Question

可能重复：
  Determining image file size + dimensions via Javascript?
  How to upload preview image before upload through JavaScript
  get image height and width in file tag using javascript

如何在文件标签中没有页面刷新的情况下获得图像的高度和宽度？

<HTML>

<HEAD>

<TITLE></TITLE>

<script language="javascript">

function getW()

{

var theImg = document.getElementById('testimg');

alert(theImg.width);

}

function getH()

{

var theImg = document.getElementById('testimg');

alert(theImg.height);

}

</script>

</HEAD>



<BODY>


<input type="file" id="testimg"/>

<input type="button" value="get Width" onclick="getW()"/>

<input type="button" value="get Height" onclick="getH()"/>

</BODY>

</HTML>

我使用php代码获取图像的图像高度和宽度，但该时间页面将刷新，没有页面刷新我得到图像大小但不是高度和宽度....

Answer 1

JavaScript无法访问浏览器计算机的文件系统。它无法读取该文件的宽度和高度。

Answer 2

请阅读本文

Should setting an image src to data URL be available immediately?

How to upload preview image before upload through JavaScript

在文件标签javascript中获取图像高度和宽度

2 个答案: