异步创建读取文件：批量生成Word文档性能优化技术问询

Let's cut straight to it: your current approach using Word Interop is the main culprit here. Interop is built for interactive desktop use, not bulk automation—each document creation spins up heavy COM resources, and the repeated disk I/O just piles on unnecessary overhead. Here's how to fix this drastically:

1. Ditch Word Interop for OpenXML SDK (The Biggest Performance Boost) #

The OpenXML SDK lets you create Word documents entirely in memory, no Word application required. It's fast, lightweight, and perfect for bulk operations. Here's a rewritten version of your method:

using DocumentFormat.OpenXml;
using DocumentFormat.OpenXml.Packaging;
using DocumentFormat.OpenXml.Wordprocessing;
using System.IO;

public async Task<byte[]> ConvertToWordDocument(string letterBody, int index)
{
    // Generate the document entirely in memory—no temp files!
    using var memoryStream = new MemoryStream();
    using var wordDocument = WordprocessingDocument.Create(memoryStream, WordprocessingDocumentType.Document);

    // Set up the basic document structure
    var mainPart = wordDocument.AddMainDocumentPart();
    mainPart.Document = new Document();
    var body = mainPart.Document.AppendChild(new Body());

    // Insert your letter body as a paragraph
    var paragraph = body.AppendChild(new Paragraph());
    var run = paragraph.AppendChild(new Run());
    run.AppendChild(new Text(letterBody));

    // Save and return the byte array directly
    mainPart.Document.Save();
    return memoryStream.ToArray();
}

With this change, generating 50 documents should take seconds, not 40 seconds. No more waiting for Word to launch, create documents, or write to disk—everything happens in memory.

2. Cut Out Disk I/O (Even If You Stick With Interop) #

If you can't switch to OpenXML immediately, eliminate the temp file step and clean up your Interop usage:

• Reuse a single Word application instance instead of implicitly spawning new ones.
• Create an empty template document once, then duplicate it for each letter instead of starting from scratch.
• Properly release all COM objects (your current code misses releasing Application and Content objects, which can cause memory leaks and slowdowns).

Warning: Interop isn't thread-safe, so wrapping it in Task.Run might cause unexpected crashes or slowdowns—stick to single-threaded execution if you keep using it.

3. Batch & Parallelize Smartly #

With OpenXML, you can safely parallelize document generation since it's thread-safe. For 50 documents, use Parallel.ForEach to generate multiple at once (test with 2-4 threads first to avoid overwhelming your system):

var letterBodies = GetYourLetterBodies(); // Your list of 50 letter contents
var documentBytesList = new List<byte[]>();

Parallel.ForEach(letterBodies, (body, state, index) =>
{
    var bytes = ConvertToWordDocument(body, (int)index).Result;
    documentBytesList.Add(bytes);
});

Bonus: Use a Wrapper Library for Complex Formatting #

If you need styles, tables, or other advanced formatting, consider using an open-source wrapper like DocX (which simplifies OpenXML code). It lets you write cleaner code while still getting the performance benefits of OpenXML.

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