本文转自:http://www.micmiu.com/lang/javascript/js-check-filesize/
目录
- 基本思路
- 示例
[一]、基本思路
在FireFox、Chrome浏览器中可以根据document.getElementById(“id_file”) .files[0].size获取上传文件的大小（字节数），而IE浏览器中不支持该属性，只能借助<img >标签的dynsrc属性，来间接实现获取文件的大小（但需要同意ActiveX控件的运行）。
[二]、示例
测试代码：filesize-check.html
1 |
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd "> |
2 |
< html xmlns = " http://www.w3.org/1999/xhtml " >
|
3 |
< head >
|
4 |
< meta name = "DEscription" contect = "my code demo" />
|
5 |
< meta name = "Author" contect = "Michael@www.micmiu.com" />
|
6 |
< meta http-equiv = "Content-Type" content = "text/html; charset=utf-8" />
|
7 |
< title >js check file size @ www.micmiu.com</ title >
|
8 |
</ head >
|
9 |
< body >
|
10 |
< img id = "tempimg" dynsrc = "" src = "" style = "display:none" />
|
11 |
< input type = "file" name = "file" id = "fileuploade" size = "40" />
|
12 |
< input type = "button" name = "check" value = "checkfilesize" onclick ="checkfile()" />
|
13 |
14 |
</ body >
|
15 |
< script type = "text/javascript" >
|
16 |
var maxsize = 2*1024*1024;//2M
|
17 |
var errMsg = "上传的附件文件不能超过2M！！！";
|
18 |
var tipMsg = "您的浏览器暂不支持计算上传文件的大小，确保上传文件不要超过2M，建议使用IE、FireFox、Chrome浏览器。";
|
19 |
var browserCfg = {};
|
20 |
var ua = window.navigator.userAgent;
|
21 |
if (ua.indexOf("MSIE")>=1){
|
22 |
browserCfg.ie = true;
|
23 |
}else if(ua.indexOf("Firefox")>=1){
|
24 |
browserCfg.firefox = true;
|
25 |
}else if(ua.indexOf("Chrome")>=1){
|
26 |
browserCfg.chrome = true;
|
27 |
}
|
28 |
function checkfile(){
|
29 |
try{
|
30 |
var obj_file = document.getElementById("fileuploade");
|
31 |
if(obj_file.value==""){
|
32 |
alert("请先选择上传文件");
|
33 |
return;
|
34 |
}
|
35 |
var filesize = 0;
|
36 |
if(browserCfg.firefox || browserCfg.chrome ){
|
37 |
filesize = obj_file.files[0].size;
|
38 |
}else if(browserCfg.ie){
|
39 |
var obj_img = document.getElementById('tempimg');
|
40 |
obj_img.dynsrc=obj_file.value;
|
41 |
filesize = obj_img.fileSize;
|
42 |
}else{
|
43 |
alert(tipMsg);
|
44 |
return;
|
45 |
}
|
46 |
if(filesize==-1){
|
47 |
alert(tipMsg);
|
48 |
return;
|
49 |
}else if(filesize>maxsize){
|
50 |
alert(errMsg);
|
51 |
return;
|
52 |
}else{
|
53 |
alert("文件大小符合要求");
|
54 |
return;
|
55 |
}
|
56 |
}catch(e){
|
57 |
alert(e);
|
58 |
}
|
59 |
}
|
60 |
</ script >
|
61 |
</ html >
|
测试上传的文件大小：
各浏览器中的效果如下：
IE8：
FF(11.0)：
Chrome(19.0.1084.56 m)：
—————–
原创文章，转载请注明：转载自micmiu –软件开发+生活点滴 [ http://www.micmiu.com/ ]
本文链接地址: http://www.micmiu.com/lang/javascript/js-check-filesize/