MouseWheel event doesn't fire when I' am using any control (ListBox, Panel, TextBox) with scrollbars.
To reproduce problem:
public class Form1 : Form
{
private readonly Button button1;
private readonly TextBox textBox1;
private void button1_MouseWheel(object sender, MouseEventArgs e)
{
ToString(); // doesn't fire when uncomment lines below
}
public Form1()
{
button1 = new Button();
textBox1 = new TextBox();
SuspendLayout();
button1.Location = new System.Drawing.Point(80, 105);
button1.Size = new System.Drawing.Size(75, 23);
button1.MouseWheel += button1_MouseWheel;
button1.Click += button1_Click;
textBox1.Location = new System.Drawing.Point(338, 105);
//textBox1.Multiline = true; // uncomment this
//textBox1.ScrollBars = ScrollBars.Vertical; // uncomment this
textBox1.Size = new System.Drawing.Size(100, 92);
ClientSize = new System.Drawing.Size(604, 257);
Controls.Add(textBox1);
Controls.Add(button1);
ResumeLayout(false);
PerformLayout();
}
// Clicking the button sets Focus, but even I do it explicit Focus() or Select()
// still doesn't work
private void button1_Click(object sender, System.EventArgs e)
{
button1.Focus();
button1.Select();
}
}
I was having the same problem, and what worked for me was to add a handler for the event MouseEnter in the control, that one is triggered with or without focus.
private void chart1_MouseEnter(object sender, EventArgs e)
{
chart1.Focus();
}
After that I could get the mouseWheel events with no problems.