keydown

问题 I'm working with WPF KeyDown event (KeyEventArgs from Windows.Input). I need to recognize when user pressed F1 alone and Ctrl+F1. private void Window_KeyDown(object sender, KeyEventArgs e) { if (e.Key==Key.F1 && Keyboard.IsKeyDown(Key.LeftCtrl)) { MessageBox.Show("ctrlF1"); } if (e.Key == Key.F1 && !Keyboard.IsKeyDown(Key.LeftCtrl)) { MessageBox.Show("F1"); } } My problem is that when I press Ctrl+F1 plain F1 messagebox would fire too. I tried to add e.Handled to Ctrl+F1 case, but it doesn't

问题 I'm working with WPF KeyDown event (KeyEventArgs from Windows.Input). I need to recognize when user pressed F1 alone and Ctrl+F1. private void Window_KeyDown(object sender, KeyEventArgs e) { if (e.Key==Key.F1 && Keyboard.IsKeyDown(Key.LeftCtrl)) { MessageBox.Show("ctrlF1"); } if (e.Key == Key.F1 && !Keyboard.IsKeyDown(Key.LeftCtrl)) { MessageBox.Show("F1"); } } My problem is that when I press Ctrl+F1 plain F1 messagebox would fire too. I tried to add e.Handled to Ctrl+F1 case, but it doesn't

问题 I'm using jQuery 2. How do I prevent a space being entered in a textbox if it is a leading space (e.g. at the beginning of the string)? I thought this would do it $(document).on("keyup","#s" ,function(evt){ var firstChar = $("#s").val() if(evt.keyCode == 32 && firstChar){ $("#s").val( $("#s").val().trim() ) console.log(" called ") return false; } }) And basically it does but it is a little sloppy. You can see the space being entered and then removed and I was looking for something slightly

问题 I'm working on a MacOS menu bar app which needs to track some global shortcuts in order to facilitate adjusting display brightness on external monitors. However, I cannot get it to fire a handler on any keyboard related events (mouse events work just fine). I'm checking Accessibility with the following code NSDictionary *options = @{CFBridgingRelease(kAXTrustedCheckOptionPrompt): @YES}; BOOL accessibilityEnabled = AXIsProcessTrustedWithOptions((CFDictionaryRef)options); Then, I'm adding a

问题 I'm working on a MacOS menu bar app which needs to track some global shortcuts in order to facilitate adjusting display brightness on external monitors. However, I cannot get it to fire a handler on any keyboard related events (mouse events work just fine). I'm checking Accessibility with the following code NSDictionary *options = @{CFBridgingRelease(kAXTrustedCheckOptionPrompt): @YES}; BOOL accessibilityEnabled = AXIsProcessTrustedWithOptions((CFDictionaryRef)options); Then, I'm adding a

问题 procedure TMainForm.KeyDown(Sender: TObject; var Key: Word; Shift: TShiftState); begin if (GetKeyState(Ord('Q'))<0) and (GetKeyState(Ord('W'))<0) and (GetKeyState(Ord('E'))<0) then ShowMessage('You pressed it'); end; the above event only work if the Focus set to the Main Form. if i run the application and keep pressing Tab and changing the Focus to any control on the Form it will disable this event until we change the Focus again to the main form ? the Question is how i can detect the three

问题 class func addGlobalMonitorForEvents(matching mask: NSEvent.EventTypeMask, handler block: @escaping (NSEvent) -> Void) -> Any?{ print("this inside addGlobalMonitorForEvents") } NSEvent.addGlobalMonitorForEvents(matching: .flagsChanged) { switch $0.modifierFlags.intersection(.deviceIndependentFlagsMask) { case [.shift]: print("shift key is pressed") print("key code is \($0.keyCode))") case [.control] where $0.characters == "1": print("control key is pressed") print("characters is \($0

问题 I am trying to bind the 'CTRL+N' key combination, like this: var ctrlPressed = false; var nCode = 78; var ctrlCode = 224; var cmdCode = 17; document.addEventListener ("keydown", function(e){ if( e.keyCode == ctrlCode || e.keyCode == cmdCode){ ctrlPressed = true; }else{ ctrlPressed = false; } console.log(e.keyCode); }); document.addEventListener ("keyup", function(e){ if(ctrlPressed && e.keyCode == nCode){ e.preventDefault(); nou_element(parent); return; } }); Please note: jQuery isn't

问题 I can understand we would use <input onKeyDown={ ... } /> but what if it is <Modal onKeyDown={ ... } /> because in a way, the keydown event handler code is inside of the Modal class (or function). If the modal is taking the left and right arrow key to perform some specific functions, then I wonder how we would bind the event handler in React, as the key event somehow is related to the modal as a whole, but not to particular input element inside the modal. P.S. I tried outer div and outer

问题 The javascript keypress event is deprecated: https://developer.mozilla.org/en-US/docs/Web/API/Document/keypress_event Some people advise to rely exclusively on the keydown event, eg.: Keydown is the only keyboard event we need https://www.mutuallyhuman.com/blog/2018/03/27/keydown-is-the-only-keyboard-event-we-need/ The problem is that keydown and keypress are not synonymous. Critically, they do not return the same character in many/most cases. Keydown represents which key on the keyboard was