JS判断上传文件是否符合格式和大小要求

<input id="File1" type="file" onchange="checkFile(this)" />

 

JS:

function checkFile(fileObj)

{

        var max = 4;

        var fso = new ActiveXObject("Scripting.FileSystemObject");

        if(fso.GetFile(fileObj.value).size> max*1024*1024)

        {

            alert("附件不能超过" + max + "MB，请重新上传");

            fileObj.outerHTML = fileObj.outerHTML;

            fileObj.value = "";

        }

        var type = ".doc.wps.pdf";

        if(type.indexOf(fileObj.value.substr(fileObj.value.lastIndexOf(".")).toLowerCase())==-1)

        {

            alert("文件格式必须为：" + type);

            fileObj.outerHTML = fileObj.outerHTML;

            fileObj.value = "";

        }

}