求基于C#程序化绘制BPMN 2.0等图表的解决方案，支持Excel输入

Hey there! Let's break down practical, actionable solutions for your C# diagramming needs—programmatically drawing BPMN 2.0, general flowcharts, and use case diagrams, with Excel as your input source. Here's what I recommend:

These libraries handle heavy lifting for standard diagram types, with built-in support or easy extensibility:

• Syncfusion Diagram Control
  Fully supports BPMN 2.0 standards, with pre-built shapes for tasks, gateways, events, and more. You can programmatically create, arrange, and style diagrams, then export to PNG, PDF, or SVG. Pair it with Excel parsing libraries to map spreadsheet data directly to diagram elements.
• Telerik UI for WinForms/WPF Diagram
  Offers robust BPMN 2.0 and flowchart support, with both visual design tools and a flexible API for code-driven creation. Ideal for desktop applications—you can loop through Excel data to spawn nodes, define connections, and apply styling in just a few lines.
• Open-Source Option: Netron Library
  A lightweight, open-source library great for custom scenarios. While it doesn’t have out-of-the-box BPMN support, you can define custom shape templates for BPMN 2.0 elements, then populate them using data pulled from Excel. Perfect if you need full control over diagram structure.

Use case diagrams require specific shapes (actors, use cases, associations), and these tools deliver:

• The Syncfusion and Telerik libraries mentioned above include dedicated use case diagram shapes—just map Excel data (actor names, use case titles, association types) to their respective API objects.
• GraphViz.NET (Open-Source)
  Leverage GraphViz’s DOT language to describe use case diagrams. Convert your Excel data into DOT syntax (e.g., actor "End User", usecase "Submit Request", End User -> Submit Request), then use the C# wrapper to render the diagram as an image or PDF.

To make parsing smooth, structure your Excel template intentionally:

• Split data into separate worksheets: one for nodes (ID, type, name, optional coordinates) and one for connections (start node ID, end node ID, relationship type).
• Use reliable Excel parsing libraries:
  • EPPlus (for .NET Core/.NET 5+): Clean, modern API for reading/writing Excel files.
  • NPOI (supports legacy .NET frameworks): Great if you’re working with older project setups.

Here’s a quick code snippet to illustrate reading node data:

using var package = new ExcelPackage(new FileInfo("diagram_input.xlsx"));
var nodeSheet = package.Workbook.Worksheets["Nodes"];

// Skip header row, loop through data rows
for (int row = 2; row <= nodeSheet.Dimension.End.Row; row++)
{
    var nodeId = nodeSheet.Cells[row, 1].Text;
    var nodeType = nodeSheet.Cells[row, 2].Text; // e.g., "BPMN_Task", "Actor", "UseCase"
    var nodeName = nodeSheet.Cells[row, 3].Text;
    
    // Map this data to your diagram library's node creation logic
}

• If you need flexibility, you can even add a step to convert Excel data to JSON/CSV first, but direct Excel parsing works perfectly for most cases.

1. Design your Excel template with clear, consistent data fields for nodes and connections.
2. Parse Excel data into a C# object model (e.g., DiagramNode and DiagramConnection classes).
3. Use your chosen diagram library’s API to generate elements from the object model—set positions, styles, and connections.
4. Export the finished diagram to your desired format (PDF, SVG, PNG) or display it in a desktop UI.

内容的提问来源于stack exchange，提问作者user2537735