IronXLを使用して C# で DataGridView を Excel にエクスポートする方法

void Form1_Load(object sender, EventArgs e)
{
    var dt = new DataTable();

    // Define columns with the appropriate .NET type
    dt.Columns.Add("EmployeeID", typeof(int));
    dt.Columns.Add("Name", typeof(string));
    dt.Columns.Add("Department", typeof(string));
    dt.Columns.Add("Salary", typeof(decimal));

    // Add sample rows
    dt.Rows.Add(101, "Sarah Johnson", "Engineering", 85000m);
    dt.Rows.Add(102, "Michael Chen", "Marketing", 72000m);
    dt.Rows.Add(103, "Emily Davis", "Finance", 91000m);
    dt.Rows.Add(104, "James Wilson", "Engineering", 78000m);

    DataGridView1.DataSource = dt;
}

Option Strict On



Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Dim dt As New DataTable()

    ' Define columns with the appropriate .NET type
    dt.Columns.Add("EmployeeID", GetType(Integer))
    dt.Columns.Add("Name", GetType(String))
    dt.Columns.Add("Department", GetType(String))
    dt.Columns.Add("Salary", GetType(Decimal))

    ' Add sample rows
    dt.Rows.Add(101, "Sarah Johnson", "Engineering", 85000D)
    dt.Rows.Add(102, "Michael Chen", "Marketing", 72000D)
    dt.Rows.Add(103, "Emily Davis", "Finance", 91000D)
    dt.Rows.Add(104, "James Wilson", "Engineering", 78000D)

    DataGridView1.DataSource = dt
End Sub

void btnExport_Click(object sender, EventArgs e)
{
    var workbook = WorkBook.Create();
    var sheet = workbook.DefaultWorkSheet;

    // Write column headers to row index 0
    for (int col = 0; col < DataGridView1.Columns.Count; col++)
    {
        sheet.SetCellValue(0, col, DataGridView1.Columns[col].HeaderText);
    }

    // Write data rows starting at row index 1
    for (int row = 0; row < DataGridView1.Rows.Count; row++)
    {
        for (int col = 0; col < DataGridView1.Columns.Count; col++)
        {
            object? cellValue = DataGridView1.Rows[row].Cells[col].Value;
            if (cellValue is not null)
            {
                sheet.SetCellValue(row + 1, col, cellValue.ToString()!);
            }
        }
    }

    string outputPath = "EmployeeData.xlsx";
    workbook.SaveAs(outputPath);
    MessageBox.Show("Export complete. File saved to: " + outputPath, "Success");
}

Private Sub btnExport_Click(sender As Object, e As EventArgs)
    Dim workbook = WorkBook.Create()
    Dim sheet = workbook.DefaultWorkSheet

    ' Write column headers to row index 0
    For col As Integer = 0 To DataGridView1.Columns.Count - 1
        sheet.SetCellValue(0, col, DataGridView1.Columns(col).HeaderText)
    Next

    ' Write data rows starting at row index 1
    For row As Integer = 0 To DataGridView1.Rows.Count - 1
        For col As Integer = 0 To DataGridView1.Columns.Count - 1
            Dim cellValue As Object = DataGridView1.Rows(row).Cells(col).Value
            If cellValue IsNot Nothing Then
                sheet.SetCellValue(row + 1, col, cellValue.ToString())
            End If
        Next
    Next

    Dim outputPath As String = "EmployeeData.xlsx"
    workbook.SaveAs(outputPath)
    MessageBox.Show("Export complete. File saved to: " & outputPath, "Success")
End Sub

void ExportWithFormatting()
{
    var workbook = WorkBook.Create();
    var sheet = workbook.DefaultWorkSheet;

    // Write column headers
    for (int col = 0; col < DataGridView1.Columns.Count; col++)
    {
        sheet.SetCellValue(0, col, DataGridView1.Columns[col].HeaderText);
    }

    // Style the header row: bold white text on blue background
    var headerRange = sheet.GetRange("A1:D1");
    headerRange.Style.Font.Bold = true;
    headerRange.Style.SetBackgroundColor("#4472C4");
    headerRange.Style.Font.SetColor("#FFFFFF");

    // Locate the Salary column index
    int salaryColIndex = -1;
    for (int i = 0; i < DataGridView1.Columns.Count; i++)
    {
        if (string.Equals(DataGridView1.Columns[i].HeaderText, "Salary",
            StringComparison.OrdinalIgnoreCase))
        {
            salaryColIndex = i;
            break;
        }
    }

