js method to implement preview of uploaded images

<tr>
<td>缩略图</td>
<td>
　　<a href="javascript::void(0)" class="fileBtn">
　　选择文件
　　<input type="file" id="file_pic">
　　</a>
</td>
</tr>
<tr>
<td></td>
<td><img  id="file_view"   style="max-width:90%" alt="js method to implement preview of uploaded images" ></td>
</tr>

// 下面用于图片上传预览功能 objc : { file, pic, width }
  
yqUI.setImagePreview = function(objc) {
  
 var docObj=document.getElementById(objc.file);
  
 var imgObjPreview=document.getElementById(objc.pic);
 if(docObj.files &&docObj.files[0]){
  
  imgObjPreview.style.display = 'block';
  imgObjPreview.style.width = objc.width;
  imgObjPreview.src = window.URL.createObjectURL(docObj.files[0]);
    
  return true;
 } else {
  return false;
 };
  
};
  
// 使用该控件, opts 配置对象
  
var opts = {
　　file : 'file_pic',
　　pic : 'file_view',
　　width : '180px'
}
  
yqUI.setImagePreview(opts);