I have defined a delegate like this:
delegate void processRecord(int a, int b);
now i want to use that to create an anonymous method to supply in a function call. The function is defined as such:
void someFunction(processRecord fcn);
and I want to call someFunction with an anonymous method, but this I cannot get right:
someFunction(new processRecord(a, b) {
// do stuff
});
How is the correct syntax for something like this?
The correct syntax to declare the call to method with processRecord parameter is:
someFunction(delegate (int a, int b) {
// use a and b here
});
You can take advantage of lambda syntax invoking your someFunction, because processRecord is compatible with Action<int,int>, like this:
someFunction((a, x) => Console.WriteLine(a + "; " + x));
But in .net framework there already exist generic delegate Action since .NET 3.5, which you can use instead of creating your own.
So instead you can simply define your function as
void someFunction(Action<int, int> fcn) {}
then call
someFunction( (a,b) => /*use a and b here*/ );
Action to use a lambda, you can use that lambda, exactly as you have there, with the delegate he's currently using.
Action<...> delegates were introduced by .Net 3.5.You can call it like this:
someFunction(delegate( int a, int b) {
// do stuff
});
C# compiler will figure out that you are making a delegate processRecord from the context of the call.
You can use it if you use deletegate in your someFunction
someFunction(delegate( int a, int b) {
// do some stuff
});
Here is a DEMO.
processRecord t = (q,w) =>
{
int n = q+w;
};
someFunction(t);
Here are some options, all of which do effectively the same thing:
someFunction((a,b) => DoStuff());
someFunction(delegate(int a, int b){ doStuff(); });
someFunction(new processRecord((int a, int b) =>
{
doStuff(); doMoreStuff();
}));
someFunction((a,b) => { doStuff(); });
processRecorddelegate anywhere else? Is not - useActionsomeFunction((a, b) => /* a and b usage*/);