数据可视化新方式，SankeyDiagramControl类的使用你不能错过！（Part 3）

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自定义Colorizer

要基于自定义算法绘制链接和节点，请创建一个实现ISankeyColorizer接口的类。 然后，将此类的对象分配给Colorizer属性。

以下代码实现了一个 colorizer，该 colorizer将随机颜色应用于节点，并指定用于将渐变填充应用于链接的颜色：

C#

private void Form1_Load(object sender, EventArgs e) {
sankeyDiagramControl1.Colorizer = new MyColorizer {
LinkSourceColor = Color.Red,
LinkTargetColor = Color.Yellow
};

public class MyColorizer : ISankeyColorizer {
public event EventHandler ColorizerChanged;
Random rand = new Random();
Dictionary<string, Color> KeyColorPairs = new Dictionary<string, Color>();
public Color LinkSourceColor { get; set; }
public Color LinkTargetColor { get; set; }
public Color GetLinkSourceColor(SankeyLink link) {
return LinkSourceColor;
}
public Color GetLinkTargetColor(SankeyLink link) {
return LinkTargetColor;
}
public Color GetNodeColor(SankeyNode info) {
if (!KeyColorPairs.TryGetValue((string)info.Tag, out Color nodeColor)) {
nodeColor = GenerateColor();
KeyColorPairs.Add((string)info.Tag, nodeColor);
}
return nodeColor;
}
private Color GenerateColor() {
return Color.FromArgb(rand.Next(256), rand.Next(256), rand.Next(256));
}
}

VB.NET

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
sankeyDiagramControl1.Colorizer = New MyColorizer With {
.LinkSourceColor = Color.Red,
.LinkTargetColor = Color.Yellow
}
End Sub

Public Class MyColorizer
Inherits ISankeyColorizer

Public Event ColorizerChanged As EventHandler
Private rand As Random = New Random()
Private KeyColorPairs As Dictionary(Of String, Color) = New Dictionary(Of String, Color)()
Public Property LinkSourceColor As Color
Public Property LinkTargetColor As Color

Public Function GetLinkSourceColor(ByVal link As SankeyLink) As Color
Return LinkSourceColor
End Function

Public Function GetLinkTargetColor(ByVal link As SankeyLink) As Color
Return LinkTargetColor
End Function

Public Function GetNodeColor(ByVal info As SankeyNode) As Color
Dim nodeColor As Color = Nothing

If Not KeyColorPairs.TryGetValue(CStr(info.Tag), nodeColor) Then
nodeColor = GenerateColor()
KeyColorPairs.Add(CStr(info.Tag), nodeColor)
End If

Return nodeColor
End Function

Private Function GenerateColor() As Color
Return Color.FromArgb(rand.Next(256), rand.Next(256), rand.Next(256))
End Function
End Class

自定义工具提示

当鼠标指针悬停在节点或链接上时，将显示工具提示。 使用 SankeyToolTipOptions.NodeToolTipEnabled、SankeyToolTipOptions.LinkToolTipEnabled和ToolTipController 属性可以禁用/启用工具提示并自定义其外观。 要格式化工具提示文本，请处理CustomizeNodeToolTip和CustomizeLinkToolTip事件，并在事件处理程序中指定CustomizeSankeyToolTipEventArgs.Title和CustomizeSankeyToolTipEventArgs.Content属性。

以下代码格式化了工具提示中使用的文本，e.Node.Tag、e.Link.Source.Tag和e.Link.Target.Tag属性存储在默认工具提示标题中显示的值。 要获取节点和链接权重，请使用e.Node.TotalWeight和e.Link.TotalWeight属性。

C#

private void Form1_Load(object sender, EventArgs e) {
sankeyDiagramControl1.ToolTipOptions.LinkToolTipEnabled = DevExpress.Utils.DefaultBoolean.True;
sankeyDiagramControl1.ToolTipOptions.NodeToolTipEnabled = DevExpress.Utils.DefaultBoolean.True;
sankeyDiagramControl1.ToolTipController = new DevExpress.Utils.ToolTipController { 
ToolTipType = DevExpress.Utils.ToolTipType.Flyout, 
AllowHtmlText = true 
};
sankeyDiagramControl1.CustomizeNodeToolTip += OnCustomizeNodeToolTip;
sankeyDiagramControl1.CustomizeLinkToolTip += OnCustomizeLinkToolTip;
}
private void OnCustomizeNodeToolTip(object sender, CustomizeSankeyNodeToolTipEventArgs e) {
e.Title = $"Country: <u>{e.Node.Tag}</u>";
e.Content = $"{e.Node.TotalWeight:f1}";
}

private void OnCustomizeLinkToolTip(object sender, CustomizeSankeyLinkToolTipEventArgs e) {
e.Title = $"{e.Link.Source.Tag} → {e.Link.Target.Tag}";
e.Content = $"{e.Link.TotalWeight}";
}

VB.NET

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
sankeyDiagramControl1.ToolTipOptions.LinkToolTipEnabled = DevExpress.Utils.DefaultBoolean.[True]
sankeyDiagramControl1.ToolTipOptions.NodeToolTipEnabled = DevExpress.Utils.DefaultBoolean.[True]
sankeyDiagramControl1.ToolTipController = New DevExpress.Utils.ToolTipController With {
.ToolTipType = DevExpress.Utils.ToolTipType.Flyout,
.AllowHtmlText = True
}
sankeyDiagramControl1.CustomizeNodeToolTip += AddressOf OnCustomizeNodeToolTip
sankeyDiagramControl1.CustomizeLinkToolTip += AddressOf OnCustomizeLinkToolTip
End Sub

Private Sub OnCustomizeNodeToolTip(ByVal sender As Object, ByVal e As CustomizeSankeyNodeToolTipEventArgs)
e.Title = $"Country: <u>{e.Node.Tag}</u>"
e.Text = $"{e.Node.TotalWeight:f1}"
End Sub

Private Sub OnCustomizeLinkToolTip(ByVal sender As Object, ByVal e As CustomizeSankeyLinkToolTipEventArgs)
e.Title = $"{e.Link.Source.Tag} → {e.Link.Target.Tag}"
e.Text = $"{e.Link.TotalWeight}";
End Sub

打印和导出

要打印控件，请选择使用以下方法：

• Print
• ShowPrintDialog
• ShowPrintPreview
• ShowRibbonPrintPreview

使用以下方法可以将控件导出为各种格式：

• ExportToDocx
• ExportToHtml
• ExportToImage
• ExportToMht
• ExportToPdf
• ExportToRtf
• ExportToSvg
• ExportToXls

下面的代码将生成的Sankey图图像的宽度设置为文档宽度，并将Sankey图导出为PDF文件：

C#

sankeyDiagramControl1.OptionsPrint.SizeMode = DevExpress.XtraCharts.Printing.PrintSizeMode.Zoom;
sankeyDiagramControl1.ExportToPdf("D://sankey.pdf");

VB.NET

sankeyDiagramControl1.OptionsPrint.SizeMode = DevExpress.XtraCharts.Printing.PrintSizeMode.Zoom
sankeyDiagramControl1.ExportToPdf("D://sankey.pdf")

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