KeyDown Event is not working

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Hi All,
Please see my below code(I am trying to make a snake game).But its found that the keydown event is not working.

public partial class Form1 : Form
    {
        Button Head = null;
        string Direction = "R";
        public Form1()
        {
            InitializeComponent();
            this.KeyPreview = true;
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            Button btn = new Button();
            btn.BackColor = Color.Red;
            btn.Text = "";
            btn.Size = new Size(12, 12);
            btn.Location = new Point(10, 10);
            Head = btn;
            this.Controls.Add(Head);
            MoveTimer.Start();
        }

        private void MoveTimer_Tick(object sender, EventArgs e)
        {
            MoveSnake();
        }

        private void MoveSnake()
        {
            switch (Direction)
            {
                case "R" :
                    Head.Location = new Point(Head.Location.X + 1, Head.Location.Y);
                    break;
                case "L":
                    Head.Location = new Point(Head.Location.X - 1, Head.Location.Y);
                    break;
                case "U":
                    Head.Location = new Point(Head.Location.X , Head.Location.Y -1);
                    break;
                case "D":
                    Head.Location = new Point(Head.Location.X, Head.Location.Y + 1);
                    break;
            }
        }

        private void Form1_KeyDown(object sender, KeyEventArgs e)
        {
            switch (e.KeyCode)
            {

                case Keys.Down:
                    Direction = "D";
                    break;

                case Keys.Left:
                    Direction = "L";
                    break;

                case Keys.Right:
                    Direction = "R";
                    break;


                case Keys.Up:
                    Direction = "U";
                    break;

            }
        }
    }

Please Anyone can help me on this....

Posted 14-Dec-14 19:43pm

Manu Prasad

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Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 15-Dec-14 1:52am

Have you debugged? Is it going inside the event?

Manu Prasad 15-Dec-14 1:53am

No, its not going inside the event.

BillWoodruff 15-Dec-14 2:01am

You put a break-point on the line switch (e.KeyCode) and you run your app and press one of the arrow-keys ... and it never reaches that break-point ?

Tadit Dash (ତଡିତ୍ କୁମାର ଦାଶ) 15-Dec-14 3:34am

Are you sure, you have assigned the event to the form. Check form properties.

Manu Prasad 15-Dec-14 1:56am

Hi all I just disabled the button then its working. Can Anyone tell why?

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Marcin Kozub · Answer 1 · 2014-12-14T20:17:00

Hi,

To handle arrow keys, ESC, TAB, RETURN you must override IsInputKey method. More informations you can find here:
http://msdn.microsoft.com/en-us/library/system.windows.forms.control.keydown%28v=vs.110%29.aspx[^]

Instead of using KeyDown event you can override Form's ProcessCmdKey method. This should do the trick:

C#

protected override bool ProcessCmdKey(ref Message msg, Keys keyData)
{
    if (keyData == Keys.Down)
    {
        Direction = "D";
        return true;
    }
    else if (keyData == Keys.Left)
    {
        Direction = "L";
        return true;
    }
    else if (keyData == Keys.Right)
    {
        Direction = "R";
        return true;
    }
    else if (keyData == Keys.Up)
    {
        Direction = "U";
        return true;
    }
    return base.ProcessCmdKey(ref msg, keyData);

}

Cheers!

Kornfeld Eliyahu Peter · Answer 2 · 2014-12-14T20:12:00

You probably have a focus problem...
The button you have on the for holds the focus, so any key event goes to it and your window gets nothing...
Try this:
Create a panel as you area of the game (and not the whole window client area), set the focus on that panel upon start...Now key events will go to that panel, so add your event handler to the panel...

KeyDown Event is not working

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