我正在创建一个jQuery插件。
我如何得到真实的图像宽度和高度与Javascript在Safari?
Firefox 3、IE7和Opera 9的操作如下:
var pic = $("img")
// need to remove these in of case img-element has set width and height
pic.removeAttr("width");
pic.removeAttr("height");
var pic_real_width = pic.width();
var pic_real_height = pic.height();
但在Safari和谷歌等Webkit浏览器中，Chrome的值为0。
当前回答
Jquery有两个属性叫做naturalWidth和naturalHeight，你可以这样使用。
$('.my-img')[0].naturalWidth
$('.my-img')[0].naturalHeight
其中my-img是一个类名，用于选择我的图像。
其他回答
我们如何在不眨眼的情况下获得正确的真实尺寸:
(function( $ ){
$.fn.getDimensions=function(){
alert("First example:This works only for HTML code without CSS width/height definition.");
w=$(this, 'img')[0].width;
h=$(this, 'img')[0].height;
alert("This is a width/height on your monitor: " + $(this, 'img')[0].width+"/"+$(this, 'img')[0].height);
//This is bad practice - it shows on your monitor
$(this, 'img')[0].removeAttribute( "width" );
$(this, 'img')[0].removeAttribute( "height" );
alert("This is a bad effect of view after attributes removing, but we get right dimensions: "+ $(this, 'img')[0].width+"/"+$(this, 'img')[0].height);
//I'am going to repare it
$(this, 'img')[0].width=w;
$(this, 'img')[0].height=h;
//This is a good practice - it doesn't show on your monitor
ku=$(this, 'img').clone(); //We will work with a clone
ku.attr( "id","mnbv1lk87jhy0utrd" );//Markup clone for a final removing
ku[0].removeAttribute( "width" );
ku[0].removeAttribute( "height" );
//Now we still get 0
alert("There are still 0 before a clone appending to document: "+ $(ku)[0].width+"/"+$(ku)[0].height);
//Hide a clone
ku.css({"visibility" : "hidden",'position':'absolute','left':'-9999px'});
//A clone appending
$(document.body).append (ku[0]);
alert("We get right dimensions: "+ $(ku)[0].width+"/"+$(ku)[0].height);
//Remove a clone
$("#mnbv1lk87jhy0utrd").remove();
//But a next resolution is the best of all. It works in case of CSS definition of dimensions as well.
alert("But if you want to read real dimensions for image with CSS class definition outside of img element, you can't do it with a clone of image. Clone method is working with CSS dimensions, a clone has dimensions as well as in CSS class. That's why you have to work with a new img element.");
imgcopy=$('<img src="'+ $(this, 'img').attr('src') +'" />');//new object
imgcopy.attr( "id","mnbv1lk87jhy0aaa" );//Markup for a final removing
imgcopy.css({"visibility" : "hidden",'position':'absolute','left':'-9999px'});//hide copy
$(document.body).append (imgcopy);//append to document
alert("We get right dimensions: "+ imgcopy.width()+"/"+imgcopy.height());
$("#mnbv1lk87jhy0aaa").remove();
}
})( jQuery );
$(document).ready(function(){
$("img.toreaddimensions").click(function(){$(this).getDimensions();});
});
<img class="toreaddimensions"…
对于不希望更改原始位置或图像的函数。
$(this).clone().removeAttr("width").attr("width");
$(this).clone().removeAttr("height").attr("height);
这适用于我(safari 3.2)，从窗口内发射。onload事件:
$(window).load(function() {
var pic = $('img');
pic.removeAttr("width");
pic.removeAttr("height");
alert( pic.width() );
alert( pic.height() );
});
另一个建议是使用imagesLoaded插件。
$("img").imagesLoaded(function(){
alert( $(this).width() );
alert( $(this).height() );
});
在github检查这个存储库!
使用Javascript检查宽度和高度的好例子
https://github.com/AzizAK/ImageRealSize
-编辑的要求从一些评论。
Javascript代码:
function CheckImageSize(){
var image = document.getElementById("Image").files[0];
createReader(image, function (w, h) {
alert("Width is: " + w + " And Height is: "+h);
});
}
function createReader(file, whenReady) {
var reader = new FileReader;
reader.onload = function (evt) {
var image = new Image();
image.onload = function (evt) {
var width = this.width;
var height = this.height;
if (whenReady) whenReady(width, height);
};
image.src = evt.target.result;
};
reader.readAsDataURL(file);
}
和HTML代码:
<html>
<head>
<title>Image Real Size</title>
<script src="ImageSize.js"></script>
</head>
<body>
<input type="file" id="Image"/>
<input type="button" value="Find the dimensions" onclick="CheckImageSize()"/>
</body>
<html>
