你好，我想问一下。为什么会发生这个错误？有人能帮我吗？错误代码参数类型“BuildContext”无法分配给参数类型“String”。
代码：

Widget recentFileButton(
            BuildContext context,
            String fileName,
            String fileURL,
            String thumbnailImageName,
            String fileFrom,
            String timestamp,
            String documentID,
            String fileNotes) =>
        Container(
          margin: const EdgeInsets.only(bottom: 10),
          child: Row(
            mainAxisAlignment: MainAxisAlignment.start,
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              getPreview(fileURL, fileNotes),
              const SizedBox(width: 10),
              Expanded(
                child: InkWell(
                  onTap: () async {
                    bool _isEmwatch = false;
                    if (fileNotes == "referral letter") {
                      var uri = Uri.parse(fileURL);
                      var uuid = uri.queryParameters['uuid'];
                      var result = await DocumentRepository()
                          .doctorGetPatientReferralByUID(uuid!);
                      if (result.responseMap.clinicUID ==
                          "") {
                        _isEmwatch = true;
                      }
                      if (result.responseMap.clinicUID ==
                          "") {
                        _isEmwatch = true;
                      }
    
                      // generate and preview
                      var doc = await generateDocument(PdfPageFormat.standard,
                          result.responseMap, '', _isEmwatch);
    
                      Navigator.push(
                        context,
                        MaterialPageRoute(
                            builder: (context) => PdfPreviewPage(pdfDoc: doc)),
                      );
                    } else {
                      openDocument(context, fileURL);
                    }
                  },
                   ),
                    ],
                  ),
                ),
              ),
              const SizedBox(width: 10),
              Align(
                alignment: Alignment.topRight,
                child: IconButton(
                  icon: const Icon(
                    Icons.more_vert,
                    color: Color(0xFF021522),
                  ),
                  onPressed: () => showFileActionBottomSheet(
                      context, fileName, fileURL, documentID, fileNotes),
                ),
              )
            ],
          ),
        );

我不知道如何解决这个问题。请指导我和任何愿意帮助我解决这个问题的人。谢谢。