Internet Explorer or any Browser F1 keypress displays your own help
I would like to display the user selected help file when pressing F1. This should work on every browser where I test my application. How can I stop the default help file from being display开发者_如何学Ced?
AFAIK, the default action of the F1 key can be changed in any browser except for IE. The Microsoft teams are usually sticklers for maintaining a consistent user experience across their applications and that's why F1 opens help regardless of returning false. That being said, there's a workaround in the form of the window.onhelp event.
// Internet Explorer
if ("onhelp" in window)
window.onhelp = function () {
showMyHelpInsteadOfTheUsualDefaultHelpWindow(true);
return false;
}
// Others
else {
document.onkeydown = function(evt) {
cancelKeypress = (evt.keyCode == 112);
if (cancelKeypress) { // F1 was pressed
showMyHelpInsteadOfTheUsualDefaultHelpWindow(true);
return false;
}
}
// Additional step required for Opera
document.onkeypress = function(evt) {
if (cancelKeypress)
return false;
}
}
"Others" step was adapted from a deleted answer, which was adapted from another answer which, in turn, was adapted from another answer.
Actually, you can cancel the native Help in IE, by setting event.keyCode to 0:
Tested in IE8 & Chrome
<!DOCTYPE html>
<html>
<head>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>
<script type="text/javascript">
$(function () {
var cancelKeypress = false;
// Need to cancel event (only applies to IE)
if ( "onhelp" in window ) {
// (jQuery cannot bind "onhelp" event)
window.onhelp = function () {
return false;
};
}
$(document).keydown(function ( evt ) {
// F1 pressed
if ( evt.keyCode === 112 ) {
if ( window.event ) {
// Write back to IE's event object
window.event.keyCode = 0;
}
cancelKeypress = true;
// Trigger custom help here
alert("My help");
return false;
}
});
// Needed for Opera (as in Andy E's answer)
$(document).keypress(function ( evt ) {
if ( cancelKeypress ) {
cancelKeypress = false; // Only this keypress
return false;
}
});
});
</script>
</head>
<body>
</body>
</html>
加载中,请稍侯......
精彩评论