能否用C#访问Adobe Lightroom目录并编辑关键词？求实现方案

Great questions—let’s break these down with practical, supported approaches since automating Lightroom workflows with C# is a common use case for developers.

1. Can I edit Lightroom keywords using C#? #

Absolutely! While Adobe’s official Lightroom SDK is Lua-based, there are reliable ways to interact with Lightroom’s keyword system from C#:

Option 1: Use Lightroom’s COM Interface #

Most Lightroom Classic versions expose a COM interface that C# can access via interop. This lets you connect directly to a running Lightroom instance, access photos, and modify their keywords. Here’s a quick working example:

using System;
using System.Runtime.InteropServices;

class LrKeywordEditor
{
    static void Main()
    {
        try
        {
            // Connect to a running Lightroom instance
            dynamic lrApp = Activator.CreateInstance(Type.GetTypeFromProgID("Lightroom.Application"));
            var selectedPhotos = lrApp.SelectedPhotos;

            foreach (var photo in selectedPhotos)
            {
                // Add a new keyword (you can also remove or modify existing ones)
                photo.Keywords.Add("Automated-C#");
                Console.WriteLine($"Updated keywords for: {photo.Name}");
            }
        }
        catch (Exception ex)
        {
            Console.WriteLine($"Oops, hit an issue: {ex.Message}");
        }
    }
}

Option 2: C# + Lightroom Lua Scripts #

For newer Lightroom versions, using the official SDK (via Lua) is more stable. Write a Lua script that handles keyword edits, then trigger it from C# via the command line:

1. Create a Lua script (add_keyword.lua) that targets specific photos and updates keywords.
2. Call it from C#:

var process = new System.Diagnostics.Process();
process.StartInfo.FileName = @"C:\Program Files\Adobe\Adobe Lightroom Classic\lightroom.exe";
process.StartInfo.Arguments = "-r \"C:\\path\\to\\add_keyword.lua\"";
process.Start();

2. Can I access the Lightroom catalog externally to extract, process, and write back photos + keywords? #

Yes, but direct manipulation of the Lightroom SQLite catalog is strongly discouraged—Adobe doesn’t support it, catalog structures change between versions, and the catalog is locked while Lightroom runs. Instead, use these supported workflows:

Recommended: C# for Processing + Lightroom API for Catalog Sync #

1. Fetch photo paths: Use the COM interface or Lua SDK to get paths to the photos you want to process (avoid reading the SQLite DB directly).
2. Process images in C#: Use libraries like ImageSharp, SkiaSharp, or System.Drawing to edit your photos.
3. Update metadata & sync to catalog:
   • Use a tool like ExifTool to write keywords directly to the image’s metadata (C# can call ExifTool via process execution).
   • Tell Lightroom to sync the photo’s metadata to update the catalog:

     dynamic lrApp = Activator.CreateInstance(Type.GetTypeFromProgID("Lightroom.Application"));
     var targetPhoto = lrApp.GetPhotoByPath(@"C:\path\to\processed\photo.jpg");
     targetPhoto.SyncMetadata(); // Forces Lightroom to pull updated keywords from the image
     

Alternative: Lightroom Cloud API (for Lightroom CC) #

If you’re working with Lightroom CC (not Classic), Adobe offers a REST API that you can call from C#. This lets you access cloud-stored photos, modify metadata, and sync changes back without dealing with local catalogs.

Key Tips & Common Practices #

• Skip direct SQLite edits: I’ve seen numerous cases where this corrupts catalogs, especially after Lightroom updates. Stick to supported APIs.
• Test with your Lightroom version: COM interfaces can change between releases, so always validate your code against the exact version your users run.
• Batch efficiently: For large photo sets, use the SDK’s batch processing capabilities in Lua, then trigger it from C#—it’s far more efficient than looping through photos via COM.

内容的提问来源于stack exchange，提问作者Schlodi