C#

Josh Smith wrote:

You were only returning a value at the bottom of the try block.

Josh Smith wrote:

can't modify an event handler's signature anywa

leckey wrote:

So how do I actually fix this so I can access the value outside of btnAdd_Click?

Christian Graus wrote:

he easiest way to do this may well be to create a tree control that is never shown on a form, and populate it.

Josh Smith wrote:

(no offense to you, Christian).

Josh Smith wrote:

If you don't need a control, don't use one, it's really expensive.

Christian Graus wrote:

I would not regard the overhead to be that much, certainly compared to the overhead of writing a tree structure, assuming one can't be found to use. But, like I said, I'm not claiming to always be right

Christian Graus wrote:

certainly compared to the overhead of writing a tree structure

class Tree
{
    private int value = 0;

    public Tree leftChild = null;
    public Tree rightChild = null;

    public Tree(int value) { this.value = value; }
}

Tree root = new Tree(123);
root.leftChild = new Tree(5);
root.rightChild = new Tree(411);

public class Tree {
    private Tree parent;
    private List<Tree> children;

    public Tree Parent {
        get { return parent; }
        set { parent = value; }
    }

    public List<Tree> Children {
        get { return children; }
        set { children = value; }
    }
}

private void picBox_MouseDown(object sender, MouseEventArgs e)
{
   downX = e.X;
   downY = e.Y;
   vertValue = pnl.VerticalScroll.Value;
   horizValue = pnl.HorizontalScroll.Value;
   inMove = true;
}

private void picBox_MouseMove(object sender, MouseEventArgs e)
{
   if (inMove)
   {
      int diffX = e.X - downX;
      int diffY = e.Y - downY;

      pnl.VerticalScroll.Value = vertValue + diffX;
      pnl.HorizontalScroll.Value = horizValue + diffY;
   }
}

private void picBox_MouseUp(object sender, MouseEventArgs e)
{
   inMove = false;
}

public class ScrollablePicture {
    
    private Point m_CursorOffset;
    private int m_CurrentHScroll;
    private int m_CurrentVScroll;
    private bool m_Scrolling = false;
    
    public ScrollablePicture() {
        //  This call is required by the Windows Form Designer.
        InitializeComponent();
        //  Add any initialization after the InitializeComponent() call.
        this.Cursor = Cursors.Hand;
    }
    
    public Image Image {
        get {
            return PictureBox1.Image;
        }
        set {
            if (value != null) {
                PictureBox1.Size = value.Size;
                PictureBox1.Image = value;
            }
        }
    }
    
    private void PictureBox1_MouseDown(object sender, System.Windows.Forms.MouseEventArgs e) {
        if ((e.Button == Windows.Forms.MouseButtons.Left)) {
            m_CursorOffset = Panel1.PointToClient(System.Windows.Forms.Cursor.Position);
            m_CurrentHScroll = Panel1.HorizontalScroll.Value;
            m_CurrentVScroll = Panel1.VerticalScroll.Value;
            m_Scrolling = true;
        }
    }
    
    private void PictureBox1_MouseMove(object sender, System.Windows.Forms.MouseEventArgs e) {
        if (m_Scrolling) {
            Point Offset = Panel1.PointToClient(System.Windows.Forms.Cursor.Position);
            int newH = (m_CurrentHScroll 
                        + (m_CursorOffset.X - Offset.X));
            int newV = (m_CurrentVScroll 
                        + (m_CursorOffset.Y - Offset.Y));

            // I hate generating tons of ArgumentOutOfRange exceptions for no
            // good reason, so we'll just make sure that the new scroll values are good.
            if ((newH < Panel1.HorizontalScroll.Minimum)) {
                newH = Panel1.HorizontalScroll.Minimum;
            }
            else if ((newH > Panel1.HorizontalScroll.Maximum)) {
                newH = Panel1.HorizontalScroll.Maximum;
            }
            if ((newV < Panel1.VerticalScroll.Minimum)) {
                newV = Panel1.VerticalScroll.Minimum;
            }
            else if ((newV > Panel1.VerticalScroll.Maximum)) {
                newV = Panel1.VerticalScroll.Maximum;
            }
            Panel1.HorizontalScroll.Value = newH;
            Panel1.VerticalScroll.Value = newV;
        }
    }
    
    private void PictureBox1_MouseUp(object sender, System.Windows.Forms.MouseEventArgs e) {
        m_Scrolling = false;
    }
}