Using event.which to verify if the user pressed the spacebar doesn't work in Firefox

问题

I want a script to verify if the key pressed is 'spacebar', keycode 32. I noticed that IE uses other function names.

I tried a lot of solutions found here and this:

event = event || window.event // IE does not pass event to the function
if(event == window.event){
    code = event.keyCode;
}else{
    code = event.which;
} 
if(code == '32') {}

But it still didn't work in Firefox.

I think I'm calling the function wrongly in Firefox. Look at the entire script:

<textarea onkeydown="predicao(this);" cols="40" rows="10" id="test" onfocus="this.focus()"></textarea>
<input id="example" style="display: none;" onkeydown="javascript: insert(this);"/>

<script language="Javascript">
<!--

function predicao(objeto){
    comprimento = objeto.value.length;
    var antipenultimo = comprimento - 4;
    var input = objeto.value.substring(antipenultimo,comprimento);
    var output = "";
    for(i=0; i<input.length; ++i){
        if(output != "") output += ", ";
        output += input.charCodeAt(i);
    }
    if (output == "91, 91, 103, 32"){

        var preditor = document.getElementById('example');
        preditor.value = '';
        preditor.style.display = 'block';
        preditor.focus();
        preditor.select();
    }  
}
function insert(objeto){
event = event.which || window.event // IE does not pass event to the function
if(event == window.event){
    code = event.keyCode;
}else{
    code = event.charCode;
} 
    if(keynum == '32') {
        var texto = document.getElementById('test').value;
        texto += objeto.value+']]';
        $('#test').focus();
        document.getElementById('test').value = texto;
        objeto.style.display = 'none';
    }
}
$(document).ready(function(){
    var data = "Ab Aco Ado Ala Mano Cata Ca Obo Olo Po Poq".split(" ");
$("#example").autocomplete(data);});
</script>

What I'm trying to do is - (I don't know the name) - a Prediction Help Inputter inside a textarea. It uses jQuery autocomplete. When the user types '[[g ' inside textarea (id=test), a input with autocomplete is opened (id=example), so it search in 'data'. When the user find the desired data, he must press spacebar to insert the data into the textarea, closing with ']]' But it doesn't work in Firefox.

(And yes, I'm using JavaScript and jQuery to same elements in a totally wrong way because I'm not too good at this, I'll try to correct it after Firefox works.)

回答1:

EDIT

HMTL:

<textarea onkeydown="predicao(this);" cols="40" rows="10" id="test" onfocus="this.focus()"></textarea>
<input id="example" style="display: none;" onkeydown="insert(this, event);"/>

JS:

function predicao(objeto){
    var comprimento = objeto.value.length;
    var antipenultimo = comprimento - 4;
    var input = objeto.value.substring(antipenultimo,comprimento);
    var output = "";
    for(var i=0; i<input.length; ++i){
        if(output != "") output += ", ";
        output += input.charCodeAt(i);
    }
    if (output == "91, 91, 103, 32"){
        var preditor = document.getElementById('example');
        preditor.value = '';
        preditor.style.display = 'block';
        preditor.focus();
        preditor.select();
    }
}
function insert(objeto, evt){
    var e = evt || event;
    var code = e.keyCode || e.which;
    if(code == '32') {
        var texto = document.getElementById('test').value;
        texto += objeto.value+']]';
        $('#test').focus();
        document.getElementById('test').value = texto;
        objeto.style.display = 'none';
    }
}
$(document).ready(function(){
    var data = "Ab Aco Ado Ala Mano Cata Ca Obo Olo Po Poq".split(" ");
$("#example").autocomplete(data);});

I used here what Alexander Kahoun and pimvdb have posted.

回答2:

I've never had any problems with the following and I've used it in IE6 through IE9, Firefox 3.5-5 and Chrome from at least 9-13

function captureSpace (evt) {
    var e = evt || event;
    var code = e.keyCode || e.which;
    if (code === 32) {
        // Do your thing...
    }
}

This uses a logical OR to basically say if evt is a falsy value then use the window.event

var e = evt || event;

This uses a logical OR to assign the code for the key pressed in the same way

var code = e.keyCode || e.which;

This gives you a true or false value if the code is exactly equal to the integer value of 32

(code === 32)

I also suggest that you assign this to the key UP event.

回答3:

In principle the way you do it should work. Check this out:

<html>
<head>
<script type="text/javascript">
function check(e){
 var keynum
 if(window.event)
 {
  keynum = e.keyCode
 }
 else if(e.which)
 {
  keynum = e.which
 }
 if(keynum=='32')
 {
  alert(keynum);}
  }
</script>
</head>
<form>
<input type="text" onkeypress="check(event)" />
</form>
</body>
</html>

It seems that your lack of response is context dependent.

回答4:

To display unicode of key pressed

         <script type="text/javascript">
                function displayunicode(e){
                                            var unicode=e.keyCode? e.keyCode : e.charCode;
                                            alert(unicode);
                                          }
        </script>
                <form>
                      <input type="text" size="2" maxlength="1" onkeyup="displayunicode(event); this.select()" />
                </form>

Determining which key was pressed

来源：https://stackoverflow.com/questions/7051112/using-event-which-to-verify-if-the-user-pressed-the-spacebar-doesnt-work-in-fir

标签

javascript

firefox

keycode