Hola,
Am a .NET developer and new to C++/CX. How do you create template event handlers and delegates (generic event handlers and delegates) in C++/CX. There aren't enough examples on C++/CX Templates in MSDN.
Please help .NET developers (like me) to pitch in to C++/CX. And I love Modern Cpp and Windows Store apps.
I would appreciate if you help me with code rather than referring me to Stack Overflow etc.
This is an earnest request because "Googling with Bing" didn't help!!!
Here's the C# Code Snippet:
public sealed class BuyNow
{
public event EventHandler<StartEventArgs> Start;
public event EventHandler<AuthEventArgs> Auth;
public event EventHandler<CancelEventArgs> Cancel;
public event EventHandler<ErrorEventArgs> Error;
public event EventHandler<CompleteEventArgs> Complete;
private delegate T Generator<T>();
private void OnStart()
{
Generator<StartEventArgs> generator = () => { return new StartEventArgs(); };
Emit(generator);
}
private void OnAuth(string token)
{
Generator<AuthEventArgs> generator = () => { return new AuthEventArgs(token); };
Emit(generator);
}
private void OnCancel(string token)
{
Generator<CancelEventArgs> generator = () => { return new CancelEventArgs(token); };
Emit(generator);
}
private void OnError(ErrorType type, string name, string message)
{
OnError(type, name, message, null);
}
private void OnError(ErrorType type, string name, string message, string detail)
{
Generator<ErrorEventArgs> generator = () => { return new ErrorEventArgs(type, name, message, detail); };
Emit<ErrorEventArgs>(generator);
}
private void OnComplete(string token, string transactionId, string payerId)
{
Generator<CompleteEventArgs> generator = () => { return new CompleteEventArgs(token, transactionId, payerId); };
EmitAndComplete<CompleteEventArgs>(generator);
}
private void EmitAndComplete<T>(Generator<T> generator)
{
}
private void Emit<T>(Generator<T> generator)
{
TypeInfo info = this.GetType().GetTypeInfo();
TypeInfo genericType = typeof(T).GetTypeInfo();
// Get all the available events
foreach (EventInfo eventInfo in info.DeclaredEvents)
{
// Get the type arguments for the current event (really, there should only be one)
Type[] typeParameters = eventInfo.EventHandlerType.GetTypeInfo().GenericTypeArguments;
foreach (Type parameterType in typeParameters)
{
// If the type parameter matches the type we're trying to emit...
if (parameterType.GetTypeInfo().IsAssignableFrom(genericType))
{
// Get the field of the same name so we can access the token table
FieldInfo eventField = info.GetDeclaredField(eventInfo.Name);
EventRegistrationTokenTable<EventHandler<T>> tokenTable = eventField.GetValue(this) as EventRegistrationTokenTable<EventHandler<T>>;
if (tokenTable != null)
{
// Events are registered, so generate our event args, invoke, and break out
EventHandler<T> handler = tokenTable.InvocationList;
T eventArgs = generator();
handler.DynamicInvoke(new object[] { this, eventArgs });
goto complete;
}
}
}
}
complete: { }
}
}
public enum ErrorType
{
UNKNOWN = 0,
HTTP = 1,
API = 2,
NETWORK = 3
}
public sealed class StartEventArgs
{
}
public sealed class AuthEventArgs
{
public string Token { get; private set; }
public AuthEventArgs(string token)
{
Token = token;
}
}
public sealed class CancelEventArgs
{
public string Token { get; private set; }
public CancelEventArgs(string token)
{
Token = token;
}
}
public sealed class ErrorEventArgs
{
public ErrorType Type { get; private set; }
public string Code { get; private set; }
public string Message { get; private set; }
public string Detail { get; private set; }
public ErrorEventArgs(ErrorType type, string name, string message, string detail)
{
Type = type;
Code = name;
Message = message;
Detail = detail;
}
}
public sealed class CompleteEventArgs
{
public string Token { get; private set; }
public string TransactionID { get; private set; }
public string PayerID { get; private set; }
public CompleteEventArgs(string token, string transactionId, string payerId)
{
Token = token;
TransactionID = transactionId;
PayerID = payerId;
}
}
Referring to MSDN
http://msdn.microsoft.com/en-us/library/windows/apps/hh755799.aspx:
I tried the following:
ref class BuyNow;
public delegate void EventHandler(BuyNow^ sender, Platform::String^ s);
public ref class BuyNow sealed
{
private:
static const Uri^ PROXY_URI;
static const Uri^ SANDBOX_PROXY_URI;
Boolean buyNowUseSandbox;
Boolean buyNowHasError;
Purchase^ purchaseRequest;
public:
BuyNow(String^ merchantID);
virtual ~BuyNow(void);
BuyNow(){}
event EventHandler^ Start;
event EventHandler^ Auth;
event EventHandler^ Cancel;
event EventHandler^ Error;
event EventHandler^ Complete;
void OnStart()
{
//Do something....
// ...then fire the event:
Start(this, L"Event Started.");
}
void OnAuth()
{
//Do something....
// ...then fire the event:
Auth(this, L"Event Authorized.");
}
void OnCancel()
{
//Do something....
// ...then fire the event:
Cancel(this, L"Event Cancelled.");
}
void OnError()
{
//Do something....
// ...then fire the event:
Error(this, L"Event Error.");
}
void OnComplete()
{
//Do something....
// ...then fire the event:
Complete(this, L"Event Completed.");
}
};
public enum class ErrorType
{
UNKNOWN = 0,
HTTP = 1,
API = 2,
NETWORK = 3
};
public ref class StartEventArgs sealed
{
};
public ref class AuthEventArgs sealed
{
private:
String^ authEventArgsToken;
public:
AuthEventArgs(String^ token)
{
Token = token;
}
property String^ Token
{
String^ get()
{
return authEventArgsToken;
}
void set(String^ value)
{
authEventArgsToken = value;
}
}
};
public ref class CancelEventArgs sealed
{
private:
String^ cancelEventArgsToken;
public:
CancelEventArgs(String^ token)
{
Token = token;
}
property String^ Token
{
String^ get()
{
return cancelEventArgsToken;
}
void set(String^ value)
{
cancelEventArgsToken = value;
}
}
};
public ref class ErrorEventArgs sealed
{
private:
ErrorType errorEventArgsType;
String^ errorEventArgsCode;
String^ errorEventArgsMessage;
String^ errorEventArgsDetail;
public:
ErrorEventArgs(ErrorType type, String^ name, String^ message, String^ detail)
{
Type = type;
Code = name;
Message = message;
Detail = detail;
}
property ErrorType Type
{
ErrorType get()
{
return errorEventArgsType;
}
void set(ErrorType value)
{
errorEventArgsType = value;
}
}
property String^ Code
{
String^ get()
{
return errorEventArgsCode;
}
void set(String^ value)
{
errorEventArgsCode = value;
}
}
property String^ Message
{
String^ get()
{
return errorEventArgsMessage;
}
void set(String^ value)
{
errorEventArgsMessage = value;
}
}
property String^ Detail
{
String^ get()
{
return errorEventArgsDetail;
}
void set(String^ value)
{
errorEventArgsDetail = value;
}
}
};
