javascript - detect ctrl key pressed or up, keypress event doesn't trigger

Question

I see some similar questions here (like JavaScript: Check if CTRL button was pressed) but my problem is actually the event triggering. My js code:

    // Lis         


        

Answer 1

Your event has a property named ctrlKey. You can check this to look if the key was pressed or not. See snippet below for more control like keys.

function detectspecialkeys(e){
    var evtobj=window.event? event : e
    if (evtobj.altKey || evtobj.ctrlKey || evtobj.shiftKey)
        alert("you pressed one of the 'Alt', 'Ctrl', or 'Shift' keys")
}
document.onkeypress=detectspecialkeys

Answer 2

Using onkeydown rather than onkeypress may help.

From http://www.w3schools.com/jsref/event_onkeypress.asp

Note: The onkeypress event is not fired for all keys (e.g. ALT, CTRL, SHIFT, ESC) in all browsers. To detect only whether the user has pressed a key, use the onkeydown event instead, because it works for all keys.

Answer 3

Try using if (e.ctrlKey).

MDN: event.ctrlKey