I want to position a DIV in a spe开发者_开发技巧cific coordinates ? How can I do that using Javascript ?
Script its left
and top
properties as the number of pixels from the left edge and top edge respectively. It must have position: absolute;
var d = document.getElementById('yourDivId');
d.style.position = "absolute";
d.style.left = x_pos+'px';
d.style.top = y_pos+'px';
Or do it as a function so you can attach it to an event like onmousedown
function placeDiv(x_pos, y_pos) {
var d = document.getElementById('yourDivId');
d.style.position = "absolute";
d.style.left = x_pos+'px';
d.style.top = y_pos+'px';
}
You don't have to use Javascript to do this. Using plain-old css:
div.blah {
position:absolute;
top: 0; /*[wherever you want it]*/
left:0; /*[wherever you want it]*/
}
If you feel you must use javascript, or are trying to do this dynamically Using JQuery, this affects all divs of class "blah":
var blahclass = $('.blah');
blahclass.css('position', 'absolute');
blahclass.css('top', 0); //or wherever you want it
blahclass.css('left', 0); //or wherever you want it
Alternatively, if you must use regular old-javascript you can grab by id
var domElement = document.getElementById('myElement');// don't go to to DOM every time you need it. Instead store in a variable and manipulate.
domElement.style.position = "absolute";
domElement.style.top = 0; //or whatever
domElement.style.left = 0; // or whatever
well it depends if all you want is to position a div and then nothing else, you don't need to use java script for that. You can achieve this by CSS only. What matters is relative to what container you want to position your div, if you want to position it relative to document body then your div must be positioned absolute and its container must not be positioned relatively or absolutely, in that case your div will be positioned relative to the container.
Otherwise with Jquery if you want to position an element relative to document you can use offset() method.
$(".mydiv").offset({ top: 10, left: 30 });
if relative to offset parent position the parent relative or absolute. then use following...
var pos = $('.parent').offset();
var top = pos.top + 'no of pixel you want to give the mydiv from top relative to parent';
var left = pos.left + 'no of pixel you want to give the mydiv from left relative to parent';
$('.mydiv').css({
position:'absolute',
top:top,
left:left
});
Here is a properly described article and also a sample with code. JS coordinates
As per requirement. below is code which is posted at last in that article. Need to call getOffset function and pass html element which returns its top and left values.
function getOffsetSum(elem) {
var top=0, left=0
while(elem) {
top = top + parseInt(elem.offsetTop)
left = left + parseInt(elem.offsetLeft)
elem = elem.offsetParent
}
return {top: top, left: left}
}
function getOffsetRect(elem) {
var box = elem.getBoundingClientRect()
var body = document.body
var docElem = document.documentElement
var scrollTop = window.pageYOffset || docElem.scrollTop || body.scrollTop
var scrollLeft = window.pageXOffset || docElem.scrollLeft || body.scrollLeft
var clientTop = docElem.clientTop || body.clientTop || 0
var clientLeft = docElem.clientLeft || body.clientLeft || 0
var top = box.top + scrollTop - clientTop
var left = box.left + scrollLeft - clientLeft
return { top: Math.round(top), left: Math.round(left) }
}
function getOffset(elem) {
if (elem.getBoundingClientRect) {
return getOffsetRect(elem)
} else {
return getOffsetSum(elem)
}
}
You can also use position fixed css property.
<!-- html code -->
<div class="box" id="myElement"></div>
/* css code */
.box {
position: fixed;
}
// js code
document.getElementById('myElement').style.top = 0; //or whatever
document.getElementById('myElement').style.left = 0; // or whatever
To set the content of a div you can use the following:
document.getElementById(id).style.top = "0px";
document.getElementById(id).style.left = "0px";
Exists other good alternatives in jQuery
I cribbed this and added the 'px'; Works very well.
function getOffset(el) {
el = el.getBoundingClientRect();
return {
left: (el.right + window.scrollX ) +'px',
top: (el.top + window.scrollY ) +'px'
}
}
to call: //Gets it to the right side
el.style.top = getOffset(othis).top ;
el.style.left = getOffset(othis).left ;
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