    // Write data rows, preserving numeric types
    for (int row = 0; row < DataGridView1.Rows.Count; row++)
    {
        if (DataGridView1.Rows[row].IsNewRow) continue;

        for (int col = 0; col < DataGridView1.Columns.Count; col++)
        {
            object? cellValue = DataGridView1.Rows[row].Cells[col].Value;
            if (cellValue is null) continue;

            int targetRow = row + 1;

            if (col == salaryColIndex)
            {
                // Write salary as a true numeric decimal
                if (decimal.TryParse(cellValue.ToString(),
                    System.Globalization.NumberStyles.Number,
                    System.Globalization.CultureInfo.InvariantCulture,
                    out decimal decValue))
                {
                    sheet.SetCellValue(targetRow, col, decValue);
                }
                else
                {
                    sheet.SetCellValue(targetRow, col, cellValue.ToString()!);
                }
            }
            else
            {
                sheet.SetCellValue(targetRow, col, cellValue.ToString()!);
            }
        }
    }

    // Apply currency format to the salary column data range
    var salaryRange = sheet.GetRange("D2:D5");
    salaryRange.FormatString = "$#,##0";

    workbook.SaveAs("FormattedEmployeeData.xlsx");
}

Option Strict On



Sub ExportWithFormatting()
    Dim workbook = WorkBook.Create()
    Dim sheet = workbook.DefaultWorkSheet

    ' Write column headers
    For col As Integer = 0 To DataGridView1.Columns.Count - 1
        sheet.SetCellValue(0, col, DataGridView1.Columns(col).HeaderText)
    Next

    ' Style the header row: bold white text on blue background
    Dim headerRange = sheet.GetRange("A1:D1")
    headerRange.Style.Font.Bold = True
    headerRange.Style.SetBackgroundColor("#4472C4")
    headerRange.Style.Font.SetColor("#FFFFFF")

    ' Locate the Salary column index
    Dim salaryColIndex As Integer = -1
    For i As Integer = 0 To DataGridView1.Columns.Count - 1
        If String.Equals(DataGridView1.Columns(i).HeaderText, "Salary", StringComparison.OrdinalIgnoreCase) Then
            salaryColIndex = i
            Exit For
        End If
    Next

    ' Write data rows, preserving numeric types
    For row As Integer = 0 To DataGridView1.Rows.Count - 1
        If DataGridView1.Rows(row).IsNewRow Then Continue For

        For col As Integer = 0 To DataGridView1.Columns.Count - 1
            Dim cellValue As Object = DataGridView1.Rows(row).Cells(col).Value
            If cellValue Is Nothing Then Continue For

            Dim targetRow As Integer = row + 1

            If col = salaryColIndex Then
                ' Write salary as a true numeric decimal
                Dim decValue As Decimal
                If Decimal.TryParse(cellValue.ToString(), Globalization.NumberStyles.Number, Globalization.CultureInfo.InvariantCulture, decValue) Then
                    sheet.SetCellValue(targetRow, col, decValue)
                Else
                    sheet.SetCellValue(targetRow, col, cellValue.ToString())
                End If
            Else
                sheet.SetCellValue(targetRow, col, cellValue.ToString())
            End If
        Next
    Next

    ' Apply currency format to the salary column data range
    Dim salaryRange = sheet.GetRange("D2:D5")
    salaryRange.FormatString = "$#,##0"

    workbook.SaveAs("FormattedEmployeeData.xlsx")
End Sub

void ExportToCsv()
{
    var workbook = WorkBook.Create();
    var sheet = workbook.DefaultWorkSheet;

    for (int col = 0; col < DataGridView1.Columns.Count; col++)
    {
        sheet.SetCellValue(0, col, DataGridView1.Columns[col].HeaderText);
    }

    for (int row = 0; row < DataGridView1.Rows.Count; row++)
    {
        if (DataGridView1.Rows[row].IsNewRow) continue;

        for (int col = 0; col < DataGridView1.Columns.Count; col++)
        {
            object? cell = DataGridView1.Rows[row].Cells[col].Value;
            if (cell is not null)
                sheet.SetCellValue(row + 1, col, cell.ToString()!);
        }
    }

    // Saving with a .csv extension produces a comma-separated file
    workbook.SaveAs("EmployeeData.csv");
}

Sub ExportToCsv()
    Dim workbook = WorkBook.Create()
    Dim sheet = workbook.DefaultWorkSheet

    For col As Integer = 0 To DataGridView1.Columns.Count - 1
        sheet.SetCellValue(0, col, DataGridView1.Columns(col).HeaderText)
    Next

    For row As Integer = 0 To DataGridView1.Rows.Count - 1
        If DataGridView1.Rows(row).IsNewRow Then Continue For

        For col As Integer = 0 To DataGridView1.Columns.Count - 1
            Dim cell As Object = DataGridView1.Rows(row).Cells(col).Value
            If cell IsNot Nothing Then
                sheet.SetCellValue(row + 1, col, cell.ToString())
            End If
        Next
    Next

    ' Saving with a .csv extension produces a comma-separated file
    workbook.SaveAs("EmployeeData.csv")
End Sub