js实现图片上传并正常显示

<label for="thumbnail" class="col-md-3 control-label">缩略图</label>
<div class="col-md-6">
 <input type="file" class="form-control" id="thumbnail" name="thumbnail">
</div>

function getObjectURL(file) {
 var url = null ;
 if (window.createObjectURL!=undefined) { // basic
 url = window.createObjectURL(file) ;
 } else if (window.URL!=undefined) { // mozilla(firefox)
 url = window.URL.createObjectURL(file) ;
 } else if (window.webkitURL!=undefined) { // webkit or chrome
 url = window.webkitURL.createObjectURL(file) ;
 }
 return url ;
}

$('#thumbnail').change(function() {
 var eImg = $('<img />');
 eImg.attr('src', getObjectURL($(this)[0].files[0])); // 或 this.files[0] this->input
 $(this).after(eImg);});

<form action='' method='post' name='myform'>
 <input type='file' id='iptfileupload' onchange='show()' value='' />
 <img src='1.jpg' alt='' id='img' />
</form>

<script type="text/javascript">
 function getPath(obj,fileQuery,transImg) {

 var imgSrc = '', imgArr = [], strSrc = '' ;

 if(window.navigator.userAgent.indexOf("MSIE")>=1){ // IE浏览器判断
 if(obj.select){
  obj.select();
  var path=document.selection.createRange().text;
  alert(path) ;
  obj.removeAttribute("src");
  imgSrc = fileQuery.value ;
  imgArr = imgSrc.split('.') ;
  strSrc = imgArr[imgArr.length - 1].toLowerCase() ;
  if(strSrc.localeCompare('jpg') === 0 || strSrc.localeCompare('jpeg') === 0 || strSrc.localeCompare('gif') === 0 || strSrc.localeCompare('png') === 0){
  obj.setAttribute("src",transImg);
  obj.style.filter=
  "progid:DXImageTransform.Microsoft.AlphaImageLoader(src='"+path+"', sizingMethod='scale');"; // IE通过滤镜的方式实现图片显示
  }else{
  //try{
  throw new Error('File type Error! please image file upload..'); 
  //}catch(e){
  // alert('name: ' + e.name + 'message: ' + e.message) ;
  //}
  }
 }else{
  // alert(fileQuery.value) ;
  imgSrc = fileQuery.value ;
  imgArr = imgSrc.split('.') ;
  strSrc = imgArr[imgArr.length - 1].toLowerCase() ;
  if(strSrc.localeCompare('jpg') === 0 || strSrc.localeCompare('jpeg') === 0 || strSrc.localeCompare('gif') === 0 || strSrc.localeCompare('png') === 0){
  obj.src = fileQuery.value ;
  }else{
  //try{
  throw new Error('File type Error! please image file upload..') ;
  //}catch(e){
  // alert('name: ' + e.name + 'message: ' + e.message) ;
  //}
  }

 }

 } else{
 var file =fileQuery.files[0];
 var reader = new FileReader();
 reader.onload = function(e){

  imgSrc = fileQuery.value ;
  imgArr = imgSrc.split('.') ;
  strSrc = imgArr[imgArr.length - 1].toLowerCase() ;
  if(strSrc.localeCompare('jpg') === 0 || strSrc.localeCompare('jpeg') === 0 || strSrc.localeCompare('gif') === 0 || strSrc.localeCompare('png') === 0){
  obj.setAttribute("src", e.target.result) ;
  }else{
  //try{
  throw new Error('File type Error! please image file upload..') ;
  //}catch(e){
  // alert('name: ' + e.name + 'message: ' + e.message) ;
  //}
  }

  // alert(e.target.result); 
 }
 reader.readAsDataURL(file);
 }
 }

 function show(){
 //以下即为完整客户端路径
 var file_img=document.getElementById("img"),
 iptfileupload = document.getElementById('iptfileupload') ;
 getPath(file_img,iptfileupload,file_img) ;
 }
 </script>