tl;dr: Write an out(n) function rather than out1(), out2(), …, outN() and don’t bother with this hack. I cannot imagine a reasonable scenario where this question would come up in practice. Please reconsider the architecture of the problem; there is likely to be a much better way to do this (because storing them in a … Read more
You’re trying to create a delegate from an instance method, but you’re not passing in a target. You could use: Delegate.CreateDelegate(typeof(TestDelagate), this, method); … or you could make your method static. (If you need to cope with both kinds of method, you’ll need to do that conditionally, or pass in null as the middle argument.)
As Peter Ritchie suggested, you can compile your own code at runtime. The method will be compiled as soon as you invoke the delegate for the first time. So the first call will be slow, but any subsequent call will be as fast as you can get in .NET without unmanaged pointers/unions. Except for the … Read more
One way to think about a delegate is like a reference to a function. For example, say you have a button in a window, and you want something to happen when the button is clicked. You can attach a delegate to the Click event of the button, and whenever the user clicks this button, your … Read more
Although you can make a call into a delegate which will be handled by a separate AppDomain, I personally have always used the ‘CreateInstanceAndUnwrap’ method which creates an object in the foreign app domain and returns a proxy to it. For this to work your object has to inherit from MarshalByRefObject. Here is an example: … Read more
Create your own delegate type: delegate void MyAction(ref DataRow dataRow, double doubleValue); And use MyAction in place of Action<ref DataRow, Double> — which, as you’ve noted, doesn’t compile.
Delegating is a good programming practice for many situations but that doesn’t mean you have to use it if you’re not comfortable with it. Both delegating and notifications help decouple the view controllers from each other, which is a good thing. Notifications might be a little easier to code and offer the advantage that multiple … Read more
Easy! Since here is the implementation of the GetHashCode (sitting on the base class Delegate): public override int GetHashCode() { return base.GetType().GetHashCode(); } (sitting on the base class MulticastDelegate which will call above): public sealed override int GetHashCode() { if (this.IsUnmanagedFunctionPtr()) { return ValueType.GetHashCodeOfPtr(base._methodPtr); } object[] objArray = this._invocationList as object[]; if (objArray == null) … Read more
What is the advantage of using the event keyword other than for modifying how the delegate can be accessed? That is the primary advantage of using the event keyword. You use an event over just a raw delegate to prevent the delegate from being invoked or cleared from outside the scope of the class it … Read more
Optional parameters are an attribute of a method or delegate parameter. When you call a signature (method or delegate) that has a known optional parameter at compile-time, the compiler will insert the optional parameter value at the callsite. The runtime is not aware of optional parameters, so you can’t make a delegate that inserts an … Read more