title: Convert list to ObservableCollection
body: <p>i need to convert my list which i get from an api call, to a ObservableCollection to put into my graph.</p>
  
  <p>i tried these 2 methods:</p>
  
  <p>method1:</p>
  
  <pre><code>ObservableCollection&lt;ChartDataModel&gt; test = new ObservableCollection&lt;ChartDataModel&gt;(_CoinHistoryGraph as List&lt;CoinHistoryModel&gt;);
  </code></pre>
  
  <p>error on method 1:</p>
  
  <pre><code>cannot convert from 'System.Collections.Generic.List&lt;CoinMarketCap.SHARED.Models.CoinHistoryModel&gt;' to 'System.Collections.Generic.List&lt;CoinMarketCap.SHARED.ViewModels.ChartDataModel&gt;'    CoinMarketCap.SHARED    
  </code></pre>
  
  <p>Method2: </p>
  
  <pre><code>CoinHistory = _CoinHistoryGraph.Select(x =&gt; new ChartDataModel(float.Parse(x.price_btc), double.Parse(x.timestamp)));
  </code></pre>
  
  <p>error on method2:</p>
  
  <pre><code>'System.Collections.Generic.IEnumerable&lt;CoinMarketCap.SHARED.ViewModels.ChartDataModel&gt;' to 'System.Collections.ObjectModel.ObservableCollection&lt;CoinMarketCap.SHARED.ViewModels.ChartDataModel&gt;'.
  </code></pre>
  
  <p>Models:</p>
  
  <pre><code> public class GraphModel
  {
      public GraphModel(float pricebtc, double time_stamp)
      {
          price_btc = pricebtc;
          timestamp = time_stamp;
      }
  
      public float price_btc { get; set; }
      public double timestamp { get; set; }
  }
  
    public class CoinHistoryModel
  {
      public string name { get; set; }
      public string price_btc { get; set; }
      public string timestamp { get; set; }
  
  }
  </code></pre>