Implement custom logger c# in GroupDocs.Redaction for .NET

Managing document redactions efficiently is critical, especially when handling sensitive information. In this guide you’ll learn how to implement a custom logger c# with GroupDocs.Redaction for .NET, giving you full control over logging, error handling, and audit trails.

Quick Answers

  • What does a custom logger c# do? It captures errors, warnings, and informational messages during redaction.
  • Which library provides the ILogger interface? GroupDocs.Redaction for .NET.
  • Can I save the redacted document without rasterization? Yes – use redactor.Save(..., new Options.RasterizationOptions { Enabled = false }).
  • Do I need a license for production use? A full license is required for production; a trial is available for evaluation.
  • Is this approach compatible with .NET Core / .NET 6+? Absolutely – the same API works across .NET Framework and .NET Core/5/6.

What is a custom logger c#?

A custom logger c# is a class that implements the ILogger interface supplied by GroupDocs.Redaction. It lets you route log messages wherever you need—console, file, database, or external monitoring systems—while giving you a clear view of the redaction workflow.

Why use custom logging .net with GroupDocs.Redaction?

  • Compliance & Auditing: Detailed logs satisfy regulatory requirements.
  • Error Visibility: LogError and LogWarning give you immediate feedback on problems.
  • Integration Flexibility: Forward logs to existing .NET logging frameworks (Serilog, NLog, etc.).

Prerequisites

  • GroupDocs.Redaction for .NET installed (see installation below).
  • A .NET development environment (Visual Studio, VS Code, or CLI).
  • Basic C# knowledge and familiarity with file streams.

Installation

.NET CLI

dotnet add package GroupDocs.Redaction

Package Manager

Install-Package GroupDocs.Redaction

NuGet Package Manager UI
Search for “GroupDocs.Redaction” and install the latest version.

License Acquisition

  • Free Trial: Test the API with a temporary license.
  • Temporary License: Get full feature access for a limited period.
  • Purchase: Obtain a perpetual license for production deployments.

Step‑by‑Step Guide

Step 1: Define a custom logger class (log warnings c#)

Create a class that implements ILogger. This class will capture errors, warnings, and informational messages.

using System;
using GroupDocs.Redaction;

class CustomLogger : ILogger
{
    public bool HasErrors { get; private set; }

    // Log errors encountered during processing.
    public void LogError(string message)
    {
        Console.WriteLine("Error: " + message);
        HasErrors = true;
    }

    // Log warnings that may not be critical but need attention.
    public void LogWarning(string message)
    {
        Console.WriteLine("Warning: " + message);
    }

    // Log informational messages for tracking normal operations.
    public void LogInfo(string message)
    {
        Console.WriteLine("Info: " + message);
    }
}

Explanation: The HasErrors flag helps you decide whether to continue processing. The three methods correspond to the three log levels you’ll need in most redaction scenarios.

Step 2: Prepare file paths and open the source document

string sourceFile = Utils.PrepareOutputDirectory("YOUR_DOCUMENT_DIRECTORY");
string outputFile = Utils.GetOutputFile(sourceFile);

Why this matters: Using utility methods keeps your code clean and ensures the output folder exists before you attempt to save redacted document.

Step 3: Apply redactions while using the custom logger

using (Stream stream = File.Open(sourceFile, FileMode.Open, FileAccess.ReadWrite))
{
    var logger = new CustomLogger();
    
    using (Redactor redactor = new Redactor(stream, new LoadOptions(), new RedactorSettings(logger)))
    {
        // Apply a redaction to the document.
        redactor.Apply(new DeleteAnnotationRedaction());
        
        if (!logger.HasErrors)
        {
            using (Stream streamOut = File.Open(outputFile, FileMode.OpenOrCreate, FileAccess.ReadWrite))
            {
                // Save changes without rasterizing the output.
                redactor.Save(streamOut, new Options.RasterizationOptions { Enabled = false });
            }
        }
    }
}

Explanation:

  1. The Redactor is instantiated with RedactorSettings(logger), linking your CustomLogger.
  2. After applying a redaction, the code checks logger.HasErrors. If no errors occurred, the document is saved—demonstrating save redacted document logic without rasterization.

Common Pitfalls & Troubleshooting

  • Missing log output: Verify that each Log* method is correctly overridden.
  • File access exceptions: Ensure the application has read/write permissions for both source and output paths.
  • Logger not wired: The RedactorSettings(logger) parameter is essential; omitting it disables custom logging.

Practical Applications

  1. Compliance Reporting: Export log entries to a CSV or database for audit trails.
  2. Error Tracking: Quickly locate problematic files by scanning LogError output.
  3. Workflow Automation: Trigger downstream processes (e.g., notifying a compliance officer) when LogWarning is invoked.

Performance Considerations

  • Dispose streams promptly to free memory, especially when processing large batches.
  • Monitor CPU & memory during bulk redactions; consider processing documents in parallel with careful logger synchronization.
  • Stay updated: Newer versions of GroupDocs.Redaction often include performance optimizations and additional logging hooks.

Conclusion

By implementing a custom logger c#, you gain granular insight into every step of the redaction pipeline, making it easier to meet compliance standards and debug issues. The approach shown here works seamlessly with GroupDocs.Redaction for .NET and can be extended to integrate with any .NET logging framework you already use.

Frequently Asked Questions

Q: What is the purpose of custom logging with GroupDocs.Redaction?
A: Custom logging helps track and manage redactions for compliance, error tracking, and workflow optimization.

Q: How do I handle errors using a custom logger?
A: Implement LogError in your CustomLogger class; the HasErrors flag lets you halt processing if needed.

Q: Can custom logging be integrated with other systems?
A: Yes, you can forward log messages to CRM, ERP, or centralized monitoring tools by extending the logger methods.

Q: What are some common pitfalls when implementing custom logging?
A: Incorrect method implementations, missing RedactorSettings(logger), and file permission issues are the most frequent.

Q: How does custom logging improve document redaction workflows?
A: Detailed logs provide real‑time visibility, simplify troubleshooting, and satisfy audit requirements.

Resources

Last Updated: 2026-03-28
Tested With: GroupDocs.Redaction 23.11 for .NET
Author: GroupDocs