js判断图片大小方法

//判断照片大小

function getPhotoSize(obj){

    var fileSize = 0;

    var isIE = /msie/i.test(navigator.userAgent) && !window.opera;           

    if (isIE && !obj.files) {         

         var filePath = obj.value;           

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

         var file = fileSystem.GetFile (filePath);              

         fileSize = file.Size;        

    }else { 

         fileSize = obj.files[0].size;    

    }

    fileSize=Math.ceil(fileSize/1024); //单位为KB

     

    return fileSize;

}

<input name="file" size="30" type="file" onchange="getFileSize(this.value)" />