问题
I have following javascript to prevent user from entering invalid characters into a text field. It's working well in chrome but not in firefox. It's preventing the backspace key to be entered in the text field in firefox.
function onlyNumbers(evt) {
var theEvent = evt || window.event;
var key = theEvent.keyCode || theEvent.which;
key = String.fromCharCode( key );
var regex = /[0-9]|\./;
if( !regex.test(key) ) {
theEvent.returnValue = false;
if(theEvent.preventDefault) theEvent.preventDefault();
}
}
Can anyone please have a look and propose a fix for firefox to not prevent backspace key to act on a text field ?
Probably I guess, adding the regex for the backspace character would do the job here. Does anyone know, how to add the regex for matching the backspace
Edit:
Also, the above code has supposed to interrupted with the Tab key behaviour, I am not able to jump to next fields in the form using Tab key.
回答1:
see http://jsfiddle.net/8ZJZD/1/
var el=document.getElementById('cnfMobileNo');
el.onkeydown=function onlyNumbers(evt) {
var theEvent = evt || window.event;
var key = theEvent.keyCode || theEvent.which;
if(key===8){return;}
key = String.fromCharCode(key);
var regex = /[0-9]|\./;
if( !regex.test(key) ) {
theEvent.returnValue = false;
if(theEvent.preventDefault) theEvent.preventDefault();
}
}
Just use if(key===8){return;}
Edit:
If you want to exclude more keys, use
var el=document.getElementById('cnfMobileNo');
el.onkeydown=function onlyNumbers(evt) {
var theEvent = evt || window.event,
key = theEvent.keyCode || theEvent.which,
exclusions=[8,9]; /*Add exceptions here */
if(exclusions.indexOf(key)>-1){return;}
key = String.fromCharCode(key);
var regex = /[0-9]|\./;
if( !regex.test(key) ) {
theEvent.returnValue = false;
if(theEvent.preventDefault) theEvent.preventDefault();
}
}
See it here: http://jsfiddle.net/8ZJZD/2/
You can know the keyCode
of each key using alert(key)
(before key = String.fromCharCode(key)
).
You could also exclude
- The arrow keys: 37,38,39,40
- Enter: 13
- Context menu: 93
- Start and End: 36,35
回答2:
Im not sure of the backspace regex but this should work too
$("#myInput").bind('keyup', function(){
val1 = $(this).val();
$(this).val(val1.replace(/[^0-9.]/g,''));
});
You might do away with bind and directly attach keyup
Fiddle - jsfiddle
来源:https://stackoverflow.com/questions/12236721/js-disabling-backspace-functionality-in-firefox