ValidatePdfA method

此 API 條目保留識別符號、簽名、程式碼塊和 PDF 術語的原始形式。

Inspects the currently open PDF for PDF/A compliance markers and returns a structured result with the detected conformance level plus the set of specific issues found.

ValidatePdfA walks the open document looking for every PDF/A conformance marker defined by ISO 19005-1 (with Cor.1:2007):

• An XMP metadata stream with pdfaid:part and pdfaid:conformance entries, which tells the validator what PDF/A level the document was authored against (1a, 1b, 2b, 3b, ...).
• An OutputIntent dictionary with an embedded ICC profile — required so any device-dependent colour can be reproduced on PDF/A consumers.
• The absence of encryption, which PDF/A forbids.
• A trailer /ID array (mandatory per ISO 19005-1 6.1.3).
• xmp:CreateDate and xmp:ModifyDate in the XMP packet (required when the Info dictionary holds CreationDate / ModDate values per 6.7.3 Example 2).
• The pdfaExtension:schemas container describing the pdfaid extension schema (required by 6.7.8 / Cor.1).

The result is a TPdfAValidationResult record:

• Conformance — the detected level (pac1a, pac1b, pac2b, pac3b, pacNone, or pacUnknown for a PDF/A marker without a recognised level).
• Issues — a TPdfAValidationIssues set of TPdfAValidationIssue values describing each problem found: pvaiMissingXmpMetadata, pvaiMissingPdfAIdentifier, pvaiMissingOutputIntent, pvaiMissingIccProfile, pvaiEncryptionPresent, pvaiMissingTrailerId, pvaiMissingXmpDates, and pvaiMissingExtensionSchema.

ValidatePdfA is a read-only inspection — it does not modify the document and is safe to call repeatedly. Use it before handing a PDF off to an archive system to surface non-compliance to the operator. For the common "what level is this?" check that doesn't need the issue list, prefer the lighter-weight PdfAConformance property.

• ValidatePdfA is a structural inspection — it does not enforce content-level PDF/A rules (missing embedded fonts, transparency / blend modes, smooth shading, deprecated colour spaces, etc.). For a full validator pair this method with an external tool such as veraPDF.
• Calling ValidatePdfA on an inactive document returns a record with Conformance = pacNone and an empty Issues array.
• Heavily lazy — this method only parses what it needs to answer the conformance question, so it is cheap even on large documents.

PdfAConformance, SaveAsPdfA, SaveAsPdfAToStream