To the music player to add keydown event to find setTimeout ,

 
The $(document). Keydown (function (e) {

//"write" : volume plus 
If (e.w hich==38) {
SetTimeout (function () {
Var I=music. Volume * 100 
I++ 
If (I & gt; {100} I==100) 
Var I=I/100 
Var v=i.t oFixed (2) 
Music. The volume=v 
}, 100) 
} 
}) 

So with keyup unbundling event look at first, the result of the mistake to write the keydown , surprises incredibly useful, however, what is this principle ah, is really don't understand, you the great god to see

 
The $(document). Keydown (function (e) {
If (e.w hich==38) {$(document). Off (' keydown)} 
}) 

CodePudding user response:

Keydown () is the keyboard press will trigger
Keyup () is the keyboard let go will trigger
One is when press the trigger, a release is triggered when the normal press a button pop-up will soon, unless you grow to have distinction or order difference

CodePudding user response:

I mean, the second piece of code is written keydown ()
Why keydown () to the keydown bound events off () () solution, can trigger the setTimeout ()?
A piece of code before the runtime setTimeout () sets not effect
thank you