I want to set limit scrolling to a scrollable panel

Question

I made a scrollable panel like this:

private void button3_Click(object sender, EventArgs e)
{
    Form f2 = new Form();
    f2.Size = new Size(400, 300);
    f2.         


        

Answer 1

Tweak this method: you need to "pin" the panel so it doesn't move below the top and above the bottom - because mouse wheel deltas are events you will continuously receive. You have to manually decide when to ignore them

private void panel1_MouseWheel(object sender, MouseEventArgs e)
{
        Form2 frm = new Form2();
        panel1.Top += e.Delta > 0 ? 10 : -10;

        // tweak this
        if (panel1.Top > 0) panel1.Top = 0;
        else if (panel1.Bottom <= panel1.Parent.Height) panel1.Bottom = panel1.Parent.Height;

        Console.WriteLine("panel2.top:" + panel1.Top);

}

Also, the above will work when the panel you are scrolling is "Taller" than the viewport (the form itself). You might need to tweak further when the panel is smaller than the form - so just test a few cases.

You also need to pay attention to the Resize event so your panel has the correct Top property when someone expands the container form.