如何使用简单的Javascript获取文件的上传大小? [英] How can I get a file's upload size using simple Javascript?

问题描述

我在页面之一上具有上传文件功能.我使用JavaScript检查文件的扩展名.现在，我想限制用户上传大于1 MB的文件.有什么方法可以使用JavaScript检查文件上传大小.

I have upload file functionality on one of the page. I check for the extension of the file using JavaScript. Now i want to restrict the user from uploading file greater than 1 MB. Is there any way i can check the file upload size using JavaScript.

我的代码当前如下所示:

My code currently look like this:

<script language="JavaScript">
function validate() {
   var filename = document.getElementById("txtChooseFile").value;
   var ext = getExt(filename);
   if(ext == "txt" || ext == "csv")
      return true;
   alert("Please upload Text files only.");
   return false;
}

function getExt(filename) {
   var dot_pos = filename.lastIndexOf(".");
   if(dot_pos == -1)
      return "";
   return filename.substr(dot_pos+1).toLowerCase();
}
</script>

推荐答案

除了获取文件名外，您无法通过javascript找出有关文件的任何其他详细信息，包括文件大小.

Other that aquiring the filename there is no way for you to find out any other details about the file in javascript including its size.

相反，您应该配置服务器端脚本以阻止过大的上传.

Instead you should configure server-side script to block an oversized upload.

这篇关于如何使用简单的Javascript获取文件的上传大小?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！