Programmiererforum

Code: Select all

_receiver = (IStateReceiver)new StateReceiver();
< /code>
Mit dem Fehler lautet: < /p>

Der Typ 't' kann im generischen Typ oder in der Methode 'Stveseciver ' nicht als Typparameter 't' verwendet werden. Es gibt keine Konvertierung oder Typ-Parameterkonvertierung von Boxen von 't' zu 'state.istatereceiver '. unten mit einem Beispielverbrauch: < /p>
 public interface IStateCommand
{
Task ExecuteAsync();
}

public interface IStateReceiver
{
Task RunCommand(Y command);
}

public sealed class StateCommand  : IStateCommand
{
private IStateReceiver _receiver;
private Y _command;
private StateCommand() {  /* no body */ }

public static Task CreateAsync(Y command)
{
var ret = new StateCommand();
return ret.Initialize(command);
}

public async Task Initialize(Y command)
{
_command = command;
_receiver = (IStateReceiver)new StateReceiver();

await Task.Delay(1000);
return this;
}

public async Task ExecuteAsync()
{
return await this._receiver.RunCommand(this._command);
}
}

// Example receiver.
public class StateReceiver where T: IStateReceiver,  new()
{
public async Task RunCommand(Y command)
{
// Perform action here.
await Task.Delay(1000);

// Can be simple type e.g. int or complex eg BobsResultObject. Just returning default here for now.
return new T();
}
}

// Example invoke
public class StateInvoker
{
public async void PerformCommand()
{
String command = "BobsCommand";
StateCommand bobsCommandObject = await StateCommand.CreateAsync(command);
var bobsResult = bobsCommandObject.ExecuteAsync();
}
}

Code: Select all

private async Task Initialize(Y command)
{
_command = command;

if (typeof(Y) == typeof(string))
{
String localCommand = command as String;

if (localCommand != null)
{
switch (localCommand.ToLower())
{
case "bobscommand":
_receiver = new StateReceiver() as IStateReceiver;
break;
}
}
}

return this;
}
< /code>
Und hier ist der Empfänger ohne Schnittstelle (und eine grundlegende Zuordnung) < /p>
public class StateReceiver where T : new()
{
public async Task RunCommand(Y command)
{
// Perform action here.
await Task.Delay(1000);

T t = new T();

if (typeof(T) == typeof(int))
t = (T)(object)42;
else
t = (T)(object)null;

return t;
}
}

Code: Select all

public class StateReceiver : IStateReceiver where T : new() where Y : class
{
public async Task RunCommand(Y command)
{
// Perform action here.
await Task.Delay(1000);

T t = new T();

if (typeof(T) == typeof(int))
t = (T)(object)42;
else
t = (T)(object)null;

return t;
}
}

Code: Select all

 public interface IStateReceiver where T : new() where Y :  class
{
Task RunCommand(Y command);
}
< /code>
Und dann kann die Initialize (Factory -Methode) auf folgende (Beispiel) erweitert werden < /p>
private async Task
> Initialize(Y command)
{
_command = command;

var tokenSource = new CancellationTokenSource();
var token = tokenSource.Token;

await Task.Run(() =>
{
if (typeof(Y) == typeof(string))
{
String localCommand = command as String;
if (localCommand != null)
{
switch (localCommand.ToLower())
{
case "bobscommand":
_receiver = new StateReceiver() as IStateReceiver;
break;
}
}
}
}, token);

return this;
}