_DOWN and a non-zero value for #getRepeatCount(). The last key event is a #ACTION_UP for the key up. If the key press is canceled, the key up event will have the #FLAG_CANCELED flag set.

Key events are generally accompanied by a key code (#getKeyCode()), scan code (#getScanCode()) and meta state (#getMetaState()). Key code constants are defined in this class. Scan code constants are raw device-specific codes obtained from the OS and so are not generally meaningful to applications unless interpreted using the KeyCharacterMap. Meta states describe the pressed state of key modifiers such as #META_SHIFT_ON or #META_ALT_ON.

Key codes typically correspond one-to-one with individual keys on an input device. Many keys and key combinations serve quite different functions on different input devices so care must be taken when interpreting them. Always use the KeyCharacterMap associated with the input device when mapping keys to characters. Be aware that there may be multiple key input devices active at the same time and each will have its own key character map.

As soft input methods can use multiple and inventive ways of inputting text, there is no guarantee that any key press on a soft keyboard will generate a key event: this is left to the IME's discretion, and in fact sending such events is discouraged. You should never rely on receiving KeyEvents for any key on a soft input method. In particular, the default software keyboard will never send any key event to any application targetting Jelly Bean or later, and will only send events for some presses of the delete and return keys to applications targetting Ice Cream Sandwich or earlier. Be aware that other software input methods may never send key events regardless of the version. Consider using editor actions like android.view.inputmethod.EditorInfo#IME_ACTION_DONE if you need specific interaction with the software keyboard, as it gives more visibility to the user as to how your application will react to key presses.

When interacting with an IME, the framework may deliver key events with the special action #ACTION_MULTIPLE that either specifies that single repeated key code or a sequence of characters to insert.

In general, the framework cannot guarantee that the key events it delivers to a view always constitute complete key sequences since some events may be dropped or modified by containing views before they are delivered. The view implementation should be prepared to handle #FLAG_CANCELED and should tolerate anomalous situations such as receiving a new #ACTION_DOWN without first having received an #ACTION_UP for the prior key press.

Refer to InputDevice for more information about how different kinds of input devices and sources represent keys and buttons.

Java documentation for android.view.KeyEvent.

Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2.5 Attribution License.

Constructors

KeyEvent(Int64, Int64, KeyEventActions, Keycode, Int32, MetaKeyStates, Int32, Int32, KeyEventFlags, InputSourceType)	Create a new key event.
KeyEvent(Int64, Int64, KeyEventActions, Keycode, Int32, MetaKeyStates, Int32, Int32, KeyEventFlags)	Create a new key event.
KeyEvent(Int64, Int64, KeyEventActions, Keycode, Int32, MetaKeyStates, Int32, Int32)	Create a new key event.
KeyEvent(Int64, Int64, KeyEventActions, Keycode, Int32, MetaKeyStates)	Create a new key event.
KeyEvent(Int64, Int64, KeyEventActions, Keycode, Int32)	Create a new key event.
KeyEvent(Int64, String, Int32, KeyEventFlags)	Create a new key event for a string of characters.
KeyEvent(IntPtr, JniHandleOwnership)	A constructor used when creating managed representations of JNI objects; called by the runtime.
KeyEvent(KeyEvent, Int64, Int32)	Obsolete. Copy an existing key event, modifying its time and repeat count.
KeyEvent(KeyEvent)	Make an exact copy of an existing key event.
KeyEvent(KeyEventActions, Keycode)	Create a new key event.

