使用C#将DataGridView数据导出为Excel

private int rowIndex = 0;
private int colIndex = 0;
private int rowIndexOfLineState = 0;
private int rowIndexOfLineEnd = 0;
private int dataGridViewRows = 0;
private int dataGridViewCols = 0;
Excel.Application excel = null;
Excel.Workbook book = null;
Excel._Worksheet sheet = null;

public void ToExcel(DataGridView dataGridView, String strTitil)
        {
            try
            {
                if (dataGridView == null)
                    return;
                dataGridViewCols = dataGridView.Columns.Count;
                excel = new Excel.Application();
                book = excel.Workbooks.Add(System.Reflection.Missing.Value);
                sheet = book.Sheets["sheet1"] as Excel.Worksheet;
                book = excel.ActiveWorkbook;
                sheet = (Excel.Worksheet)excel.ActiveSheet;
                Excel.Range range;
                //写表头标题
                rowIndex = 1;
                range = excel.Range[sheet.Cells[rowIndex, 1], sheet.Cells[rowIndex + 1, dataGridViewCols]];
                range.Merge(false);
                range.HorizontalAlignment = Excel.XlVAlign.xlVAlignCenter;
                range.Value = strTitil;
                rowIndex = rowIndex + 2;