【提问】为何自定义控件中重载的事件无法响应，请看代码

    public partial class PicListEx : UserControl    {        private Size size = new Size(100, 100);        private Thread LoadPictureThread = null;        public PicListEx()        {            InitializeComponent();            lViewPic.View = View.LargeIcon;        }        /// <summary>        /// 加载图片        /// </summary>        /// <param name="filePaths">包含图片路径的数组</param>        public void loadPicFile(List<string> filePaths)        {            if (LoadPictureThread == null || !LoadPictureThread.IsAlive)            {                LoadPictureThread = new Thread(new ParameterizedThreadStart(LoadPictureFunc));                LoadPictureThread.IsBackground = true;                LoadPictureThread.Start(filePaths);            }            else            {                return;            }        }        private void LoadPictureFunc(object obj)        {            List<string> filePaths = null;            if (obj is List<string>)            {                filePaths = obj as List<string>;            }            else            {                return;            }            try            {                Invoke(new MethodInvoker(new Action(delegate()                {                    lViewPic.Items.Clear();                    lViewPic.BeginUpdate();                })));                ImageList Ilist = new ImageList();//与ListView关联的大图标列表                Ilist.ImageSize = size;//设置大小                Invoke(new MethodInvoker(new Action(delegate()                {                    lViewPic.LargeImageList = Ilist;  //关联                })));                foreach (string filePath in filePaths)                {                    if (File.Exists(filePath))                    {                        string fileName = Path.GetFileNameWithoutExtension(filePath);                        Image img = ResizeImage(filePath);                        Invoke(new MethodInvoker(new Action(delegate()                        {                            Ilist.Images.Add(filePath, img);                        })));                        ListViewItem lvitem = new ListViewItem(fileName);                        lvitem.Tag = filePath;                        lvitem.ImageKey = filePath;                        Invoke(new MethodInvoker(new Action(delegate()                        {                            lViewPic.Items.Add(lvitem);                        })));                        img.Dispose();                    }                }                Invoke(new MethodInvoker(new Action(delegate()                {                    lViewPic.EndUpdate();                    lViewPic.Refresh();                })));            }            catch (Exception ex)            {                MessageBox.Show(this, ex.Message);            }            finally            {                Invoke(new MethodInvoker(new Action(delegate()                    {                    })));            }        }         private void lViewPic_Click(object sender, EventArgs e)        {            MessageBox.Show("自定义控件内_单击事件.");//**能够响应        }        private void lViewPic_MouseClick(object sender, MouseEventArgs e)        {            MessageBox.Show("自定义控件内_鼠标点击事件.");//**能够响应        }        protected override void OnClick(EventArgs e)        {            MessageBox.Show("重载的自定义控件单击事件.");//**无法响应            base.OnClick(e);        }        protected override void OnMouseEnter(EventArgs e)        {            MessageBox.Show("重载的自定义控件鼠标进入控件事件.");//**无法响应            base.OnMouseEnter(e);        }    }

    public partial class FormMain : Form    {        public FormMain()        {            InitializeComponent();            picListExLeft.Click += picListExLeft_Click;        }        string filePath = "";        private void tsBtn_OpenForld_Click(object sender, EventArgs e)        {            string folderPath = "";            FolderBrowserDialog folderDlg = new FolderBrowserDialog();            if (folderDlg.ShowDialog() == DialogResult.OK)            {                folderPath = folderDlg.SelectedPath;            }            List<string> listfile = new List<string>();            if (folderPath != "" && Directory.Exists(folderPath))            {                DirectoryInfo dirInfo = new DirectoryInfo(folderPath);                foreach (FileInfo fileinfo in dirInfo.GetFiles())                {                    if (fileinfo.Extension.ToUpper() == ".JPG")                        listfile.Add(fileinfo.FullName);                }            }            folderDlg.Dispose();            folderDlg = null;            if (listfile.Count > 0)            {                picListExLeft.loadPicFile(listfile);            }        }        private void tsBtn_OpenPic_Click(object sender, EventArgs e)        {            OpenFileDialog openFd = new OpenFileDialog();            if (openFd.ShowDialog() == DialogResult.OK)            {                filePath = openFd.FileName;            }            openFd.Dispose();            openFd = null;            if (filePath != "")            {                List<string> listTem = new List<string>();                listTem.Add(filePath);                picListExLeft.loadPicFile(listTem);            }        }        private void picListExLeft_Click(object sender, EventArgs e)        {            ListViewItem item = picListExLeft.GetListViewSelectedItem;            if (item != null && (item.Tag as string).Trim() != "")            {                MessageBox.Show((item.Tag as string).Trim());            }        }        private void picListExLeft_MouseClick(object sender, MouseEventArgs e)        {            MessageBox.Show("鼠标单击");////**无法响应        }        private void picListExLeft_Load(object sender, EventArgs e)        {            MessageBox.Show("LOAD");        }        private void picListExLeft_MouseDoubleClick(object sender, MouseEventArgs e)        {            MessageBox.Show("双击");//**无法响应        }        private void picListExLeft_MouseEnter(object sender, EventArgs e)        {            MessageBox.Show("鼠标进入");//**无法响应        }    }