keydown

I have a magnetic card reader that uses the keyboard input to send data. I am using a KeyDown event where I get this object (C# WPF): KeyEventArgs e I want to take the keys that I get and make them one string. I tried to concat e.Key.ToString() , but that doesn't work. My input has lots of numbers and signs (such as ; ? = etc.), and the e.Key.ToString() thing doesn't work (it gives me D3 for a number, and SHIFT or CTRL + another key for the signs). I just want the string, so when I use for example Console.WriteLine I will get something like ;51895401051=000001341? and not

I'm attempting to do info validation against user text input in the process of keydown event. The reason that I am trying to validate in the keydown event is because I do not want to display the characters those that are considered to be illegal in the input box at the beginning. The validation I am writing is like this, function validateUserInput(){ var code = this.event.keyCode; if ((code<48||code>57) // numerical &&code!==46 //delete &&code!==8 //back space &&code!==37 // <- arrow &&code!==39) // -> arrow { this.event.preventDefault(); } } I can keep going like this, however I am seeing

In xcode last version, I am trying to get the keyDown event of an NSTextField. However, despite following multiple tutorials on the internet (delegates, controllers...), I still can't receive it. Any easy hint for me ? Thanks ! Scott Jenkins I got sick of all the non answers to do it some other way people so I put my nose down and figured out a way to make this work. This isn't using keydown event directly but it is using the keydown in the block. And the behavior is exactly what I wanted. Subclass the text field .h @interface LQRestrictedInputTextField : NSTextField .m In the become first

Good morning everybody! I have a case, when I should prevent users to entering space as a first character on input field. I have a demo here: http://jsbin.com/foyetolo/2/edit It works only when you hit spacebar for first time. When you start typing other characters and select whole text in input (ctrl+a) and then hit the space bar it adds the space in the beginning of input field. So, how to check if on keypress/keydown if the first character will be a space, return false and not allow it to type the space as a first character? You can do this by checking if key is space and selection start is

How can I set an event handler (such as keydown ) to entire solution, not a single window? Register a global event handler in your application class (App.cs), like this: public partial class App : Application { protected override void OnStartup(StartupEventArgs e) { base.OnStartup(e); EventManager.RegisterClassHandler(typeof(Window), Window.KeyDownEvent, new RoutedEventHandler(Window_KeyDown)); } void Window_KeyDown(object sender, RoutedEventArgs e) { // your code here } } This will handle the KeyDown event for any Window in your app. You can cast e to KeyEventArgs to get to the information

Can I know the number of keys pressed at the same time in Javascript? If so, how can I have an array of their keyCode ? You can listen for keydown and keyup events. var keys = { length: 0 }; document.onkeydown = function(e){ if(!keys[e.keyCode]) { keys[e.keyCode] = true; keys.length++; } } document.onkeyup = function(e){ if(keys[e.keyCode]) { keys[e.keyCode] = false; keys.length--; } } Then all the keys that are true are the ones that are pressed currently. Fiddle demo thanks to @Esailija: http://jsfiddle.net/maniator/Gc54D/ This should do the trick. It is similar to Neal's, but should fix a