FlowChart.NET是一個通用的流程圖控件，提供了用于創建或編輯圖表的直觀的用戶交互模型。本教程展示在FlowChart.NET如何創建自定義節點類型。

1、定義一個自定義節點類

DiagramNode定義自定義節點類（本教程中使用的名稱IconNode ）。

C#

public class IconNode : DiagramNode
{
}

Visual Basic

Public Class IconNode
    Inherits DiagramNode

End Class

2、定義一個靜態構造函數

頂一個靜態構造函數來初始化類的靜態成員。

C#

static IconNode()
{
    defaultIcon = new Bitmap(48, 48);

    Graphics graphics = Graphics.FromImage(defaultIcon);
    Font font = new Font("Arial", 48, FontStyle.Bold, GraphicsUnit.Pixel);

    graphics.FillRectangle(Brushes.Transparent, 0, 0, 48, 48);
    graphics.DrawString("?", font, Brushes.Black, 0, 0);

    font.Dispose();
    graphics.Dispose();
} 

Visual Basic

Shared Sub New()

    defaultIcon = New Bitmap(48, 48)

    Dim graphics As Graphics = graphics.FromImage(defaultIcon)
    Dim font As Font = New Font("Arial", 48, FontStyle.Bold, GraphicsUnit.Pixel)

    graphics.FillRectangle(Brushes.Transparent, 0, 0, 48, 48)
    graphics.DrawString("?", font, Brushes.Black, 0, 0)

    font.Dispose()
    graphics.Dispose()

End Sub

3、定義一個公共的構造函數

定義構造函數來初始化實例成員。

C#

public IconNode(Diagram diagram) : base(diagram)
{
    icon = defaultIcon;
    label = "Label";

    format = new StringFormat();
    format.Alignment = StringAlignment.Center;
    format.LineAlignment = StringAlignment.Center;

    Bounds = new RectangleF(Bounds.Location, CalculateSize());
}

Visual Basic

Sub New(ByVal diagram As Diagram)

    MyBase.New(diagram)

    fIcon = defaultIcon
    fLabel = "Label"

    format = New StringFormat
    format.Alignment = StringAlignment.Center
    format.LineAlignment = StringAlignment.Center

    Bounds = New RectangleF(Bounds.Location, CalculateSize())

End Sub