jQuery插件imgPreviewQs实现上传图片预览

/*!
  依赖 jQuery 1.5.2 
  (c) 2016 
  license: http://www.opensource.org/licenses/mit-license.php
*/
(function($){
$.fn.imgPreviewQs = function(options){
  function isIE(ver){
    var b = document.createElement('b')
    b.innerHTML = '<!--[if IE ' + ver + ']><i></i><![endif]-->'
    return b.getElementsByTagName('i').length === 1;
  }
   
  options = $.extend( {}, $.fn.imgPreviewQs.defaults,options);
  var $this =$(this);
  $this.change(function(){
    var regex=/(.*)\.(jpg|jpeg|gif|bmp|png)$/;
    var val = $this.val();
    if(!regex.test(val)){
      alert("请选择图片");
      return false;
    }
    if(browserQs.isIE(8)){
      HanderIE789($this);
    }
    else if(window.FileReader){
      HanderFileReader($this);
    }
    else if(browserQs.isIE(9)){
      HanderIE789($this);
    }
    else if(browserQs.isIE(6)){
      HanderOther($this);
    }
    else if(browserQs.isIE(7)){
      HanderIE789($this);
    }
    else{
      $("#"+options.destID).html("浏览器不支持预览图片");
    }
  });
   
  function HanderFileReader($this){
    var oPreviewImg = null, oFReader = new window.FileReader(),
    rFilter = /^(?:image\/bmp|image\/cis\-cod|image\/gif|image\/ief|image\/jpeg|image\/jpeg|image\/jpeg|image\/pipeg|image\/png|image\/svg\+xml|image\/tiff|image\/x\-cmu\-raster|image\/x\-cmx|image\/x\-icon|image\/x\-portable\-anymap|image\/x\-portable\-bitmap|image\/x\-portable\-graymap|image\/x\-portable\-pixmap|image\/x\-rgb|image\/x\-xbitmap|image\/x\-xpixmap|image\/x\-xwindowdump)$/i;
    oFReader.onload = function (oFREvent) 
    {
      $("#"+options.destID).html("<img src='"+oFREvent.target.result+"' style='width:100%;height:100%;'/>");
    };
     
    var aFiles = $this.get(0).files;
    if (aFiles.length === 0) { return; }
    if (!rFilter.test(aFiles[0].type)) { alert("请选择图片"); return; }
    oFReader.readAsDataURL(aFiles[0]);
  }
   
  function HanderIE789($this){
    $("#"+options.destID).css("filter","progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src='"+getUrl($this)+"')");
  }
   
  function HanderOther($this){
    $("#"+options.destID).html("<img src='"+$this.val()+"' style='width:100%;height:100%;'/>");
  }
   
  function getUrl($this){
    $this.select();
    $this.blur();
    var imgSrc =document.selection.createRange().text;
    document.selection.empty();
    return imgSrc;
  }
}; 
$.fn.imgPreviewQs.defaults = {
    destID:""
};
})(jQuery);