title: Ionic2 navController pop with params (CallBack)
body: <p>I want to make a callback between two page.
  In the page 1, i have this code:</p>
  
  <pre><code>  DataInfo= [
      {
         Price: 0,
         ClosePrice: 0,
         UpdateTime:"",
         DefaultPrice:0
      }
  
    ] 
  
  GetClosePrice(i):number{
  return DataInfo[i].ClosePrice;
  }
  </code></pre>
  
  <p>i want to get the value of 'i' from the page 2, How can i load the function GetClosePrice() when the navcontroller return to the page 1 (this.navCtrl.pop())</p>