ArcGIS API for Silverlight 鼠标移入移出地图要素弹出窗口（优化处理）

     在之前博客里的ArcGIS API for Silverlight 弹出框实例中，是通过点击地图要素，弹出框，但是由于没有控制元素个数，只是通过显示隐藏来进行的话，在鼠标移入和移出操作中，会出现鼠标移入的时候，总不能立刻弹出框，而是需要多次才行，用户体验较差，现在通过控制加入一个弹出框，移出时去除刚加入的弹出框，严格控制弹出框个数来实现。

核心代码如下：

//鼠标移入事件 graphic.MouseEnter += new MouseEventHandler(swz_graphic_MouseEnter); graphic.MouseLeave += new MouseEventHandler(swz_graphic_MouseLeave);void swz_graphic_MouseEnter(object sender, MouseEventArgs e){            Point p = e.GetPosition(LayoutRoot);            p.X = p.X - 40;            p.Y = p.Y - 165;            //鼠标左键，显示ToolTip信息            Graphic g = sender as Graphic;            tip_Base.g_TipSW_LeftBottom = new TipSW_LeftBottom(this, p, g.Attributes["SWZMC"].ToString(), g.Attributes["SWZBM"].ToString());} void swz_graphic_MouseLeave(object sender, MouseEventArgs e){            tip_Base.g_TipSW_LeftBottom.closeWindow(this);}public partial class TipSW_LeftBottom : UserControl{        MainPage mp;        string l_name;        string l_swzbm;        public TipSW_LeftBottom()        {            InitializeComponent();        }        public TipSW_LeftBottom(MainPage mp, Point p, string name, string swzbm)        {            InitializeComponent();            this.mp = mp;            this.l_name = name;            this.l_swzbm = swzbm;            //处理标题的间距问题            string tmp = name;            StringBuilder sb = new StringBuilder();            for (int i = 0; i < tmp.Length; i++)            {                sb.Append(tmp[i] + " ");            }            this.title.Content = sb.ToString();            //绑定洪水预报的数据            getDataSoapClient client = new getDataSoapClient();            client.getHSYBInfoCompleted += new EventHandler<getHSYBInfoCompletedEventArgs>(client_getHSYBInfoCompleted);            client.getHSYBInfoAsync(name.Trim());            getXQYJInfoSoapClient client2 = new getXQYJInfoSoapClient();            client2.GetAllSWZCompleted += new EventHandler<GetAllSWZCompletedEventArgs>(client_GetAllSWZCompleted);            client2.GetAllSWZAsync();            this.Margin = new Thickness(p.X, p.Y, 0, 0);            mp.LayoutRoot.Children.Add(this);        }        #region 通用方法，只需要更改Show，在实例化窗体的时候，传入不同的参数即可        private Point _location;        private bool _isShowing;        private Popup _popup;        private Grid _grid;        private Canvas _canvas;        private FrameworkElement _content;        //初始化并显示弹出窗体.公共方法在显示菜单项时调用        public void Show(Point location, string name,string swzbm)        {            this.l_name = name;            this.l_swzbm = swzbm;            if (_isShowing)                throw new InvalidOperationException();            _isShowing = true;            _location = location;            ConstructPopup(this);            _popup.IsOpen = true;            //处理标题的间距问题            string tmp = name;            StringBuilder sb = new StringBuilder();            for (int i = 0; i < tmp.Length; i++)            {                sb.Append(tmp[i] + " ");            }            this.title.Content = sb.ToString();            //绑定洪水预报的数据            getDataSoapClient client = new getDataSoapClient();            client.getHSYBInfoCompleted += new EventHandler<getHSYBInfoCompletedEventArgs>(client_getHSYBInfoCompleted);            client.getHSYBInfoAsync(name.Trim());            //水位站数据            getXQYJInfoSoapClient client2 = new getXQYJInfoSoapClient();            client2.GetAllSWZCompleted += new EventHandler<GetAllSWZCompletedEventArgs>(client_GetAllSWZCompleted);            client2.GetAllSWZAsync();        }        public void Show(Point location)        {            if (_isShowing)                throw new InvalidOperationException();            _isShowing = true;            _location = location;            ConstructPopup(this);            _popup.IsOpen = true;        }        //关闭弹出窗体        public void Close()        {            _isShowing = false;            if (_popup != null)            {                _popup.IsOpen = false;            }        }        //弹出框外面点击则关闭该窗口        protected virtual void OnClickOutside()        {            Close();        }        // 用Grid来布局，初始化弹出窗体        //在Grid里面添加一个Canvas，用来监测菜单项外面的鼠标点击事件        private void ConstructPopup(FrameworkElement _element)        {            if (_popup != null)                return;            _popup = new Popup();            _grid = new Grid();            _popup.Child = _grid;            _canvas = new Canvas();            _canvas.MouseLeftButtonDown += (sender, args) => { OnClickOutside(); };            _canvas.MouseRightButtonDown += (sender, args) => { args.Handled = true; OnClickOutside(); };            _canvas.Background = new SolidColorBrush(Colors.Transparent);            _grid.Children.Add(_canvas);            _content = _element;            _content.HorizontalAlignment = HorizontalAlignment.Left;            _content.VerticalAlignment = VerticalAlignment.Top;            _content.Margin = new Thickness(_location.X, _location.Y, 0, 0);            _grid.Children.Add(_content);            UpdateSize();        }        /// <summary>        /// 更新大小        /// </summary>        private void UpdateSize()        {            _grid.Width = Application.Current.Host.Content.ActualWidth;            _grid.Height = Application.Current.Host.Content.ActualHeight;            if (_canvas != null)            {                _canvas.Width = _grid.Width;                _canvas.Height = _grid.Height;            }        }        #endregion        #region WebService 调用方法及关闭窗体方法        void client_GetAllSWZCompleted(object sender, GetAllSWZCompletedEventArgs e)        {            try            {                ObservableCollection<RiverFall> lists = e.Result;                foreach (RiverFall item in lists)                {                    if (item.SWZBM == l_swzbm)                    {                        this.dt.Content = item.DTNow.ToString("yyyy年M月d日H时");                        this.sw.Content = "水位：" + item.SW.ToString("N2") + "m";                    }                }            }            catch (Exception ex)            {                this.dt.Content = "没有监测到该站点数据";                this.sw.Content = "";            }        }        void client_getHSYBInfoCompleted(object sender, getHSYBInfoCompletedEventArgs e)        {            try            {                IList<洪水预报> ret = e.Result;                if (ret.Count > 0)                {                    foreach (洪水预报 r in ret)                    {                        this.tbhsyb.Text = r.标题.Length > 9 ? r.标题.Substring(0, 7) + "..." : r.标题;                        this.tbhsyb.Foreground = new SolidColorBrush(Colors.Red);                    }                }                else                {                    this.tbhsyb.Text = "暂无预报";                    this.tbhsyb.Foreground = new SolidColorBrush(Colors.Black);                }            }            catch            {            }        }        //用于移除刚加入的弹出框，在主窗体鼠标移出后，调用此方法        public void closeWindow(MainPage mp)        {             mp.LayoutRoot.Children.RemoveAt(mp.LayoutRoot.Children.Count - 1);        }        #endregion    }

这里代码中仍然保留了原先的点击弹出框的Show方法，可以根据需要调用Show方法或直接实例化带参数的构造函数都可以。