c# - 将任何控件与滚动条一起使用时，不会触发 MouseWheel 事件(在 C# Windows 窗体中)

Question

MouseWheel 事件没有触发当我使用带有滚动条的任何控件(ListBox、Panel、TextBox)时。

重现问题:

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();
  }
 }

Answer 1

我遇到了同样的问题，对我有用的是在控件中为事件 MouseEnter 添加一个处理程序，该处理程序在有焦点或没有焦点的情况下触发。

private void chart1_MouseEnter(object sender, EventArgs e)
{
    chart1.Focus();
}

之后我可以毫无问题地获得 mouseWheel 事件。