When a user gives focus on an View like an
Both the
Handling Single Key Events
To handle an individual key press, implement
Below is just s glimpse of some keys you see the full list of keycode List of Key Code
here's the
EditText
element and the user has a hardware keyboard attached, all
input is handled by the system. If, however, you'd like to intercept
or directly handle the keyboard input yourself, you can do so by implementing callback methods
from the KeyEvent.Callback interface, such as onKeyDown() and onKeyMultiple().Both the
Activity and View class implement the
KeyEvent.Callback interface, so you
should generally override the callback methods in your extension of these classes as
appropriate.Handling Single Key Events
To handle an individual key press, implement
onKeyDown() or onKeyUp() as appropriate. Usually, we should
use onKeyUp() if you want to be sure that you receive
only one event. If the user presses and holds the button, then onKeyDown() is called multiple times.Below is just s glimpse of some keys you see the full list of keycode List of Key Code
@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
switch (keyCode) {
case KeyEvent.KEYCODE_D:
// Your code to handle event when 'D' is pressed
return true;
case KeyEvent.KEYCODE_F: // Your code to handle event when 'F' is pressed
return true;
case KeyEvent.KEYCODE_J:
// Your code to handle event when 'J' is pressed
return true;
case KeyEvent.KEYCODE_K:
// Your code to handle event when 'K' is pressed
return true;
default:
return super.onKeyUp(keyCode, event);
}
}
Handling Modifier keys like Shift, Control
To respond to modifier key events such as when a key is combined with Shift or Control, you can
query the KeyEvent that's passed to the callback method. Several methods
provide information about modifier keys such as getModifiers()
and getMetaState(). However, the simplest solution is to check whether
the exact modifier key you care about is being pressed with methods such as
isShiftPressed() and isCtrlPressed().Example:
here's the
onKeyDown() implementation
again, with some extra handling for when the Shift key is held down with one of the keys:@Override
public boolean onKeyUp(int keyCode, KeyEvent event) {
switch (keyCode) {
...
case KeyEvent.KEYCODE_J:
if (event.isShiftPressed()) {
// Your Code
} else {
// Your Code
}
return true;
case KeyEvent.KEYCODE_K:
if (event.isShiftPressed()) {
// Your Code
} else {
// Your Code
}
return true;
}
default:
return super.onKeyUp(keyCode, event);
}
