创建标签时，按如下方式设置DoubleClick处理程序：

// ...
Label labeltest= new Label();
labeltest.DoubleClick += Label_DoubleClick;

在行程常式中，您可以将暂时的TextBox加入至表单，将它放在原始标签上，等到使用者按下Enter或Escape，然后变更或不变更原始文字并移除文字方块，如下所示：

protected void Label_DoubleClick(object? sender, EventArgs e)
{
    if (sender is Label label)
    {
        var box = new TextBox();
        box.Name = "TextField";
        box.Text = label.Text;
        box.TextAlign = HorizontalAlignment.Center;
        box.AutoSize = false;
        box.Dock = DockStyle.None;
        box.Size = label.Size;
        box.Location = this.PointToClient(label.Parent.PointToScreen(label.Location));
        box.BackColor = BackColor;
        box.PreviewKeyDown += (a, b) => {
            if (b.KeyCode == Keys.Escape)
            {
                box.Parent.Controls.Remove(box);
            }
            else if (b.KeyCode == Keys.Enter)
            {
                label.Text = box.Text;
                box.Parent.Controls.Remove(box);
            }
        };
        box.LostFocus += (a, b) => { box.Parent?.Controls.Remove(box); };

        Controls.Add(box);
        Controls.SetChildIndex(box, 0);
        box.SelectAll();
        box.Focus();
    }
}