Fields

KeycodeDemoApp1	Obsolete. Key code constant: Demo Application key #1.
KeycodeDemoApp2	Obsolete. Key code constant: Demo Application key #2.
KeycodeDemoApp3	Obsolete. Key code constant: Demo Application key #3.
KeycodeDemoApp4	Obsolete. Key code constant: Demo Application key #4.
KeycodeFeaturedApp1	Obsolete. Key code constant: Featured Application key #1.
KeycodeFeaturedApp2	Obsolete. Key code constant: Featured Application key #2.
KeycodeFeaturedApp3	Obsolete. Key code constant: Featured Application key #3.
KeycodeFeaturedApp4	Obsolete. Key code constant: Featured Application key #4.
KeycodeKeyboardBacklightDown	Obsolete. Key code constant: Keyboard backlight down
KeycodeKeyboardBacklightToggle	Obsolete. Key code constant: Keyboard backlight toggle
KeycodeKeyboardBacklightUp	Obsolete. Key code constant: Keyboard backlight up
KeycodeMacro1	Obsolete. Key code constant: A button whose usage can be customized by the user through the system.
KeycodeMacro2	Obsolete. Key code constant: A button whose usage can be customized by the user through the system.
KeycodeMacro3	Obsolete. Key code constant: A button whose usage can be customized by the user through the system.
KeycodeMacro4	Obsolete. Key code constant: A button whose usage can be customized by the user through the system.
KeycodeRecentApps	Obsolete. Key code constant: To open recent apps view (a.
KeycodeStylusButtonPrimary	Obsolete. Key code constant: The primary button on the barrel of a stylus.
KeycodeStylusButtonSecondary	Obsolete. Key code constant: The secondary button on the barrel of a stylus.
KeycodeStylusButtonTail	Obsolete. Key code constant: A button on the tail end of a stylus.
KeycodeStylusButtonTertiary	Obsolete. Key code constant: The tertiary button on the barrel of a stylus.
KeycodeVideoApp1	Obsolete. Key code constant: Video Application key #1.
KeycodeVideoApp2	Obsolete. Key code constant: Video Application key #2.
KeycodeVideoApp3	Obsolete. Key code constant: Video Application key #3.
KeycodeVideoApp4	Obsolete. Key code constant: Video Application key #4.
KeycodeVideoApp5	Obsolete. Key code constant: Video Application key #5.
KeycodeVideoApp6	Obsolete. Key code constant: Video Application key #6.
KeycodeVideoApp7	Obsolete. Key code constant: Video Application key #7.
KeycodeVideoApp8	Obsolete. Key code constant: Video Application key #8.
MaxKeycode	Obsolete. This member is deprecated.

Properties

Action	Retrieve the action of this key event.
Characters	For the special case of a `#ACTION_MULTIPLE` event with key code of `#KEYCODE_UNKNOWN`, this is a raw string of characters associated with the event.
Class	Returns the runtime class of this `Object`. (Inherited from Object)
Creator
Device	Gets the device that this event came from. (Inherited from InputEvent)
DeviceId	To be added
DisplayLabel	Gets the primary character for this key.
DownTime	Retrieve the time of the most recent key down event, in the `android.os.SystemClock#uptimeMillis` time base.
EventTime	Retrieve the time this event occurred, in the `android.os.SystemClock#uptimeMillis` time base.
Flags	Returns the flags for this key event.
Handle	The handle to the underlying Android instance. (Inherited from Object)
HasNoModifiers	Returns true if no modifier keys are pressed.
IsAltPressed	Returns the pressed state of the ALT meta key.
IsCanceled	For `#ACTION_UP` events, indicates that the event has been canceled as per `#FLAG_CANCELED`.
IsCapsLockOn	Returns the locked state of the CAPS LOCK meta key.
IsCtrlPressed	Returns the pressed state of the CTRL meta key.
IsFunctionPressed	Returns the pressed state of the FUNCTION meta key.
IsLongPress	For `#ACTION_DOWN` events, indicates that the event has been canceled as per `#FLAG_LONG_PRESS`.
IsMetaPressed	Returns the pressed state of the META meta key.
IsNumLockOn	Returns the locked state of the NUM LOCK meta key.
IsPrintingKey	Returns true if this key produces a glyph.
IsScrollLockOn	Returns the locked state of the SCROLL LOCK meta key.
IsShiftPressed	Returns the pressed state of the SHIFT meta key.
IsSymPressed	Returns the pressed state of the SYM meta key.
IsSystem	Is this a system key? System keys can not be used for menu shortcuts.
IsTracking	For `#ACTION_UP` events, indicates that the event is still being tracked from its initial down event as per `#FLAG_TRACKING`.
JniIdentityHashCode	(Inherited from Object)
JniPeerMembers
KeyCharacterMap	Gets the `KeyCharacterMap` associated with the keyboard device.
KeyCode	Retrieve the key code of the key event.
MaxKeyCode	Returns the maximum keycode.
MetaState	Returns the state of the meta keys.
ModifierMetaStateMask	Gets a mask that includes all valid modifier key meta state bits.
Modifiers	Returns the state of the modifier keys.
Number	Gets the number or symbol associated with the key.
PeerReference	(Inherited from Object)
RepeatCount	Retrieve the repeat count of the event.
ScanCode	Retrieve the hardware key id of this key event.
Source	To be added
ThresholdClass	This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.
ThresholdType	This API supports the Mono for Android infrastructure and is not intended to be used directly from your code.
UnicodeChar	Gets the Unicode character generated by the specified key and meta key state combination.

