javascript 如何找到base64图像的宽度和高度
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How to find the base64 image width and height
提问by vvr02
How to find the base64 image width and height
如何找到base64图像的宽度和高度
<img id="thumb0" width="200" height="200"
src="data:image/png;base64, ................">
Image property width and height are constant as i need to show them as thumb nail, but where as the original image properties are different.
图像属性宽度和高度是恒定的，因为我需要将它们显示为缩略图，但原始图像属性不同。
I need to get the original image height and width.
我需要获取原始图像的高度和宽度。
Suppose my original image height and width are 750 X 500
假设我的原始图像高度和宽度是750 X 500
I tried like this but getting the property width and height
我试过这样但得到属性宽度和高度
$("#thumb0").width();
value is 200.
值为200。
Please help how to get orginal width and height of the image.
请帮助如何获取图像的原始宽度和高度。
回答by Denys Séguret
You can build another image element and get its size :
您可以构建另一个图像元素并获取其大小：
var img = new Image();
img.src = $('#thumb0').attr('src');
var originalWidth = img.width;
回答by ycz6
The Image() constructor for HTMLImageElementsmentioned in dystroy's answer is the right way to go, but there's a caveat: The constructor is actually asynchronous! As a result, you may experience unexpected behavior in certain browsers; from my limited experiments, dystroy's code will work 100% of the time in Chrome, but only sometimes in Firefox and Safari. Don't know about others.
该图片（）构造函数HTMLImageElements在dystroy的答复中提到是正确的道路要走，但有一点需要注意：构造函数实际上是异步的！因此，您可能会在某些浏览器中遇到意外行为；从我有限的实验来看，dystroy 的代码在 Chrome 中可以 100% 运行，但有时在 Firefox 和 Safari 中可以运行。不知道别人怎么样。
The right way to do it seems to be with an onload handler, as in:
正确的做法似乎是使用 onload handler，如下所示：
var img = new Image();
img.src = some_base64_image_source;
console.log(img.width); // This might print out 0!
img.onload = function() {
console.log(img.width); // This will print out the width.
}
