js 判断上传文件大小及格式代码_javascript技巧

var url = window.location.href, type = url.substr(url.lastIndexOf('/')+1);
// console.log(type);
var allowType = {
".bmp":1, ".png":1, ".jpeg":1, ".jpg":1, ".gif":1,
".mp3":2, ".wma":2, ".wav":2, ".amr":2,
".rm":3, ".rmvb":3, ".wmv":3, ".avi":3, ".mpg":3, ".mpeg":3, ".mp4":3
};
var allowSize = {1:2097152, 2:5242880, 3:20971520};
var errMsg = {
"0" : '图片格式不正确
'
+ '音频格式不正确
'
+ '视频格式不正确
',
"1" : ‘图片格式不正确',
"2" : '音频格式不正确',
"3" : '视频格式不正确'
};
var errSizeMsg = {
'1':'图片文件小于2M',
'2':'音频文件小于5M',
'3':'视频文件小于20M',
}
function checkFileType(filename, type){
var ext = filename.substr(filename.lastIndexOf(".")).toLowerCase(),
res = allowType[ext];
if (type == 0) {
return !!res;
} else {
return type == res;
}
}
function checkFileSize(target, size){
var isIE = /msie/i.test(navigator.userAgent) && !window.opera;
var fileSize = 0;
if (isIE && !target.files)
{
var filePath = target.value;
var fileSystem = new ActiveXObject("Scripting.FileSystemObject");
var file = fileSystem.GetFile (filePath);
fileSize = file.Size;
} else {
fileSize = target.files[0].size;
}
// var fsize = fileSize / 1024*1024;
if(parseInt(fsize) >= parseInt(size)){
return false;
}else{
return true;
}
}
function upload(obj){
var filename = jQuery.trim(jQuery('#uploadFile').val());
if (!filename || filename == ""){ // 提交前的再次检测
alert('选择需要上传的文件');
return false;
}
if (!checkFileType(filename, type)){
alert('文件格式不正确');
return false;
}
var ext = filename.substr(filename.lastIndexOf(".")).toLowerCase();
var res = allowType[ext];
if(!checkFileSize(obj,allowSize[res])){
alert(errSizeMsg[res]);
return false;
}
//其他处理
}
//uploadFile为上传控件的id，obj为上传控件的本身（this）