DiagramConverter Basic Conversion Guide

This guide shows how to convert Visio diagram files between formats using the DiagramConverter class in the Aspose.Diagram.LowCode namespace. DiagramConverter handles Visio-to-Visio format conversions. For Visio-to-PDF conversion, see the PdfConverter Basic Conversion Guide .

Prerequisites

Before using DiagramConverter, ensure you have:

1. Aspose.Diagram for .NET — Install via NuGet:

   dotnet add package Aspose.Diagram
2. License — Apply your metered license before any conversions:

   using Aspose.Diagram;
   
   Metered metered = new Metered();
   metered.SetMeteredKey("publicKey", "privateKey");
3. Input file — A Visio file in any supported input format (see Supported Formats below).

Step 1: Simple File Conversion

The simplest DiagramConverter call takes two string arguments: input path and output path. The output format is determined automatically from the destination file extension.

using Aspose.Diagram.LowCode;

// Convert VSDX to VDX format
DiagramConverter.Process("source.vsdx", "output.vdx");

// Convert legacy VSD to modern VSDX
DiagramConverter.Process("legacy.vsd", "modernized.vsdx");

Step 2: Conversion with Load and Save Options

Use LowCodeLoadOptions and LowCodeSaveOptions when you need explicit control over input and output paths, or when preparing for stream-based processing:

using Aspose.Diagram.LowCode;

var loadOptions = new LowCodeLoadOptions();
loadOptions.InputFile = "source.vsdx";

var saveOptions = new LowCodeSaveOptions();
saveOptions.OutputFile = "output.vdx";

DiagramConverter.Process(loadOptions, saveOptions);

Step 3: Stream-Based Conversion

Use InputStream and OutputStream to convert without writing files to disk. This is the recommended pattern for web applications and batch pipelines:

using System.IO;
using Aspose.Diagram.LowCode;

using var inputStream = File.OpenRead("source.vsdx");
using var outputStream = new MemoryStream();

var loadOptions = new LowCodeLoadOptions();
loadOptions.InputStream = inputStream;

var saveOptions = new LowCodeSaveOptions();
saveOptions.OutputStream = outputStream;

DiagramConverter.Process(loadOptions, saveOptions);

// outputStream now contains the converted diagram bytes
byte[] result = outputStream.ToArray();

Step 4: Batch Conversion

To convert multiple files, call DiagramConverter.Process() in a loop:

using System.IO;
using Aspose.Diagram.LowCode;

string inputDir = "diagrams/input/";
string outputDir = "diagrams/output/";

Directory.CreateDirectory(outputDir);

foreach (string inputFile in Directory.GetFiles(inputDir, "*.vsdx"))
{
    string outputFile = Path.Combine(outputDir, Path.GetFileNameWithoutExtension(inputFile) + ".vdx");
    DiagramConverter.Process(inputFile, outputFile);
}

Supported Formats

Note: The output format is always determined by the destination file extension. For PDF output, use PdfConverter — DiagramConverter converts between Visio formats only.

Troubleshooting

See Also

• API Reference: DiagramConverter
• API Reference: LowCodeLoadOptions
• API Reference: LowCodeSaveOptions
• PdfConverter Basic Conversion Guide — for PDF output
• Developer Guide: DiagramConverter