How to Handle PSD Core Exceptions in .NET

Aspose.PSD FOSS for .NET defines two exception types: PsdLoadException, thrown while parsing a PSD/PSB document, and PsdSaveException, thrown while writing one. Both derive from System.Exception and support a message-only constructor and a message-plus-inner-exception constructor.

Step-by-Step Guide

Step 1: Install the Package

git clone https://github.com/aspose-psd-foss/Aspose.PSD-FOSS-for-.NET.git
cd Aspose.PSD-FOSS-for-.NET
dotnet build

Step 2: Import Required Classes

using Aspose.PSD.FileFormats.Psd;

Step 3: Catch Load-Time Failures

PsdLoadException is thrown when a document’s structure fails validation — for example, an unsupported PSD/PSB version, a section length that exceeds the enclosing section’s declared boundary, or truncated stream data:

try
{
    using var image = PsdImage.Load("input.psd");
}
catch (PsdLoadException ex)
{
    Console.WriteLine($"Failed to load PSD/PSB file: {ex.Message}");
}

Step 4: Catch Save-Time Failures

PsdSaveException is thrown while writing a document — for example, when a string value exceeds the length a PSD Pascal string field can hold:

try
{
    image.Save("output.psd");
}
catch (PsdSaveException ex)
{
    Console.WriteLine($"Failed to save PSD/PSB file: {ex.Message}");
}

Step 5: Inspect an Inner Exception

Both exception types have a constructor that wraps an inner exception (used internally, for example, when an I/O error interrupts reading the file structure). Check InnerException for the underlying cause:

try
{
    using var image = PsdImage.Load("input.psd");
}
catch (PsdLoadException ex) when (ex.InnerException != null)
{
    Console.WriteLine($"Underlying I/O error: {ex.InnerException.Message}");
}

Common Issues and Fixes

PsdLoadException with a message about an unsupported version. The file’s declared PSD version field is neither the standard PSD nor the large-document PSB value. Confirm the file is a genuine, uncorrupted PSD/PSB document.

PsdLoadException with a message about a section length exceeding a boundary. The file’s internal length fields are inconsistent with its actual size — this usually indicates a truncated or corrupted file rather than an unsupported variant.

PsdSaveException about a Pascal string length. A string value (such as a layer or resource name) exceeds 255 bytes, the maximum a PSD Pascal string field can encode. Shorten the value before saving.

Frequently Asked Questions

Do PsdLoadException and PsdSaveException share a common base exception type?

No — both derive directly from System.Exception, not from each other or a shared Aspose.PSD base exception class.

Can PsdSaveException occur for reasons other than a long string value?

The confirmed throw site in this FOSS build is the Pascal-string-length check. Other save-time I/O failures (for example, a destination stream that cannot be written to) surface as the underlying .NET exception type rather than being wrapped in PsdSaveException.

Will catching `Exception` also catch these two types?

Yes, since both derive from System.Exception — but catching the specific types lets you distinguish load failures from save failures.