我试图显示从本地机器选择的图像，我需要该图像的位置用于JavaScript函数。但我查不到地址。
为了获得图像位置，我尝试使用console.log，但没有返回任何结果。
console.log(document.getElementById("uploadPreview"));
下面是HTML代码:
<!DOCTYPE html>
<html>
<head>
<title></title>
</head>
<body>
<div align="center" style="padding-top: 50px">
<img align="center" id="uploadPreview" style="width: 100px; height: 100px;" />
</div>
<div align="center" style="padding-left: 30px">
<input id="uploadImage" type="file" name="myPhoto" onchange="PreviewImage();" />
</div>
<script type="text/javascript">
function PreviewImage() {
var oFReader = new FileReader();
oFReader.readAsDataURL(document.getElementById("uploadImage").files[0]);
oFReader.onload = function (oFREvent) {
document.getElementById("uploadPreview").src = oFREvent.target.result;
console.log(document.getElementById("uploadPreview").src);
};
}
</script>
</body>
</html>
控制台输出:
以下是警告:
DevTools无法加载SourceMap:无法加载内容
chrome扩展:/ / alplpnakfeabeiebipdmaenpmbgknjce / include.preload.js.map:
HTTP错误:状态代码404,net::ERR_UNKNOWN_URL_SCHEME
对我来说，这些警告是由Selenium IDE Chrome扩展引起的。这些警告出现在控制台中每次页面加载:
DevTools failed to load source map: Could not load content for chrome-extension://mooikfkahbdckldjjndioackbalphokd/assets/atoms.js.map: HTTP error: status code 404, net::ERR_UNKNOWN_URL_SCHEME
DevTools failed to load source map: Could not load content for chrome-extension://mooikfkahbdckldjjndioackbalphokd/assets/polyfills.js.map: HTTP error: status code 404, net::ERR_UNKNOWN_URL_SCHEME
DevTools failed to load source map: Could not load content for chrome-extension://mooikfkahbdckldjjndioackbalphokd/assets/escape.js.map: HTTP error: status code 404, net::ERR_UNKNOWN_URL_SCHEME
DevTools failed to load source map: Could not load content for chrome-extension://mooikfkahbdckldjjndioackbalphokd/assets/playback.js.map: HTTP error: status code 404, net::ERR_UNKNOWN_URL_SCHEME
DevTools failed to load source map: Could not load content for chrome-extension://mooikfkahbdckldjjndioackbalphokd/assets/record.js.map: HTTP error: status code 404, net::ERR_UNKNOWN_URL_SCHEME
由于Selenium IDE已经设置为能够读取所有站点上的站点数据，所以我卸载了它。(我在这里读到另一个评论，你可以尝试为一个扩展启用更多权限，而不是删除它。)在我的情况下，删除硒IDE (Chrome扩展)摆脱了警告。
正确:这与你的代码无关。对于这个警告，我找到了两个有效的解决方案(不仅仅是禁用它)。为了更好地理解源映射是什么，我建议你看看这个答案，它解释了它是如何帮助你调试的:
The .map files are for JavaScript and CSS (and now TypeScript too) files that have been minified. They are called SourceMaps. When you minify a file, like the angular.js file, it takes thousands of lines of pretty code and turns it into only a few lines of ugly code. Hopefully, when you are shipping your code to production, you are using the minified code instead of the full, unminified version. When your app is in production, and has an error, the sourcemap will help take your ugly file, and will allow you to see the original version of the code. If you didn't have the sourcemap, then any error would seem cryptic at best.
First solution: apparently, Mr Heelis was the closest one: you should add the .map file and there are some tools that help you with this problem (Grunt, Gulp and Google closure for example, quoting the answer). Otherwise you can download the .map file from official sites like Bootstrap, jQuery, font-awesome, preload and so on... (maybe installing things like popper or swiper by the npm command in a random folder and copying just the .map file in your JavaScript/CSS destination folder)
Second solution (the one I used): add the source files using a CDN (content delivery network). (Here are all the advantages of using a CDN). Using content delivery network (CDN) you can simply add the CDN link, instead of the path to your folder. You can find CNDs on official websites (Bootstrap, jquery, popper, etc.) or you can easily search on some websites like Cloudflare, cdnjs, etc.
