文档介绍：of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of tces in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
                += "鼠标中间点下";
            }
            if ( == )
            {
                += "未按鼠标";
            }
        }
        private void Form1_Load(object sender, EventArgs e)
        {
            //添加消息筛选器以便在向目标传送 Windows 消息时监视这些消息
            (mf);
        }
        //从窗体中移除一个消息筛选器
        private void Frm_Main_FormClosing(object sender, FormClosingEventArgs e)
        {
            //从应用程序的消息泵移除一个消息筛选器
            (mf);
        }
        //方法一，重写WndProc虚方法，与方法二不可同时存在
        protected override void WndProc(ref Message m)
        {
            switch ()//判断系统消息的ID号
            {
                case 513:
                    ("单击了鼠标左键！", "系统信息");
                    = (IntPtr)0;//为了响应消息处理而向 Windows 返回的值
                    break;
                case 516:
                    ("单击了鼠标右键！", "系统信息");
                    = (IntPtr)0;//为了响应消息处理而向 Windows 返回的值
                    break;
                default:
                    (ref m);
                    break;
            }
        }
    }
    //方法二，实现IMessageFilter接口，从而获得Windows消息，与方法一不可同时存在
    public class MessageFilter : IMessageFilter
    {
        public bool PreFilterMessage(ref Message message)
        {
            switch ()//判断系统消息的ID号
            {
of rural drinking water sources, p