我想在我的小应用程序中捕获关键事件。
我做了什么：
class ViewController : NSViewController {
...
override func keyDown(theEvent: NSEvent) {
if theEvent.keyCode == 124 {
println("abc")
} else {
println("abcd")
}
}
override var acceptsFirstResponder: Bool {
return true
}
override func becomeFirstResponder() -> Bool {
return true
}
override func resignFirstResponder() -> Bool {
return true
}
...
}
怎么了：
按下某个键时，会播放Funk音效。
我看过很多帖子都在谈论这是一个属于NSView的委托，NSViewController没有访问权限。但是keydown函数覆盖自动完成类NSViewController类导致我认为这是错误的。
Xcode 8.2.1•Swift 3.0.2
import Cocoa
class ViewController: NSViewController {
@IBOutlet var textField: NSTextField!
override func viewDidLoad() {
super.viewDidLoad()
NSEvent.addLocalMonitorForEvents(matching: .flagsChanged) {
self.flagsChanged(with: $0)
return $0
}
NSEvent.addLocalMonitorForEvents(matching: .keyDown) {
self.keyDown(with: $0)
return $0
}
}
override func keyDown(with event: NSEvent) {
switch event.modifierFlags.intersection(.deviceIndependentFlagsMask) {
case [.command] where event.characters == "l",[.command,.shift] where event.characters == "l":
print("command-l or command-shift-l")
default:
break
}
textField.stringValue = "key = " + (event.charactersIgnoringModifiers
?? "")
textField.stringValue += "\ncharacter = " + (event.characters ?? "")
}
override func flagsChanged(with event: NSEvent) {
switch event.modifierFlags.intersection(.deviceIndependentFlagsMask) {
case [.shift]:
print("shift key is pressed")
case [.control]:
print("control key is pressed")
case [.option] :
print("option key is pressed")
case [.command]:
print("Command key is pressed")
case [.control,.shift]:
print("control-shift keys are pressed")
case [.option,.shift]:
print("option-shift keys are pressed")
case [.command,.shift]:
print("command-shift keys are pressed")
case [.control,.option]:
print("control-option keys are pressed")
case [.control,.command]:
print("control-command keys are pressed")
case [.option,.command]:
print("option-command keys are pressed")
case [.shift,.control,.option]:
print("shift-control-option keys are pressed")
case [.shift,.command]:
print("shift-control-command keys are pressed")
case [.control,.option,.command]:
print("control-option-command keys are pressed")
case [.shift,.command,.option]:
print("shift-command-option keys are pressed")
case [.shift,.command]:
print("shift-control-option-command keys are pressed")
default:
print("no modifier keys are pressed")
}
}
}
要在按下字符键时摆脱呜呜声，需要对视图进行子类化，重写方法performKeyEquivalent并返回true。
import Cocoa
class View: NSView {
override func performKeyEquivalent(with event: NSEvent) -> Bool {
return true
}
}
Sample Project