js判斷上傳文件的寬高,類型,filesize

<script type="text/javascript">

        UpLoadFileCheck = function () {
            this.AllowExt = ".jpg,.gif,.png,.jpeg"; //允許上傳的文件類型 0為無限制 每個擴展名后邊要加一個"," 小寫字母表示
            this.AllowImgFileSize = 1; //允許上傳文件的大小 0為無限制 單位：KB
            this.AllowImgWidth = 10; //允許上傳的圖片的寬度 0為無限制　單位：px(像素)
            this.AllowImgHeight = 10; //允許上傳的圖片的高度 0為無限制　單位：px(像素)
            this.ImgObj = new Image();
            this.ImgFileSize = 0;
            this.ImgWidth = 0;
            this.ImgHeight = 0;
            this.FileExt = "";
            this.ErrMsg = "";
            this.IsImg = false; //全局變量

        }

        UpLoadFileCheck.prototype.CheckExt = function (obj) {
            this.ErrMsg = "";
            this.ImgObj.src = obj.value;
            //this.HasChecked=false;  
            if (obj.value == "") {
                this.ErrMsg = "\n請選擇一個文件";
            }
            else {
                this.FileExt = obj.value.substr(obj.value.lastIndexOf(".")).toLowerCase();
                if (this.AllowExt != 0 && this.AllowExt.indexOf(this.FileExt) == -1)//判斷文件類型是否允許上傳
                {
                    this.ErrMsg = "\n該文件類型不允許上傳。請上傳 " + this.AllowExt + " 類型的文件，當前文件類型為" + this.FileExt;
                }
            }
            if (this.ErrMsg != "") {
                this.ShowMsg(this.ErrMsg, false);
                return false;
            }
            else
                return this.CheckProperty(obj);
        }

        UpLoadFileCheck.prototype.CheckProperty = function (obj) {
            if (this.ImgObj.readyState != "complete")//
            {
                sleep(1000); //一秒使用圖能完全加載    
            }

            if (this.IsImg == true) {
                this.ImgWidth = this.ImgObj.width; //取得圖片的寬度
                this.ImgHeight = this.ImgObj.height; //取得圖片的高度
                if (this.AllowImgWidth != 0 && this.AllowImgWidth < this.ImgWidth)
                    this.ErrMsg = this.ErrMsg + "\n圖片寬度超過限制。請上傳寬度小於" + this.AllowImgWidth + "px的文件，當前圖片寬度為" + this.ImgWidth + "px";

                if (this.AllowImgHeight != 0 && this.AllowImgHeight < this.ImgHeight)
                    this.ErrMsg = this.ErrMsg + "\n圖片高度超過限制。請上傳高度小於" + this.AllowImgHeight + "px的文件，當前圖片高度為" + this.ImgHeight + "px";
            }

            this.ImgFileSize = Math.round(this.ImgObj.fileSize / 1024 * 100) / 100; //取得圖片文件的大小  
            if (this.AllowImgFileSize != 0 && this.AllowImgFileSize < this.ImgFileSize)
                this.ErrMsg = this.ErrMsg + "\n文件大小超過限制。請上傳小於" + this.AllowImgFileSize + "KB的文件，當前文件大小為" + this.ImgFileSize + "KB";

            if (this.ErrMsg != "") {
                this.ShowMsg(this.ErrMsg, false);
                return false;
            }
            else
                return true;
        }

        UpLoadFileCheck.prototype.ShowMsg = function (msg, tf)//顯示提示信息 tf=false 顯示錯誤信息 msg-信息內容
        {
            /*msg=msg.replace("\n","<li>");
            msg=msg.replace(/\n/gi,"<li>");
            */
            alert(msg);
        }
        function sleep(num) {
            var tempDate = new Date();
            var tempStr = "";
            var theXmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
            while ((new Date() - tempDate) < num) {
                tempStr += "\n" + (new Date() - tempDate);
                try {
                    theXmlHttp.open("get", "about:blank?JK=" + Math.random(), false);
                    theXmlHttp.send();
                }
                catch (e) { ; }
            }
            //containerDiv.innerText=tempStr;  
            return;
        }

        function c(obj) {
            var d = new UpLoadFileCheck();
            d.IsImg = true;
            d.AllowImgFileSize = 100;
            d.CheckExt(obj)
        }
        //調用 <input name="" type="file" onchange="c(this)" />
    </script>

 

<script type="text/javascript">
function ajaxFunction()
{
  var xmlHttp;
  try
{
    // Firefox, Opera 8.0+, Safari
    xmlHttp=new XMLHttpRequest();
}
  catch (e)
{
    // Internet Explorer
    try
    {
      xmlHttp=new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (e)
    {
      try
      {
        xmlHttp=new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch (e)
      {
        alert("您的瀏覽器不支持AJAX!");
        return false;
      }
    }
}
}
</script>