how to disable the function of ESC key in JavaScript?

问题

In my chat application there are some text fields which gets the user login details.

when filling the user details,If user suddenly pressed the ESC key,the data will be lost.

I need to disable the function of ESC key ? which event I need to use ? how can I do that.

my Java Script code is ,

function esc(e){
    e = e || window.event || {};
    var charCode = e.charCode || e.keyCode || e.which;
    if(charCode == 27){
    return false;
    }
}

Searched a lot in Stack overflow and google.Nothing worked.Please any one help me to do that . Thanks..

回答1:

You can bind an eventlistener to your input field to catch the Event when Esc is pressed and supress it.

document.querySelector("input").addEventListener("keydown",function(e){
    var charCode = e.charCode || e.keyCode || e.which;
    if (charCode == 27){
         alert("Escape is not allowed!");
        return false;
    }
});

Example

回答2:

I got the solution to control the " F5 , Esc , BackSpace(BS) " keys with the following code.

My Java Script code will be ,

document.attachEvent("onkeydown", win_onkeydown_handler);

function win_onkeydown_handler() {
    switch (event.keyCode) {

    case 116 : // 'F5'
         event.returnValue = false;
         event.keyCode = 0;
         break;  

    case 27: // 'Esc'
        event.returnValue = false;
        event.keyCode = 0;
        break;

    case 08: // 'BackSpace'
        if (event.srcElement.tagName == "INPUT"
                || event.srcElement.tagName == "TEXTAREA") {
        } else {
            event.returnValue = false;
            event.keyCode = 0;
        }
        break;

    }
}

Thanks who are all supported me to do this and for your suggestions.

回答3:

I have used this for a login popup code:

jQuery(document).keyup(function(e){
    if(e.keyCode==27 && popupStatus==1){
    // alert('not allowed !!!');
        // or any other code
     return false;
    }
});

回答4:

I have done something similar using jquery to limit entry to numbers

    $(inputBox).keydown(function(event) {
        // Allow only backspace and delete
        var allowed_keys = [
            46, // delete
            8, // backspace
                 ];
        if ($.inArray(event.keyCode, allowed_keys) != -1) {
            // let it happen, don't do anything
        }
        else {
            // Ensure that it is a number and stop the keypress
            if (event.keyCode < 48 || event.keyCode > 57 ) {
                event.preventDefault(); 
            }   
        }
    });

来源：https://stackoverflow.com/questions/14601616/how-to-disable-the-function-of-esc-key-in-javascript

标签

javascript

javascript-events