Windows Phone 8.1 ManipulationDelta Event

Question

I'm really confused about this Topic. None of the tutorials I found to eg move objects around when there's touch input works. For example they all do something like this:

Control.AddHandler(UIElement.ManipulationStartedEvent, new EventHandler
    <ManipulationStartedEventArgs>(Control_ManipulationStarted), true);

But there's no ManipulationStartedEventArgs, VS2013 can't find it and there's no way to add a using directive. Are those tutorials old and did MS change the way the ManipulationDelta works?

Adding it with the EventHandler section of the Properties section again doesn't work, no Event is fired no matter what I'm trying to do.

Answer 1

For manipulation to work the UI Element must have ManipulationMode property set to something other than None or System to be a manipulation event source; ie Set ManipulationMode to TranslateX if you want an event to fire on a horizontal pointer movement.

For UI manipulation in Windows Universal you have 3 events:

• ManipulationStarted
• ManipulationDelta
• ManipulationCompleted

Each with their own EventArgs under System.Windows.Input namespace

• ManipulationStartedEventArgs
• ManipulationDeltaEventArgs
• ManipulationCompletedEventArgs

The problem may however be the type of UI Element that you are using, not all accept/generate manipulation events.

Examples of UI Elements that don't:

• WebView
• (I expect Canvas but not sure, haven't tested)

Examples of UI Elements that do:

• Textblock
• ListView