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I have 2 questions.

  1. The first main question is how do I fix the error I have when trying to invoke the method that contain KeyEventArgs e as argument. I only know how to deal with arguments when they are variables.

  2. The Second is just a quick question if the while loop will do so the program wait for (keydown) before printing the text(label) 

    namespace Test2014
{
    public partial class Form1 : Form
    {
        List<Action> methods = new List<Action>();

        public Form1()
        {
            InitializeComponent();

            // 1. Error invalid arguments
            methods.Insert(0, test); // 1.  passing ( KeyEventArgs e ) as argument ?

        }

        private void button1_Click(object sender, EventArgs e)
        {
            methods[0].Invoke();

        }


        void test(KeyEventArgs e) // 1. passing ( KeyEventArgs e ) as argument ?
        {          
            while (true) 
            {

                if (e.KeyCode == Keys.A)  // 2. do this work as wait for keydown before moving down ?
                    break;

            } // 2.
            label_test.Text = "When Loop is broken (key down(A)) change this label";
        }
    }
}
mollmerx
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  • Don't use `while (true)` in the event handler. It will loop indefinitely unless the right key is pressed. – D Stanley Apr 24 '14 at 15:09
  • @DStanley Isn't that the point? – Ben Aaronson Apr 24 '14 at 15:11
  • @BenAaronson I think D Stanley meant by that that an event driven approach might be better. From my experience such loops will take at least 50% CPU time even if there's nothing to be processed in it other than this if block. – Francis Ducharme Apr 24 '14 at 15:13
  • @FrancisDucharme Yeah, I was assuming this was more of a toy example than anything else, but I guess it *is* worth emphasising that it's not a good approach in a real application – Ben Aaronson Apr 24 '14 at 15:15
  • Can we have the definition of `test` that you are trying to add to the list and later call its `Invoke` method? – Francis Ducharme Apr 24 '14 at 15:19
  • @BenAaronson If `test` is called and passed a key _other_ than "A" the function will loop indefinitely and the program will "hang". The OP seems to think that he/she is setting up a "message loop" that will infinitely loop and only respond if the right key is pressed. That's not what's happening here - control is never passed back to the calling method. – D Stanley Apr 24 '14 at 15:27

0 Answers0