How about this workaround? private Action<string, object[]> writeToLogCallBack; public void WriteToLogCallBack(string s, params object[] args) { if(writeToLogCallBack!=null) writeToLogCallBack(s,args); } Or you could define your own delegate type: delegate void LogAction(string s, params object[] args);
You need to use delegates and the BeginInvoke method that they contain to run another method asynchronously. A the end of the method being run by the delegate, you can notify the user. For example: class MyClass { private delegate void SomeFunctionDelegate(int param1, bool param2); private SomeFunctionDelegate sfd; public MyClass() { sfd = new SomeFunctionDelegate(this.SomeFunction); … Read more
You will want to declare a delegate protocol for your class. An example of a delegate protocol and interface for class Foo might look like this: @class Foo; @protocol FooDelegate <NSObject> @optional – (BOOL)foo:(Foo *)foo willDoSomethingAnimated:(BOOL)flag; – (void)foo:(Foo *)foo didDoSomethingAnimated:(BOOL)flag; @end @interface Foo : NSObject { NSString *bar; id <FooDelegate> delegate; } @property (nonatomic, retain) … Read more
DelegatedCall expects a delegate that takes any object as an argument. But your function foo1 that you are passing to DelegatedCall can only cope with a string argument. So, the conversion isn’t type-safe and thus is not possible. Input parameters are contra-variant, but your code needs covariance. (See Difference between Covariance & Contra-variance.) You can … Read more
You’re using a method group conversion to create the Func<long, long, bool> used for the comparerFunc parameter. Unfortunately, the C# 5 specification currently requires that to create a new delegate instance each time it’s run. From the C# 5 specification section 6.6, describing the run-time evaluation of a method group conversion: A new instance of … Read more
No, you cannot have a delegate as an attribute constructor parameter. See available types: Attribute parameter types As a workaround (although it’s hacky and error prone) you can create a delegate with reflection: [AttributeUsage(AttributeTargets.Class | AttributeTargets.Interface, AllowMultiple = false, Inherited = true)] public class WorkspaceAttribute : Attribute { public ConnectionPropertiesDelegate ConnectionDelegate { get; set; } … Read more
There’s a much simpler way to do it, which all the other answers have missed: Func<int, int> c = a.Invoke; See this blog post for more info.
respondsToSelector: is part of the NSObject protocol. Including NSObject in MyProtocol should solve your problem: @protocol MyProtocol <NSObject> @optional -(void)optionalProtocolMethod:(id)anObject; @end
Delegate.EndInvoke is documented as a thou shalt call this (i.e. necessary – else leaks happen) – from msdn: Important Note No matter which technique you use, always call EndInvoke to complete your asynchronous call. Control.EndInvoke is OK to ignore for fire-and-forget methods – from msdn: You can call EndInvoke to retrieve the return value from … Read more
Changing functionality at runtime is not what delegates accomplish. Basically, delegates save you a crapload of typing. For instance: class Person { public string Name { get; } public int Age { get; } public double Height { get; } public double Weight { get; } } IEnumerable<Person> people = GetPeople(); var orderedByName = people.OrderBy(p … Read more