15.Visifire圖表控件的使用二(DataPoint點擊事件和Legend文字標註欄的點擊事件)

        圖表應用於表現數據量，進行直觀的對比，可是在某一些領域中若是數據之間大小差別過大，那麼會出現某一些數據由於太小，而沒法讓用戶看見的狀況。例如在統 計一組用戶電腦的網絡發包量的時候，有一些用戶開啓電腦幾十個小時，有一些用戶開啓電腦幾秒鐘。很明顯用戶開機幾十個小時的發包量巨大，而開機幾秒鐘的發 包量極小，若是放在一個Visifire的圖標中組成一個統計列的時候，發包量小的電腦幾乎看不見了。這種狀況下，咱們就能夠經過點擊文字標註欄的 Legend文字來肯定某一個在圖表上看不見的用戶電腦的發包量。

        首先咱們設置一個實體類，該類包含（ComputerName，NetWorkNum）兩個屬性，分別代碼電腦名和電腦網絡發包量：

 

/// <summary>
  /// 電腦信息
  /// </summary>
  public class  ComputerInfomation
  {
      string _ComputerName;
      string _NetWorkNum;
      /// <summary>
      /// 電腦名稱
      /// </summary>
      public string ComputerName
      {
          get { return _ComputerName; }
          set { _ComputerName = value; }
      }
      /// <summary>
      /// 網絡發送包
      /// </summary>
      public string NetWorkNum
      {
          get { return _NetWorkNum; }
          set { _NetWorkNum = value; }
      }
  }

        再實例化該類造成多個實體類對象集合，MainPage.xaml.cs的構造函數中敲入代碼以下：

 

ComputerList = new List<ComputerInfomation>()
          {
          new ComputerInfomation(){ComputerName="張三的電腦", NetWorkNum="32143242223"},
          new ComputerInfomation(){ComputerName="李四的電腦", NetWorkNum="23432423"},
          new ComputerInfomation(){ComputerName="王五的電腦", NetWorkNum="12342342344"},
          new ComputerInfomation(){ComputerName="劉六的電腦", NetWorkNum="562342"},
          new ComputerInfomation(){ComputerName="林七的電腦", NetWorkNum="55353453445"},
          new ComputerInfomation(){ComputerName="馬林的電腦", NetWorkNum="2454555543"}
          };
          BindChart(ComputerList);

        如今用戶電腦數據已經準備好了，咱們開始製做一個函數，此函數建立一個圖表而且設置相應的Legend文字標註欄的事件綁定：

 

List<ComputerInfomation> ComputerList = new List<ComputerInfomation>();
/// <summary>
/// 綁定一個圖標
/// </summary>
/// <param name="computerList">用戶電腦類實體集合</param>
public void BindChart( List<ComputerInfomation> computerList)
{
Chart chart = new Chart();
chart.Width = 400;
chart.Height = 550;
chart.Name = "Chart";
chart.SetValue(Canvas.LeftProperty, 30.0);
chart.SetValue(Canvas.TopProperty, 30.0);
chart.Theme = "Theme1";//設置皮膚
chart.BorderBrush = new SolidColorBrush(Colors.Gray);
chart.AnimatedUpdate = true;
chart.CornerRadius = new CornerRadius(7);
chart.ShadowEnabled = true;
chart.Padding = new Thickness(4, 4, 4, 10);

#region 設置Title
Title title = new Title();
title.Text = "電腦網絡發包統計";
chart.Titles.Add(title);
#endregion

#region 設置AxesX
Axis xAxis = new Axis();
xAxis.Title = "用戶電腦";
chart.AxesX.Add(xAxis);
#endregion

#region 設置AxesY
Axis yAxis = new Axis();
yAxis.Title = "用戶網卡發送包";
yAxis.Prefix = "發送：";
yAxis.Suffix = "包";
chart.AxesY.Add(yAxis);
#endregion

#region 設置PlotArea
PlotArea plot = new PlotArea();
plot.ShadowEnabled = false;
chart.PlotArea = plot;
#endregion

#region 設置Legends
Legend legend = new Legend();
//Legend文字標註欄綁定一個事件Legend_MouseLeftButtonDown
legend.MouseLeftButtonDown += new EventHandler<LegendMouseButtonEventArgs>(Legend_MouseLeftButtonDown);
chart.Legends.Add(legend);
#endregion
#region
Visifire.Charts.ToolTip tip = new Visifire.Charts.ToolTip();
tip.VerticalAlignment = VerticalAlignment.Bottom;
chart.ToolTips.Add(tip);
#endregion
#region 建立數據序列和數據點
foreach (ComputerInfomation cominfo in computerList)
{
DataSeries dseries = new DataSeries();
//設置一個數據序列的LengendText值爲ComputerName
dseries.LegendText = cominfo.ComputerName;
//設置圖表的類型爲RenderAs.StackedColumn
dseries.RenderAs = RenderAs.StackedColumn;
//設置一個數據點
DataPoint dpointUpload = new DataPoint();
//數據點的Y座標值
dpointUpload.YValue =double.Parse(cominfo.NetWorkNum);
//數據點的Tag值也爲電腦名稱，用於數據點被點擊後對比判斷當前點擊的點
dpointUpload.Tag = cominfo.ComputerName;
//設置數據點被點擊以後觸發事件Dpoint_MouseLeftButtonDown
dpointUpload.MouseLeftButtonDown += new MouseButtonEventHandler(Dpoint_MouseLeftButtonDown);
dseries.DataPoints.Add(dpointUpload);
chart.Series.Add(dseries);
}
#endregion
#region 設置遮罩，將Visifire的LOGO遮擋住。
StackPanel sp = new StackPanel();
sp.Width = 145;
sp.Height = 15;
sp.Margin = new Thickness(0, 3, 3, 0);
sp.VerticalAlignment = VerticalAlignment.Top;
sp.HorizontalAlignment = HorizontalAlignment.Right;
sp.Background = new SolidColorBrush(Colors.White);
#endregion
LayoutRoot.Children.Add(chart);
LayoutRoot.Children.Add(sp);
}

        關鍵在於Lengend事件的設置，那麼下面咱們貼出Lengend被點擊事件和DataPoint被點擊事件的處理函數：

 

/// <summary>
  /// DataPoint被點擊執行事件
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  void Dpoint_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
  {
      //接收到當前被點擊的LengendText的值
      DataPoint dpoint = sender as DataPoint;
      string str = dpoint.Tag.ToString();
      foreach (ComputerInfomation cominfo in ComputerList)
      {
          if (str == cominfo.ComputerName)
          {
              MessageBox.Show(cominfo.ComputerName + "網絡發送：" + cominfo.NetWorkNum + "數據包");
          }
      }
  }
  /// <summary>
  /// Legend文字被點擊執行的事件
  /// </summary>
  /// <param name="sender"></param>
  /// <param name="e"></param>
  private void Legend_MouseLeftButtonDown(object sender, LegendMouseButtonEventArgs e)
  {
      //接收到當前被點擊的LengendText的值
      string str = e.DataSeries.LegendText.ToString();
      foreach (ComputerInfomation cominfo in ComputerList)
      {
          if (str == cominfo.ComputerName)
          {
              MessageBox.Show(cominfo.ComputerName + "網絡發送：" + cominfo.NetWorkNum + "數據包");
          }
      }
  }

        如此就解決了本文開頭所述的圖標繪製的問題。本實例採用VS2010+Silverlight 4.0編寫，點擊 SLTOVisiFire.rar 下載源碼。運行效果以下：