How to import an excel file into Flutter DataTable (SfDataGrid)?

In this article, we will show you how to import an excel file into Flutter DataTable.

Steps to Import an Excel File into Flutter DataTable

Step 1: Extracting Data from Excel

The file picker should allow the selection of .xlsx files. Once an Excel file is selected, decode it using the Excel.decodeBytes method from the excel package. Extract the headers from the first row and the data starting from the second row. Dynamically generate columns by iterating over the headers and creating a GridColumn for each one.

  // Handle Excel file import and load data into the DataGrid.
  Future<void> importDataGridFromExcel() async {
    clearData();

    // Picking an Excel file using FilePicker.
    FilePickerResult? result = await FilePicker.platform.pickFiles(
      type: FileType.custom,
      allowedExtensions: ['xlsx'],
    );

    if (result != null) {
      Uint8List? fileBytes = result.files.first.bytes;
      if (fileBytes == null) {
        String? filePath = result.files.first.path;
        if (filePath != null) {
          fileBytes = await File(filePath).readAsBytes();
        }
      }

      if (fileBytes != null) {
        var excel = Excel.decodeBytes(fileBytes);

        for (var table in excel.tables.keys) {
          var sheet = excel.tables[table];
          // Extract headers from the first row of the sheet.
          List<String> headers =
              sheet!.row(0).map((cell) => cell!.value.toString()).toList();
          // Loop through the rows starting from the second row (skipping the header).
          for (int row = 1; row < sheet.maxRows; row++) {
            Map<String, dynamic> rowData = {};
            for (int col = 0; col < headers.length; col++) {
              rowData[headers[col]] = sheet.row(row)[col]!.value;
            }
            importedData.add(rowData);
          }
        }

        if (importedData.isNotEmpty) {
          // Generate the columns.
          columns = generateColumns(importedData[0]);
          if (mounted) {
            Navigator.push(
              context,
              MaterialPageRoute(
                builder: (context) => DataGridPage(
                  importedData: importedData,
                  columns: columns,
                ),
              ),
            );
          }
        }
      }
    }
  }

  // Clear previous data.
  void clearData() {
    importedData.clear();
    columns.clear();
  }

  // Dynamically generate columns based on the imported data.
  List<GridColumn> generateColumns(Map<String, dynamic> data) {
    List<GridColumn> columns = [];

    for (var entry in data.entries) {
      GridColumn gridColumn = GridColumn(
        columnName: entry.key,
        label: Container(
          padding: const EdgeInsets.all(8),
          alignment: Alignment.center,
          child: Text(entry.key),
        ),
      );

      columns.add(gridColumn);
    }

    return columns;
  }

Step 2: Displaying Data in SfDataGrid

Display a CircularProgressIndicator while the data is loading. Once the data is loaded, pass the prepared DataGridSource to the SfDataGrid widget to render the grid.

  late ExcelDataGridSource excelDataGridSource;
  bool isLoading = true;

  @override
  void initState() {
    super.initState();
    loadData();
  }

  // Simulate loading data and prepare the DataGrid source.
  Future<void> loadData() async {
    await Future.delayed(const Duration(seconds: 2));
    if (mounted) {
      setState(() {
        excelDataGridSource =
            ExcelDataGridSource(widget.importedData, widget.columns);
        isLoading = false;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('DataGrid'),
      ),
      body: isLoading
          ? const Center(child: CircularProgressIndicator())
          : SfDataGrid(
              source: excelDataGridSource,
              columns: widget.columns,
              columnWidthMode: ColumnWidthMode.fill,
            ),
    );
  }

You can download this example on GitHub.