Methods

ChangeAction(KeyEvent, KeyEventActions)	Create a new key event that is the same as the given one, but whose action is replaced with the given value.
ChangeFlags(KeyEvent, KeyEventFlags)	Create a new key event that is the same as the given one, but whose flags are replaced with the given value.
ChangeTimeRepeat(KeyEvent, Int64, Int32, KeyEventFlags)	Create a new key event that is the same as the given one, but whose event time and repeat count are replaced with the given value.
ChangeTimeRepeat(KeyEvent, Int64, Int32)	Create a new key event that is the same as the given one, but whose event time and repeat count are replaced with the given value.
Clone()	Creates and returns a copy of this object. (Inherited from Object)
DescribeContents()	Describe the kinds of special objects contained in this Parcelable's marshalled representation. (Inherited from InputEvent)
Dispatch(KeyEvent+ICallback, KeyEvent+DispatcherState, Object)	Deliver this key event to a KeyEvent Callback interface.
Dispatch(KeyEvent+ICallback)
Dispose()	(Inherited from Object)
Dispose(Boolean)	(Inherited from Object)
Equals(Object)	Indicates whether some other object is "equal to" this one. (Inherited from Object)
GetDeadChar(Int32, Int32)	Get the character that is produced by putting accent on the character c.
GetHashCode()	Returns a hash code value for the object. (Inherited from Object)
GetKeyData(KeyCharacterMap+KeyData)	Obsolete. Get the character conversion data for a given key code.
GetMatch(Char[], Int32)
GetMatch(Char[], MetaKeyStates)	Gets the first character in the character array that can be generated by the specified key code.
GetMatch(Char[])	Gets the first character in the character array that can be generated by the specified key code.
GetUnicodeChar(Int32)
GetUnicodeChar(MetaKeyStates)	Gets the Unicode character generated by the specified key and meta key state combination.
HasModifiers(MetaKeyStates)	Returns true if only the specified modifiers keys are pressed.
IsFromSource(InputSourceType)	Determines whether the event is from the given source. (Inherited from InputEvent)
IsGamepadButton(Keycode)	Returns true if the specified keycode is a gamepad button.
IsMediaSessionKey(Int32)	Returns whether this key will be sent to the `android.media.session.MediaSession.Callback` if not handled.
IsModifierKey(Keycode)	Returns true if this key code is a modifier key.
JavaFinalize()	Called by the garbage collector on an object when garbage collection determines that there are no more references to the object. (Inherited from Object)
KeyCodeFromString(String)	Gets a keycode by its symbolic name such as "KEYCODE_A" or an equivalent numeric constant such as "29".
KeyCodeToString(Keycode)	Returns a string that represents the symbolic name of the specified keycode such as "KEYCODE_A", "KEYCODE_DPAD_UP", or an equivalent numeric constant such as "1001" if unknown.
MetaStateHasModifiers(MetaKeyStates, MetaKeyStates)	Returns true if only the specified modifier keys are pressed according to the specified meta state.
MetaStateHasNoModifiers(MetaKeyStates)	Returns true if no modifiers keys are pressed according to the specified meta state.
NormalizeMetaState(MetaKeyStates)	Normalizes the specified meta state.
Notify()	Wakes up a single thread that is waiting on this object's monitor. (Inherited from Object)
NotifyAll()	Wakes up all threads that are waiting on this object's monitor. (Inherited from Object)
SetHandle(IntPtr, JniHandleOwnership)	Sets the Handle property. (Inherited from Object)
SetSource(InputSourceType)	To be added
StartTracking()	Call this during `Callback#onKeyDown` to have the system track the key through its final up (possibly including a long press).
ToArray<T>()	(Inherited from Object)
ToString()	Returns a string representation of the object. (Inherited from Object)
UnregisterFromRuntime()	(Inherited from Object)
Wait()	Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>. (Inherited from Object)
Wait(Int64, Int32)	Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object)
Wait(Int64)	Causes the current thread to wait until it is awakened, typically by being <em>notified</em> or <em>interrupted</em>, or until a certain amount of real time has elapsed. (Inherited from Object)
WriteToParcel(Parcel, ParcelableWriteFlags)	Flatten this object in to a Parcel.

Explicit Interface Implementations

IJavaPeerable.Disposed()	(Inherited from Object)
IJavaPeerable.DisposeUnlessReferenced()	(Inherited from Object)
IJavaPeerable.Finalized()	(Inherited from Object)
IJavaPeerable.JniManagedPeerState	(Inherited from Object)
IJavaPeerable.SetJniIdentityHashCode(Int32)	(Inherited from Object)
IJavaPeerable.SetJniManagedPeerState(JniManagedPeerStates)	(Inherited from Object)
IJavaPeerable.SetPeerReference(JniObjectReference)	(Inherited from Object)

Extension Methods

JavaCast<TResult>(IJavaObject)	Performs an Android runtime-checked type conversion.
JavaCast<TResult>(IJavaObject)
GetJniTypeName(IJavaPeerable)

Applies to

通过