在Silverlight中禁用F5

Question

Some of my users accidentally hit F5 when they are typing, and cause them to lose all the stuff they have typed. I do not need to prevent hitting Refresh button.

I tried to use the following javascript, but it only works when the user does not focus on the Silverlight app (ie it works when the user click on somewhere outside of the SL app, but the onkeydown event is not triggered when the user focus on the SL).

document.onkeydown=function(e) {
    var event = window.event || e;
    if (event.keyCode == 116) {
        event.keyCode = 0;
        alert("test");
        return false;
    }
}

Answer 1

Probably the best way of handling this situation would be to use the onbeforeunload event and ask the user for confirmation. This way you can root out the accidental refreshes or closed tabs from the legitimate ones without handling all possible shortcuts.

window.onbeforeunload = function(e) {
    return 'Are you sure you want to leave without saving your changes?';
};

You could even display the confirmation dialog only if there are some unsaved changes.

Answer 2

I'd say, something like this?

document.onkeydown = function() 
{
    switch (event.keyCode) 
    {
        case 116 : //F5 button
            event.returnValue = false;
            event.keyCode = 0;
            return false;
        case 82 : //R button
            if (event.ctrlKey) 
            {
                event.returnValue = false;
                event.keyCode = 0;
                return false;
            }
    }
}

note: ctrl + r is a shortcut to refresh as well