Question

I have a boolean function which is used in the decision-making of many other functions. And every time, the user is either given a message box or allowed to proceed, depending on the return value of that function. So my pseudo-code might look like this:

private bool IsConsented()
{
    //some business logic
}

private void NotReal()
{
    if (IsConsented())
    {
        //call function A
    }
    else
    {
        MessageBox.Show("Need consent first.");
    }
}

private void NotReal2()
{
    if (IsConsented())
    {
        //call function B
    }
    else
    {
        MessageBox.Show("Need consent first.");
    }
}

I am looking for a simpler way to do this, rather than hard-coding that if-else logic into every single function of mine. I’d like to be able to have a function like:

private void CheckConsent(function FunctionPointer)
        {
            if (IsConsented())
            {
                //call the function
                FunctionPointer();
            }
            else
            {
                MessageBox.Show("Need consent first.");
            }
        }

So that I can just pass a pointer to a function. I have a real suspicion that this has to do with delegates, but I don’t know the syntax, and I don’t understand how to pass parameters around using delegates.

Answer 1

You need to declare the delegate (or use a built-in one, such as Action):

 private void CheckConsent(Action action)
 {
        if (IsConsented())
        {
             action();
        }
        else
        {
            MessageBox.Show("Need consent first.");
        }
 }

You could then do:

 private void NotReal()
 {
      this.CheckConsent( () =>
      {
          // Do "NotReal" work here...
      });
 }