feat(能力完善): 完善转换保真，修复交互缺陷

ofdgo_pdf_attachment.go

@@ -0,0 +1,49 @@
+// Copyright 2025-2026 肖其顿 (XIAO QI DUN)
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package ofdgo
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/xiaoqidun/pdfgo"
+)
+
+// documentAttachments 导入文档名称树中的附件，与注解及动作引用共用附件资源
+// 入参: ctx 取消上下文
+// 返回: error 名称树、附件读取或写入错误
+func (p *pdfImporter) documentAttachments(ctx context.Context) error {
+	return p.reader.WalkEmbeddedFiles(ctx, func(_ string, file pdfgo.FileSpecification) error {
+		if file.Embedded == nil {
+			if p.warning == nil {
+				return fmt.Errorf("PDF embedded file has no embedded data")
+			}
+			p.warning(pdfgo.Diagnostic{Message: "PDF embedded file without embedded data ignored"})
+			return nil
+		}
+		data, err := file.Embedded.DecodeContext(ctx)
+		if err != nil {
+			var unsupported *pdfgo.UnsupportedError
+			if p.warning != nil && errors.As(err, &unsupported) {
+				p.warning(pdfgo.Diagnostic{Message: "PDF document attachment not transferred to OFD: " + err.Error()})
+				return nil
+			}
+			return err
+		}
+		_, err = p.attachmentFile(file.Name, data)
+		return err
+	})
+}