单击按钮后将Var更改为0

Question

In my javascript I have an autoscroll wich is set to var speed 1. I want to set the var spped to 0 when there is clicked on a button. Somebody out there who can help me?

Button:

<button name="NONAUTO"  value="">Turn off Autoscroll</button>

Here's my Javascript:

var speed=1;
var currentpos=0,alt=1,curpos1=0,curpos2=-1;

function initialize(){
    startit();
}

function scrollwindow(){
    if (document.all && !document.getElementById)
        temp=document.body.scrollTop;
    else
        temp=window.pageYOffset;

    if (alt==0)
        alt=0;
    else
        alt=0;

    if (alt==0)
        curpos1=temp;
    else
        curpos2=temp;

    if (curpos1!=curpos2){

        if (document.all)
            currentpos=document.body.scrollTop+speed;
        else
            currentpos=window.pageYOffset+speed;

        window.scroll(0,currentpos);
    } 
    else {
        currentpos=0;
        window.scroll(0,currentpos);
    }
}

function startit(){
    setInterval("scrollwindow()",50);
}

window.onload=initialize;

The autoscroll is interruptable, you can free scroll but if you can fix if you scroll and wait like 20 seconds and thenproceed the autoscroll that would be great!But this is just an extra.

Answer 1

Add an onclick attribute to the button like onclick = change() .

And, you can make the following change() function :

function change(){ start = 0;}

You can also add onclick event listener by document.getElementsByName("NONAUTO")[0].addEventListener("click",change,false)

Answer 2

you can do it like this.

 <button onClick = "turnOff(event)" name="NONAUTO"  value="">Turn off Autoscroll</button>

in the script file add this function.

var turnOff = function(event)
{
  event.preventDefault();
  speed = 0;
  alert(speed);
}

Answer 3

If you are using jQuery you could use:

<button id="buttId" name="NONAUTO"  value="">Turn off Autoscroll</button>
$( "#buttId" ).click( function()
{
  speed = 0;
}

or if you don't want to add an ID attribute:

$( "[name='NONAUTO']" ).click( function()
{
  speed = 0;
}

Answer 4

To do this, you need to use Event Handlers in JavaScript . You specifically need to handle the Click event of the particular button . You can do this in the html code itself like other have mentioned. This is called Obtrusive JavaScript . It is generally recommended to use Unobtrusive JavaScript . Here's one way you can do it using the Event Listeners :

 window.onload = function() { var speed = 1; var button = document.getElementById("nonAuto"); button.addEventListener("click", function() { speed = 0; alert(speed); }); }; 

 <button name="NONAUTO" id="nonAuto" value="">Turn off Autoscroll</button> 

You can also toggle the autoscroll value in this way :

 window.onload = function() { var speed = 1; var button = document.getElementById("nonAuto"); button.addEventListener("click", function() { if (speed === 1) { speed = 0; button.firstChild.data = "Turn on AutoScroll"; alert(speed); } else { speed = 1; button.firstChild.data = "Turn off AutoScroll"; alert(speed); } }); }; 

 <button name="NONAUTO" id="nonAuto" value="">Turn off Autoscroll</button> 

Hope this helps!!!

Answer 5

You want to change the variable speed, from 1 to 0 when a button is clicked. Simply just write this in your html file:

<button onClick:'var speed = 0'></button>