上传前检查图像大小 [英] checking image size before upload

问题描述

我注意到在将个人资料图片上传到Twitter时，会在上传之前检查其大小。谁能指点我这样的解决方案？

I noticed when uploading a profile pic to Twitter that its size is checked before upload. Can anyone point me to a solution like this?

谢谢

推荐答案

我已经在chrome中测试了这个代码并且工作正常。

I have tested this code in chrome and it works fine.

var x = document.getElementById('APP_LOGO'); // get the file input element in your form
var f = x.files.item(0); // get only the first file from the list of files
var filesize = f.size;
alert("the size of the image is : "+filesize+" bytes");

var i = new Image();
var reader = new FileReader();
reader.readAsDataURL(f);
i.src=reader.result;
var imageWidth = i.width;
var imageHeight = i.height;
alert("the width of the image is : "+imageWidth);
alert("the height of the image is : "+imageHeight);

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