c# - Xamarin.Forms: ListView are not being Displayed on Xamarin.Droid -

i'm creating xamarin.forms portable application. have database in visual studio , want display data inside xamarin listview. whenever that, data not being displayed on xamarin.droid leaving blank space. tried in uwp , worked. how in xamarin.droid?

(screenshot of xamarin.droid)

notice listview still occupy space if records not being displayed. think reason behind this? check in web api if data being retrieved , does.

meaning, real problem occurs in displaying records on listview. hope can me.

here codes i've tried.

clientlist.xaml

<?xml version="1.0" encoding="utf-8" ?> <contentpage xmlns="http://xamarin.com/schemas/2014/forms"          xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"          x:class="xamarinformsdemo.views.clientlistpage"          xmlns:viewmodels="clr-namespace:xamarinformsdemo.viewmodels;assembly=xamarinformsdemo"          xmlns:controls="clr-namespace:imagecircle.forms.plugin.abstractions;assembly=imagecircle.forms.plugin.abstractions"          backgroundimage="bg3.jpg"          title="client list">     <contentpage.bindingcontext>     <viewmodels:customervm/>   </contentpage.bindingcontext>   <stacklayout orientation="vertical">      <searchbar placeholder="search" text="{binding keyword}" searchcommand="{binding searchcommand}" x:name="txtsearch" />      <listview itemssource="{binding customerlist}"           hasunevenrows="true">       <listview.itemtemplate>     <datatemplate>       <viewcell>         <grid padding="10" rowspacing="10" columnspacing="5">           <grid.rowdefinitions>             <rowdefinition height="auto"/>             <rowdefinition height="*"/>           </grid.rowdefinitions>           <grid.columndefinitions>             <columndefinition width="auto"/>             <columndefinition width="*"/>           </grid.columndefinitions>            <controls:circleimage source="icon.png"                  heightrequest="66"                  horizontaloptions="centerandexpand"                  aspect="aspectfill"                  widthrequest="66"                  grid.rowspan="2"                />             <label grid.column="1"                  text="{binding customer_name}"                  textcolor="#24e97d"                  fontsize="24"/>              <label grid.column="1"                   grid.row="1"                    text="{binding customer_code}"                    textcolor="white"                    fontsize="18"                    opacity="0.6"/>             <label grid.column="1"               grid.row="2"               text="{binding customer_contact}"                textcolor="white"                fontsize="18"                opacity="0.6"/>            </grid>       </viewcell>     </datatemplate>   </listview.itemtemplate>  </listview>       <stacklayout orientation="vertical"          padding="30,10,30,10"          heightrequest="20"          backgroundcolor="#24e97d"          verticaloptions="center"          opacity="0.5">   <label text="© copyright 2016   smesoft.com.ph   rights reserved "          horizontaltextalignment="center"          verticaloptions="center"          horizontaloptions="center" />     </stacklayout>   </stacklayout>  </contentpage> 

clientlistviewmodel.cs

using system; using system.collections.generic; using system.collections.objectmodel; using system.componentmodel; using system.diagnostics; using system.linq; using system.runtime.compilerservices; using system.text; using system.threading.tasks; using system.windows.input; using xamarin.forms; using xamarinformsdemo.models; using xamarinformsdemo.services;  namespace xamarinformsdemo.viewmodels {     public class customervm : inotifypropertychanged     {       private list<customer> _customerlist; // keep customers     private list<customer> _searchedcustomerlist; // keep copy searching     private customer _selectedcustomer = new customer();      private string _keyword = "";     public string keyword     {                 {             return _keyword;         }         set         {             this._keyword = value;              // while keyword changed filter employees             //filter();         }     }        private void filter()     {         if (string.isnullorwhitespace(_keyword))         {             customerlist = _searchedcustomerlist;          }         else         {             // var lowerkeyword = _keyword.tolower();             customerlist = _searchedcustomerlist.where(r => r.customer_name.tolower().contains(_keyword.tolower())).tolist();             //  employeeslist = _searchedemployeeslist.where(r => r.employee_name.contains(_keyword)).tolist();           }     }         public list<customer> customerlist     {                 {             return _customerlist;         }         set         {             _customerlist = value;             onpropertychanged();         }     }       public icommand searchcommand     {                 {             return new command((sender) =>             {                 //var searchbar = (searchbar)sender;                 //this.keyword = searchbar.text;                 filter();             });         }     }        public customervm()     {         initializedataasync();     }      private async task initializedataasync()     {         var customerservices = new customerservices();         _searchedcustomerlist = await customerservices.getcustomerasync();         customerlist = await customerservices.getcustomerasync();      }       public event propertychangedeventhandler propertychanged;      protected virtual void onpropertychanged([callermembername] string propertyname = null)     {         var handler = propertychanged;         if (handler != null) handler(this, new propertychangedeventargs(propertyname));     }       } } 

customerservice.cs

using plugin.restclient; using system; using system.collections.generic; using system.collections.objectmodel; using system.linq; using system.text; using system.threading.tasks; using xamarinformsdemo.models;  namespace xamarinformsdemo.services {     public class customerservices     {     public async task<list<customer>> getcustomerasync()     {         restclient_customer<customer> restclient = new restclient_customer<customer>();          var customerlist = await restclient.getcustomerasync();//yung getasync ay pantawag restclient          return customerlist;         }       } } 

restclient.cs

  public class restclient_customer <t> {       private const string webserviceurl = "http://localhost:50857/api/customer/";      public async task<list<t>> getcustomerasync()     {         var httpclient = new httpclient();          var json = await httpclient.getstringasync(webserviceurl);          var taskmodels = jsonconvert.deserializeobject<list<t>>(json);          return taskmodels;     }  } 

in viewmodel change

public list<customer> customerlist 

to

public observablecollection<customer> customerlist 

and in xaml, change

 <listview itemssource="{binding customerlist}" 

to

 <listview itemssource="{binding customerlist, mode=twoway}"