Objective-C code blocks equivalent in C#

Question

How would I write the equivalent code in C#:

typedef void (^MethodBlock)(int); 

- (void) fooWithBlock:(MethodBlock)block
{
    int a = 5;
    block(a);
}

- (void) regularFoo
{
    [self fooWithBlock:^(int val) 
    {
        NSLog(@"%d", val);
    }];
}

Answer 1

Something like this:

void Foo(Action<int> m)
{
    int a = 5;
    m(a);
}

void RegularFoo()
{
    Foo(val => // Or: Foo(delegate(int val)
    {
        Console.WriteLine(val);
    });
}

Action<T> is a delegate that takes exactly one argument of a type you specify (in this case, int), that executes without returning anything. Also see the general C# delegate reference.

For a simple case like this, it's pretty straightforward. However, I believe there are some semantic/technical differences between blocks in Objective-C and delegates in C#, which are probably beyond the scope of this question.

Answer 2

void fooWithBlock(Action<int> block)
{
   int a = 5;
   block(a);
}