How Can I Handle File Paths Longer Than 259 Characters in .NET?

Addressing .NET's 259-Character File Path Limitation

Working with files in .NET often involves dealing with the 259-character path length restriction imposed by the FileInfo class. This limitation can be overcome using several methods, depending on your .NET version.

For .NET Framework 4.6.2 and Later:

The simplest solution for applications targeting .NET Framework 4.6.2 or newer is to use the \? prefix. As documented by Microsoft, prepending \?C: (or the appropriate drive letter) to your path allows paths up to 32,767 characters. For example: "\?\C:\Verrrrrrrrrrrry long path".

For .NET Core and .NET:

.NET Core and later versions of .NET automatically support long paths, eliminating the need for manual workarounds. The framework internally handles the necessary long path syntax.

For .NET Framework Versions Before 4.6.2:

For older .NET Framework versions (prior to 4.6.2), a combined approach is required: using the long path syntax with Unicode-compatible Win32 API calls via P/Invoke. This can be achieved with:

<code class="language-csharp">System.IO.Path.Combine("\\?\", System.IO.Path.GetFullPath(path));</code>

Remember that using this method requires utilizing Unicode API functions for proper long path compatibility, as per Microsoft's recommendations.

Important Notes:

Even with long path support enabled, Microsoft's BCL Team blog highlights potential subtleties. Some Windows APIs may behave differently with long paths; issues like path normalization failures and incompatibilities with certain applications or the Windows shell itself might arise. Microsoft is actively working to improve compatibility and support for extended file paths in future Windows releases.

The above is the detailed content of How Can I Handle File Paths Longer Than 259 Characters in .NET?. For more information, please follow other related articles on the PHP Chinese website!