Use of Xaml DataTemplates

Question

I have defined a popup in the code-behind of a ContentPage with a DataTemplate as follows: popUpLayout.PopupView.ContentTemplate = (DataTemplate)Resources["PopUpTestTemplate"];and then in the ResourceDictionary of the ContentPage like this: On UWP this renders correctly, with the frames, images and labels displayed.On iOS however, the frames are rendered, but the content - the image and the label are not displayed.I have tried various combinations of elements, but cannot get the content to show on iOS. Can you please provide an example showing this type of layout defined in a DataTemplate in XAML.

Peter Mortley · Answer

Just to note this is on version 16.1.0.32

Suhasini Suresh · Answer

Hi Peter, 
 
Thanks for contacting Syncfusion Support. 
 
We checked your query and we are able to reproduce the issue “On iOS the content is not displayed”. We have a logged a bug report for the same and the reported issue will be fixed in the upcoming release. As of now, you can overcome the issue in the sample level, by removing the HorizontalOptions and VerticalOptions set to the content in the DataTemplate.  
 
We have prepared a sample to achieve your requirement, you can download the same from the below link: 
Sample Link: http://www.syncfusion.com/downloads/support/forum/136759/ze/GettingStarted1068409125  
 
Regards, 
Suhasini

Peter Mortley · Answer

I have retested this with version 16.1.0.37, and the problem still exists on iOS.

Suhasini Suresh · Answer

Hi Peter, 
 
Sorry for the inconvenience caused. The fix for the reported issue is not included in the release with version 16.1.0.37. The fix will be included in 2018 Volume 2 main release which will be rolled out by the last week of May 2018.  
 
Let me know whether you require the custom assemblies for the reported issue. 
 
Regards, 
Suhasini

Peter Mortley · Answer

Having updated the SfPopup component from 16.1.037 to 16.2.0.42, I am now getting a crash. This is both on UWP and iOS.

I am setting a popup in the code-behind of a ContentPage with a DataTemplate as follows:

popUp.PopupView.ContentTemplate = (DataTemplate)Resources["VRErrorTemplate"];

In the ResourceDictionary of the ContentPage I have defined the template

This works in 16.1.037

FYI I also have some other shared templates within a MergedDictionary on this ContentPage.

<ResourceDictionary.MergedDictionaries>

<local:SequenceUpPopUp />

</ResourceDictionary.MergedDictionaries>

These popups can still be displayed correctly.

After upgrading to 16.2.0.42, I get the error below when attempting to set the ContentTemplate

System.NullReferenceException

HResult=0x80004003

Message=Object reference not set to an instance of an object.

Source=Syncfusion.SfPopupLayout.XForms.UWP

StackTrace:

at Syncfusion.XForms.UWP.PopupLayout.PopupLayoutDependencyService.MapPopupViewProperties(String propertyName)

at Syncfusion.XForms.PopupLayout.PopupView.OnContentTemplatePropertyChanged(BindableObject bindable, Object oldValue, Object newValue)

at Xamarin.Forms.BindableObject.SetValueActual(BindableProperty property, BindablePropertyContext context, Object value, Boolean currentlyApplying, SetValueFlags attributes, Boolean silent)

at Xamarin.Forms.BindableObject.SetValueCore(BindableProperty property, Object value, SetValueFlags attributes, SetValuePrivateFlags privateAttributes)

at Xamarin.Forms.BindableObject.SetValue(BindableProperty property, Object value, Boolean fromStyle, Boolean checkAccess)

at Syncfusion.XForms.PopupLayout.PopupView.set_ContentTemplate(DataTemplate value)

at SBSV5X.Views.NamingView.ShowVRError() in C:\Data\Development\SBSV5\SBSV5XRepo\SBSV5X-Syncfusion\SBSV5X\SBSV5X\Views\NamingView.xaml.cs:line 281

at SBSV5X.Views.NamingView.<OnAppearing>b__12_4(NamingViewModel NamingViewModel) in C:\Data\Development\SBSV5\SBSV5XRepo\SBSV5X-Syncfusion\SBSV5X\SBSV5X\Views\NamingView.xaml.cs:line 113

Peter Mortley · Answer

I have replicated this for you.Taking the 'Getting Started' sample that you sent me previously as a starting point, I have:1) Upgraded to Xamarin forms 2.5.1.527436 (To support merged dictionaries)2) Used SfPopupLayout 16.2.0.423) Added a simple merged dictionary.If you run the included solution and press the 'relativePopup' button, the popup will work from the merged dictionary.If you press the "Show Popup" button you will see the error described above.If you downgrade to SfPopupLayout 16.1.0.37, then both buttons will work!Attachment: GettingStarted_677b8e33.zip

Sivakumar R · Answer

Hi Peter,

            

Thanks for
your update.

 

We are able
to reproduce the reported issue ” Exception occurs when switching
ContentTemplate via Merged Dictionaries (Xamarin.Forms.2.5.1.527436) when Displaying
pop-up when the SfPopupLayout is not set as root view” and we have logged
the bug report for the same. The fix for the reported issue will be included in
2018 Volume 2 service pack 1 release which is expected to available by end of
July, 2018.

 

In meantime,
You can overcome the issue in sample level by Displaying
pop-up when the SfPopupLayout is set as root view. We have modified the
sample by displaying popup when SfPopupLayout is set as the root view to fix
the issue, you can download the same from the below link.

 

Please find
the modified code changes in the below code snippet for fixing the issue in
sample level.


 
  
  public MainPage()
  {
      InitializeComponent();
      . . . . 
      . . . .
     // Change made for Displaying popup when the SfPopupLayout is
  set as root view
      popupLayout.Content = stackLayout;
      this.Content = popupLayout;
  }
  
 


 

Sample
Link: http://www.syncfusion.com/downloads/support/forum/136759/ze/UpdateSample-2039889506


 

Regards,

Siva

Peter Mortley · Answer

Thank-you for your response. The SfPopup is proving to be a great control for my UI, and I have implemented multiple use-cases. I have tested the sample that you have attached.

I have complex screens with the layout designed in XAML, with no code-behind layout. There would be significant work to try and implement the work-around.

Can you please let me have pre-release code as soon as it is available to test please?

Suhasini Suresh · Answer

Hi Peter, 
 
We have created an incident for you under your account for this query, so please follow up with this query in the incident created for you. 
 
Regards, 
Suhasini