Data Binding in Silverlight for Windows Embedded (SWE)

Question

Can someone tell me a working example of how I should perform data binding in Silverlight for Windows Embedded (SWE). I saw a showcase , so this seems possible. And I read here that I need to implement IXRPropertyBag to make it work, but not yet find (working) instructions on how to do this.

Answer 1

I was able to get a data binding that works between the property of IsCheckedtwo elements ToggleButtonbased on the insanely bad example found in the help files that ship with CTP WCE7. I would expect to establish a data context and data bindings in XAML, but in the documentation I was asked to code it.

First you need to create a class that implements IXRPropertyBag. Then you must set the data context and data binding to the instance of this property package from the code.

I'm sorry that the code does not have a naming convention, but it is still much better than the example provided by Microsoft. It is also not as simple as it can be, but I will leave this refactoring to you.

MyPropertyBag.h:

#pragma once
#include "windows.h"
#include "XamlRuntime.h"
#include "XRCustomEvent.h"
#include "XRPtr.h"

class __declspec(uuid("3C6FFC6F-17A8-4976-B034-B4FE3BFF530A"))
MyPropertyBag : public IXRPropertyBag
{
private:
    LONG m_cRef;
    IXRCustomEvent<XRPropertyChangedCustomEventArgs, IXRPropertyBag> *pRadioEvent;
    XRThreeState RadioState;

public:
    MyPropertyBag(void);

    HRESULT STDMETHODCALLTYPE GetValue(__in const WCHAR* pstrPropertyName, __out XRValue *pValue);
    HRESULT STDMETHODCALLTYPE SetValue(__in const WCHAR* pstrPropertyName, __in XRValue *pValue);
    HRESULT STDMETHODCALLTYPE GetPropertyChangedEvent(__out IXRCustomEvent<XRPropertyChangedCustomEventArgs, IXRPropertyBag>** ppEvent);

    HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, LPVOID * ppvObj);
    ULONG STDMETHODCALLTYPE AddRef();
    ULONG STDMETHODCALLTYPE Release();
};

MyPropertyBag.cpp:

#include "StdAfx.h"
#include "MyPropertyBag.h"

extern "C" const GUID __declspec(selectany) IID_MyPropertyBag = __uuidof(IXRPropertyBag);

MyPropertyBag::MyPropertyBag(void)
{
    RadioState = XRThreeState_Unchecked;
    pRadioEvent = CreateCustomEvent<XRPropertyChangedCustomEventArgs, IXRPropertyBag>();
}

// IXRPropertyBag implementation:

HRESULT MyPropertyBag::GetValue(__in const WCHAR* pstrPropertyName, __out XRValue *pValue)
{
    HRESULT hr = E_FAIL;
    if (0 == wcscmp(pstrPropertyName, L"RadioState"))
    {
        pValue->vType = VTYPE_INT;
        pValue->IntVal = (int)RadioState;
        hr = S_OK;
    }

    return hr;
}

HRESULT MyPropertyBag::SetValue(__in const WCHAR* pstrPropertyName, __in XRValue *pValue)
{
    HRESULT hr = E_FAIL;

    if (0 == wcscmp(pstrPropertyName, L"RadioState"))
    {
        RadioState = (XRThreeState)pValue->IntVal;
        XRPropertyChangedCustomEventArgs eventArgs;
        eventArgs.PropertyName = pstrPropertyName;
        pRadioEvent->Raise(this, &eventArgs);
        hr = S_OK;
    }

    return hr;
}

HRESULT MyPropertyBag::GetPropertyChangedEvent(IXRCustomEvent<XRPropertyChangedCustomEventArgs, IXRPropertyBag>** ppEvent)
{
    *ppEvent = pRadioEvent;
    return S_OK;
}
// end of IXRPropertyBag implementation.

// IUnknown implementation:

HRESULT MyPropertyBag::QueryInterface(REFIID riid, LPVOID * ppvObj)
{
    if (!ppvObj)
        return E_INVALIDARG;

    *ppvObj = NULL;
    if (riid == IID_IUnknown || riid == IID_MyPropertyBag)
    {
        *ppvObj = (LPVOID)this;
        AddRef();
        return NOERROR;
    }

    return E_NOINTERFACE;
}

ULONG MyPropertyBag::AddRef()
{
    InterlockedIncrement(&m_cRef);
    return m_cRef;
}

ULONG MyPropertyBag::Release()
{
    ULONG ulRefCount = InterlockedDecrement(&m_cRef);
    if (0 == m_cRef)
    {
        delete this;
    }
    return ulRefCount;
}
// end of IUnknown implementation.

BindDataToControl StartDialog :

// Data bindings
XRPtr<MyPropertyBag> viewModel(new MyPropertyBag());
BindDataToControl(pTb1, viewModel);
BindDataToControl(pTb2, viewModel);

// save the exit code for WinMain
hr = m_pVisualHost->StartDialog(&uiExitCode);
SetWinMainResultCode(uiExitCode);  

BindDataToControl, DataContext :

inline void App::BindDataToControl(IXRFrameworkElement* pElement, IXRPropertyBag* pPropertyBag)
{
    // Set the binding value and source property
    XRBinding binding;
    binding.Mode = XRBindingMode_TwoWay;
    binding.Path = L"RadioState";
    pElement->SetBinding(L"IsChecked", &binding); 

    // Convert the data source object to an XRValue
    XRValue dataContext;
    dataContext.vType = VTYPE_PROPERTYBAG;
    dataContext.pPropertyBagVal = pPropertyBag;

    // Set the data source object as the data context for the option button
    pElement->SetDataContext(&dataContext);
}

Answer 2

TBoundProperty - . .

MSDN: Silverlight Windows Embedded

https://msevents.microsoft.com/CUI/WebCastEventDetails.aspx?EventID=1032474142&EventCategory=3&culture=en-US&CountryCode=US