WPF自动浏览

迷南。 2022-03-28 11:14 163阅读 0赞

因为图片轮巡功能中需要实现一个图片自动浏览，循环播放，就是类似与小说中自动阅读效果。如图：

![图片自动浏览][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0NjI5OA_size_16_color_FFFFFF_t_70]

第一步，在主页面加一个自动浏览的按钮，就是一个下拉框，实现自动浏览的开启和关闭。加个选择点击事件：

/// <summary>
            /// 自动浏览
            /// </summary>
            /// <param name="sender"></param>
            /// <param name="e"></param>
            private void AutoGlaceOver_SelectionChanged(object sender, SelectionChangedEventArgs e)
            {
                if (picTour.AutoGlaceOver.SelectionBoxItem == null)
                {
                    return;
                }
                if ("开启".Equals(picTour.AutoGlaceOver.SelectionBoxItem.ToString()))
                {
    
                    picTour.PictureTourControl01.timeNotice.Start();
                    picTour.PictureTourControl01.timerWoke();
                }
                else
                {
                    picTour.PictureTourControl01.timeNotice.Stop();
                }
            }

第二步，在滚动条加个方法，来控制滚动条的滚动效果，记住，一定要另起一个线程，不然滚动就会有卡顿，停止等现象。

//定时器
            public  Timer timeNotice = new Timer();
            //滚动条
            private  ScrollViewer scroll;
            /// <summary>
            /// 定时器设置
            /// </summary>
            public void timerWoke()
            {
                timeNotice.Elapsed += new ElapsedEventHandler(ScrollRolling);
                timeNotice.Interval = 500;
            }
            /// <summary>
            /// 滚动条
            /// </summary>
            /// <param name="sender"></param>
            /// <param name="e"></param>
            public  void ScrollRolling(object sender, ElapsedEventArgs e)
            {
                double oldVerticalOffset=this.scroll.VerticalOffset;
                this.scroll.Dispatcher.Invoke(
                    new Action(
                          delegate
                          {
                              if (this.scroll.VerticalOffset<= (oldVerticalOffset))
                              {
                                  scroll.ScrollToVerticalOffset(this.scroll.VerticalOffset + 10);
                                  bool isFoot = IsVerticalScrollBarAtButtom(scroll);
                                  if (isFoot)
                                  {
                                      scroll.ScrollToTop();
                                  }
                              }
                              else
                              {
                                  scroll.ScrollToVerticalOffset(this.scroll.VerticalOffset);
                                  bool isFoot = IsVerticalScrollBarAtButtom(scroll);
                                  if (isFoot)
                                  {
                                  //当滚动条到达底部过后，返回顶部
                                      scroll.ScrollToTop();
                                  }
                              }
                          }
                        )
                    );}

第三步，判断滚动条是否到达底部,从而实现循环滚动。

/// <summary>
            /// 判断滚动条是否到达底部
            /// </summary>
            /// <param name="s"></param>
            /// <returns></returns>
            public bool IsVerticalScrollBarAtButtom(ScrollViewer s)
            {
                bool isAtButtom = false;
                double dVer = s.VerticalOffset;
                double dViewport = s.ViewportHeight;
                double dExtent = s.ExtentHeight;
                if (dVer != 0)
                {
                    if (dVer + dViewport == dExtent)
                    {
                        isAtButtom = true;
                    }
                    else
                    {
                        isAtButtom = false;
                    }
                }
                else
                {
                    isAtButtom = false;
                }
                if (s.VerticalScrollBarVisibility == ScrollBarVisibility.Disabled
                    || s.VerticalScrollBarVisibility == ScrollBarVisibility.Hidden)
                {
                    isAtButtom = true;
                }
                return isAtButtom;
            }

最后一步，关注我。

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80NDQ0NjI5OA_size_16_color_FFFFFF_t_70]: /images/20220328/fcd3448f5eb3498da784449c591d67c5.png