title: UWP Preventing MessageDialog from Closing Parent ContentDialog
body: <p>My app uses ContentDialog as a mean for data insertion. In other words; the data form is a ContentDialog. During validating the user input, the app shall prompt any error to the user by using MessageDialog. However, dismissing the MessageDialog will also dismissing the ContentDialog. </p>
  
  <p>Here is the chunk of the code when the alert is shown:</p>
  
  <pre><code>private void ContentDialog_PrimaryButtonClick(ContentDialog sender, ContentDialogButtonClickEventArgs args)
  {
      //save item
      ValidateForm();
  }
  
  private void ContentDialog_SecondaryButtonClick(ContentDialog sender, ContentDialogButtonClickEventArgs args)
  {
  }
  
  private async void ValidateForm()
  {
      //Ensure all fields are filled
      String barcode = BarcodeText.Text.Trim();
      String desc = DescText.Text.Trim();
      String cost = CostText.Text.Trim();
      String price = PriceText.Text.Trim();
      String stock = StockText.Text.Trim();
  
      if(barcode.Equals(String.Empty) || desc.Equals(String.Empty) ||
              desc.Equals(String.Empty) || cost.Equals(String.Empty) || 
              price.Equals(String.Empty) || stock.Equals(String.Empty))
      {
          var dialog = new MessageDialog("Please fill in all fields");
          await dialog.ShowAsync();
          return;
      }
      //check uniqueness of the barcode
  
  }
  </code></pre>
  
  <p>What should I do to prevent the alert from closing the parent ContentDialog?</p>