解决cefsharp在winform中不显示tooltipText问题（网页元素的title提示）

1.监听网页属性改变事件

webView.PropertyChanged += webView_PropertyChanged;

2.拖一个ToolTip控件到窗体

3.在webView_PropertyChanged这个事件处理函数中，获取TooltipText并显示出来

  //隐藏toolTip
                if (this.IsHandleCreated)
                {
                    this.BeginInvoke(new MethodInvoker(() =>
                    {
                        if (this.IsHandleCreated && !this.IsDisposed)
                        {
                            if (this.toolTip1.Active)
                            {
                                this.toolTip1.Hide(this);
                            }
                        }
                    }));
                }

                if (e.PropertyName == "TooltipText") //tooltipText改变事件
                {
                    string tooltipText = this.webView.TooltipText;
                    Point elementPos = new Point(Cursor.Position.X - this.Location.X, Cursor.Position.Y - this.Location.Y);
                    if (!String.IsNullOrEmpty(tooltipText))
                    {
                        this.Invoke(new MethodInvoker(() =>
                        {
                            System.Windows.Forms.Timer timer = new System.Windows.Forms.Timer();
                            timer.Interval = ;
                            timer.Tick += (timer_sender, timer_e) =>
                            {
                                Point nowPos = new Point(Cursor.Position.X - this.Location.X, Cursor.Position.Y - this.Location.Y);
                                //if ((nowPos.X <= elementPos.X + 20 && nowPos.X >= elementPos.X - 20) && (nowPos.Y <= elementPos.Y + 20 && nowPos.Y >= elementPos.Y - 20)) //鼠标停留了500ms(范围限定在一定范围)
                                if (this.webView.TooltipText == tooltipText) //600毫秒后，tooltipText没变
                                {
                                    this.toolTip1.Show(tooltipText, this, nowPos.X + , nowPos.Y + );
                                }
                                (timer_sender as System.Windows.Forms.Timer).Stop();
                                (timer_sender as System.Windows.Forms.Timer).Dispose();
                            };
                            timer.Start();

                        }));
                    }
                }