Consuming events in javascript

Question

Hi,

I am using javascript to write a metro style application. It has a winRT component written in C++. The component provides a event whose signature is:

public delegate void EventHandler(Platform::String^ path, Windows::Foundation::Collections::IMap<String^, Windows::Foundation::PropertyValue^> ^userData);

How can I consume this event in javascript?

I tried the following code:

var jseventHandler = function (arg1) {};
nativeObject.onsomeevent = jseventHandler;

and also:

var jseventHandler = function (arg1, arg2) {};
nativeObject.onsomeevent = jseventHandler;

But, either way it does not work and I get the following error:

0x800a13e3 - JavaScript runtime error: The function 'jseventHandler' has an invalid signature and cannot be called.

Please Help.

Answer 1

Hi Nick,

This documentation covers handling events in Javascript from a Native component:

http://msdn.microsoft.com/en-us/library/windows/apps/hh441569(v=vs.110).aspx

Jeff

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Jeff Sanders (MSFT)

Answer 2

Hi Jeff,

Thanks fir replying. I have already gone through that link several times but it does not help. It only describes an event handler for a particular case.

In my case, the delgate has a map which takes PropertyValue as its value type. If I change it to "String", then everything works fine. Therefore, I doubt it does not work in the [particular case where the value type is PropertyValue in IMap, may be because Javascript is not able to instantiate such kind of maps when called through events. It might be a bug in VS 2012 or WinRT.

Please help.

Thanks in advance.