title: Xamarin forms xaml button click handler not fired c#
body: <p>I has rey use VS 2015 with xamarin forms to create a cross platform project. I add the xaml page which contain a text box and button. In the code behind, I has code as below</p>
  
  <pre><code>public Inno()
  {
     InitializeComponent();
     btntest.Clicked += Btntest_Clicked;
   }
  
  Private void Btntest_Clicked(object sender, EventArgs e)
  {
      if(string.IsNullOrEmpty(Name.Text))
      {                
          return;
      }
  }
  </code></pre>
  
  <p>When I run the android simulator to test the page, it fire the constructor. But when I clicke the button, it not fire the click event. Anything goes wrong? Please help. Thanks</p>