{"action":"created","issue":{"url":"https://api.github.com/repos/Microsoft/XamlBehaviors/issues/79","repository_url":"https://api.github.com/repos/Microsoft/XamlBehaviors","labels_url":"https://api.github.com/repos/Microsoft/XamlBehaviors/issues/79/labels{/name}","comments_url":"https://api.github.com/repos/Microsoft/XamlBehaviors/issues/79/comments","events_url":"https://api.github.com/repos/Microsoft/XamlBehaviors/issues/79/events","html_url":"https://github.com/Microsoft/XamlBehaviors/issues/79","id":130512153,"number":79,"title":"Design Time Compatablility when Nesting actions in a Datatemplate UWP","user":{"login":"Chrissteven81","id":3844676,"avatar_url":"https://avatars.githubusercontent.com/u/3844676?v=3","gravatar_id":"","url":"https://api.github.com/users/Chrissteven81","html_url":"https://github.com/Chrissteven81","followers_url":"https://api.github.com/users/Chrissteven81/followers","following_url":"https://api.github.com/users/Chrissteven81/following{/other_user}","gists_url":"https://api.github.com/users/Chrissteven81/gists{/gist_id}","starred_url":"https://api.github.com/users/Chrissteven81/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Chrissteven81/subscriptions","organizations_url":"https://api.github.com/users/Chrissteven81/orgs","repos_url":"https://api.github.com/users/Chrissteven81/repos","events_url":"https://api.github.com/users/Chrissteven81/events{/privacy}","received_events_url":"https://api.github.com/users/Chrissteven81/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2016-02-01T22:58:38Z","updated_at":"2016-03-07T19:28:35Z","closed_at":null,"body":"When using attaching an Action to a uielement inside a datatemplate and viewing in xaml designer the code will throw the error Collection property '__implicit_items' is null. This would lead me to think I have to initialize behaviors/Actions collection before adding actions however, you still get the same error. The error is only thrown at design time and compiles and runs as expected.\r\n\r\nThis only occurs when the action is added to an element inside a datatemplate and it disables further designing of the template. This can be duplicated in both Visual studio and Blend.\r\n\r\nCode:\r\n`<Interactivity:Interaction.Behaviors>\r\n                <Core:EventTriggerBehavior EventName=\"Tapped\">\r\n                    <Core:NavigateToPageAction TargetPage=\"\" />\r\n                </Core:EventTriggerBehavior>\r\n            </Interactivity:Interaction.Behaviors>`\r\n\r\n\r\nAdditional Information:\r\nThis does not happen until you attempt to enter design view. so you have to click edit generated items(itemtemplate) from the document outline."},"comment":{"url":"https://api.github.com/repos/Microsoft/XamlBehaviors/issues/comments/193411175","html_url":"https://github.com/Microsoft/XamlBehaviors/issues/79#issuecomment-193411175","issue_url":"https://api.github.com/repos/Microsoft/XamlBehaviors/issues/79","id":193411175,"user":{"login":"Chrissteven81","id":3844676,"avatar_url":"https://avatars.githubusercontent.com/u/3844676?v=3","gravatar_id":"","url":"https://api.github.com/users/Chrissteven81","html_url":"https://github.com/Chrissteven81","followers_url":"https://api.github.com/users/Chrissteven81/followers","following_url":"https://api.github.com/users/Chrissteven81/following{/other_user}","gists_url":"https://api.github.com/users/Chrissteven81/gists{/gist_id}","starred_url":"https://api.github.com/users/Chrissteven81/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Chrissteven81/subscriptions","organizations_url":"https://api.github.com/users/Chrissteven81/orgs","repos_url":"https://api.github.com/users/Chrissteven81/repos","events_url":"https://api.github.com/users/Chrissteven81/events{/privacy}","received_events_url":"https://api.github.com/users/Chrissteven81/received_events","type":"User","site_admin":false},"created_at":"2016-03-07T19:28:35Z","updated_at":"2016-03-07T19:28:35Z","body":"I downloaded the solution. I found it is not a problem with xamlbehaviors, it is a bug in Visual studio undate 1. You can open 2 instances Visual studio and attach the second instance to the first instance to debug the design time methods. You will notice there is no code actually executing that would cause this."}}