Flutter Multi Image Pick and inserting in PDF table only last list inserted

Question

I am new to flutter and I am in process of making an app to select multiple images using image_picker package and inserting it into the pdf table. I am able to get the images and make a list based on the number of rows required, however when the pdf is created, the rows are correct but only the last list in the nested lists is displayed repeatedly. My code is as below. Any suggestions?

Page from where images are loaded

class imagecollager extends StatefulWidget {
  @override
  _imagecollagerState createState() => _imagecollagerState();
}

class _imagecollagerState extends State<imagecollager> {
  String pdfFile = '';

  final ImagePicker imagePicker = ImagePicker();
  List<XFile>? imageFileList = [];

  int numbofcol = 3;// Number of column in Row
  int numbofpgs =1; // number of pages
 var numboflist = 0; // number of rows
  List imagelist=[];
  List<List> imagedata=[];
  List<XFile>?  selectedImages =[];
  String selimages = "";
  var  imagefilestart=0;
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [

           TextButton(
                onPressed: () async {
                  selectImages();
                },
                child: Text('Load Image')),
            Text(selimages),
            TextButton(
                onPressed: () async {
                 sortImages();
                },
                child: Text('Create a Pdf')),
          ],
        ),
      ),
    );
  }


  void selectImages() async {
    imageFileList!.clear();
  selectedImages = await imagePicker.pickMultiImage();
    if (selectedImages!.isNotEmpty) {

      imageFileList!.addAll(selectedImages!);
    }
    setState(() {
    });

  setState(() {
    selimages =   imageFileList!.length.toString();
    imagefilestart=0;
  });
  }

void sortImages() async {
  imagedata.clear();
  numboflist=(imageFileList!.length/numbofcol).ceil(); //
    for (var row = 0; row < numboflist; row++) {
    imagelist.clear();

    for (var j = 0; j < numbofcol; j++) {

      File imageFile = File(imageFileList![imagefilestart].path);
      Uint8List imageRaw = await imageFile.readAsBytes();
      imagelist.add(imageRaw);
         imagefilestart= imagefilestart+1 ;
     if(imagefilestart==imageFileList!.length) break ;

    }

    imagedata.insert(row, imagelist);
   
  }

 
   final pdfFile = await PdfApi.generateImage(imagedata);
PdfApi.openFile(pdfFile);

}

}

Pdf processing code as below

class PdfApi {
  static Future<File> generateCenteredText(String text) async {
    final pdf = Document();

    pdf.addPage(Page(
      build: (context) => Center(
        child: Text(text, style: const TextStyle(fontSize: 48)),
      ),
    ));

    return saveDocument(name: 'my_example.pdf', pdf: pdf);
  }
  
  static Future<File> generateImage( var imagedata) async {
    final pdf = Document();
  
    final pageTheme = PageTheme(
      pageFormat: PdfPageFormat.a4,
    
    );

    pdf.addPage(
      MultiPage(
        pageTheme: pageTheme,
        build: (context) => [
          for (var i = 0; i < imagedata.length; i++)
            Table(
                border: TableBorder.all(
                  color: PdfColors.black,
                  //style: BorderStyle.solid,
                  width: 0.5,
                ),
                children: [

                  TableRow(children: [
                    //for(var item in imagedata[i] )
                      for (var j = 0; j < imagedata[i].length; j++)
                      Image(MemoryImage(imagedata[i][j]),
                      )
                  ]),
        ],
      ),
                      ]
      )
    );

    return saveDocument(name: 'my_example.pdf', pdf: pdf);
  }


  static Future<File> saveDocument({
    required String name,
    required Document pdf,
  }) async {
    final bytes = await pdf.save();
    final dir = await getApplicationDocumentsDirectory();
    final file = File('${dir.path}/$name');
    await file.writeAsBytes(bytes);
    return file;
  }

  static Future openFile(File file) async {
    final url = file.path;
    await OpenFile.open(url);
  }
}

Answer 1

I think it was a referencing issue when I try to clear a list in loop. When I changed the below

imagelist.clear();

to

imagelist=[];

it started to work as required.