C#从datagridview填充excel直到到达某一列

using Excel = Microsoft.Office.Interop.Excel;

Excel.Application excelApp = new Excel.Application();
Excel.Workbook workbook = excelApp.Workbooks.Add();
Excel.Worksheet worksheet = workbook.ActiveSheet;

// 获取DataGridView的列数和行数
int columnCount = dataGridView1.ColumnCount;
int rowCount = dataGridView1.RowCount;

// 填充表头
for (int i = 0; i < columnCount; i++)
{
    worksheet.Cells[1, i + 1] = dataGridView1.Columns[i].HeaderText;
}

// 填充数据
for (int i = 0; i < rowCount; i++)
{
    for (int j = 0; j < columnCount; j++)
    {
        worksheet.Cells[i + 2, j + 1] = dataGridView1.Rows[i].Cells[j].Value.ToString();
    }
}

for (int i = 0; i < rowCount; i++)
{
    for (int j = 0; j < columnCount; j++)
    {
        if (j < 4) // 只填充前4列
        {
            worksheet.Cells[i + 2, j + 1] = dataGridView1.Rows[i].Cells[j].Value.ToString();
        }
    }
}

workbook.SaveAs("路径/文件名.xlsx");
workbook.Close();
excelApp.Quit();