ValidatePdfR 方法

ValidatePdfR 會走訪已開啟文件，尋找 ISO 23504-1:2020 定義的檔案格式標記

• 檔案結尾附近的 %PDF-raster-x.y 版本識別註解（§5）。
• A header line of the form %PDF-1.4, %PDF-1.5, %PDF-1.6, or %PDF-1.7 (§6.2.2) for unencrypted files, or %PDF-2.0 (§6.2.3) for encrypted files.
• The absence of object streams (/Type /ObjStm — §6.2.4).
• Catalog dictionary compliance with the §6.3 white list (Version / ViewerPreferences / PageLayout / PageMode / AcroForm / Metadata; everything else triggers pvriProhibitedCatalogEntry).
• Document Information Dictionary compliance with the §6.4.3 white list (Creator / Producer / CreationDate / ModDate; Title / Author / Subject / Keywords / Trapped trigger pvriProhibitedInfoEntry).
• An XMP metadata stream in the catalog (§6.4).
• A trailer /ID array.

The result is a TPdfRValidationResult record:

• Conformance — prc1 (PDF/R-1 marker found), prcNone (no marker), or prcUnknown (parse failed or document inactive).
• Issues — a TPdfRValidationIssues set with zero or more values: pvriMissingVersionMarker, pvriBadHeader, pvriObjStmPresent, pvriProhibitedCatalogEntry, pvriProhibitedInfoEntry, pvriInfoXmpMismatch, pvriMissingXmpMetadata, pvriMissingTrailerId.

ValidatePdfR is a read-only file-format inspection. PDF/R-1 compliance has strict structural requirements that this method does not check — per-page Contents structure, MediaBox form, allowed filters, generation-zero indirect references, strip layout. Pair with a TWAIN Working Group PDF/R validator for those content-level checks.

• 版本標記檢查會在檔案任意位置尋找 %PDF-raster- 子字串。ISO 23504-1 §5 指出這個標記放在 trailer dictionary 與 startxref 之間，但為了容忍稍微不標準的產生器，驗證器也接受其他位置
• 對未啟用的文件呼叫 ValidatePdfR 會傳回 Conformance = prcUnknown 且 Issues 為空的記錄
• Encryption is permitted by §6.2.3 (with a %PDF-2.0 header), so the validator does NOT flag the trailer /Encrypt key as a non-conformance. Source PDFs encrypted under PDF 1.x would still fail because of the header check.