Silverlight LineDataPoint在MouseOver上增加大小

Question

我在資源字典中爲工具包提供的LineDataPoint使用了自定義樣式。

我希望數據點在鼠標懸停事件上增加大小，並在鼠標離開後恢復爲其原始大小。實現這個最好的方法是什麼？

Answer 1

我還沒有找到一個更好的解決方案，然後使用擴展類必需的功能：

public class ExtendedLineSeries : LineSeries 
{ 
    //I assume that all points have the same size 
    private double _originalDataPointWidth; 
    private double _originalDataPointHeight; 

    protected override DataPoint CreateDataPoint() 
    { 
     var dp = base.CreateDataPoint(); 

     if (this.IncreaseDataPointSizeTo != null) 
     { 
      dp.MouseEnter += new MouseEventHandler(OnDataPointMouseEnter); 
      dp.MouseLeave += new MouseEventHandler(OnDataPointMouseLeave); 
     } 

     return dp; 
    } 
    /// <summary> 
    /// The width and height to which the point is increased in size 
    /// </summary> 
    public double? IncreaseDataPointSizeTo { get; set; } 

    void OnDataPointMouseLeave(object sender, MouseEventArgs e) 
    { 
     var dp = sender as DataPoint; 
     if (dp != null) 
     { 
      //return to the original size 
      dp.Width = _originalDataPointWidth; 
      dp.Height = _originalDataPointHeight; 
      dp.UpdateLayout(); 
      base.UpdateDataPoint(dp); 
     } 
    } 

    void OnDataPointMouseEnter(object sender, MouseEventArgs e) 
    { 
     var dp = sender as DataPoint; 
     if (dp != null) 
     { 
      //remember the original size and enlarge the data point 
      _originalDataPointWidth = dp.ActualWidth; 
      _originalDataPointHeight = dp.ActualHeight; 
      dp.Width = dp.Height = IncreaseDataPointSizeTo.Value; 
      dp.UpdateLayout(); 
      base.UpdateDataPoint(dp); 
     } 
    } 
} 

這個類可以到處在您使用普通LineSeries類中使用。它具有附加屬性IncreaseDataPointSizeTo，其中包含懸停數據點的寬度和高度的最終大小。的XAML代碼

實施例：

<charting:Chart> 
    <charting:Chart.Series> 
     <ext:ExtendedLineSeries IsSelectionEnabled="True" 
           IncreaseDataPointSizeTo="16" ...