jQuery JS - 从 base64 代码中获取图像宽度和高度
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/17774928/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
JS - get image width and height from the base64 code
提问by bombastic
回答by gp.
var i = new Image();
i.onload = function(){
alert( i.width+", "+i.height );
};
i.src = imageData;
回答by EscapeNetscape
For synchronous use just wrap it into a promise like this:
对于同步使用，只需将其包装成这样的承诺：
function getImageDimensions(file) {
return new Promise (function (resolved, rejected) {
var i = new Image()
i.onload = function(){
resolved({w: i.width, h: i.height})
};
i.src = file
})
}
then you can use await to get the data in synchronous coding style:
那么您可以使用 await 以同步编码样式获取数据：
var dimensions = await getImageDimensions(file)
回答by Bill Keller
I found that using .naturalWidthand .naturalHeighthad the best results.
我发现使用.naturalWidth并.naturalHeight获得了最好的结果。
const img = new Image();
img.src = 'https://via.placeholder.com/350x150';
img.onload = function() {
const imgWidth = img.naturalWidth;
const imgHeight = img.naturalHeight;
console.log('imgWidth: ', imgWidth);
console.log('imgHeight: ', imgHeight);
};
This is only supported in modern browsers. http://www.Hymanlmoore.com/notes/naturalwidth-and-naturalheight-in-ie/
这仅在现代浏览器中受支持。http://www.Hymanlmoore.com/notes/naturalwidth-and-naturalheight-in-ie/
回答by Desu
Create a hidden <img>with that image and then use jquery .width() and . height()
创建一个隐藏的<img>图像，然后使用 jquery .width() 和 . 高度（）
$("body").append("<img id='hiddenImage' src='"+imageData+"' />");
var width = $('#hiddenImage').width();
var height = $('#hiddenImage').height();
$('#hiddenImage').remove();
alert("width:"+width+" height:"+height);
Test here: FIDDLE
在这里测试： FIDDLE
Image is not initially created hidden. it gets created, then you get width and height and then remove it. This may cause a very short visibility in large images in this case you have to wrap the image in another container and make that container hidden not the image itself.
图像最初不是创建隐藏的。它被创建，然后你得到宽度和高度，然后将其删除。这可能会导致大图像的可见性非常短，在这种情况下，您必须将图像包装在另一个容器中，并使该容器隐藏而不是图像本身。
Another Fiddle that does not add to dom as per gp.'s anser : HERE
另一个没有按照 gp. 的 anser 添加到 dom 的小提琴： 这里
