NPOI简单示例2—合并表头

/// <summary>
/// 创建sheet中的行和列
/// </summary>
/// <param name="sheet"></param>
/// <param name="rowcount"></param>
/// <param name="cellcount"></param>
/// <returns></returns>
private static ISheet Create(ISheet sheet, int rowcount, int cellcount)
{
for (int i = 0; i < rowcount; i++)
{
IRow targetRow = null;
targetRow = sheet.CreateRow(i);
for (int j = 0; j < cellcount; j++)
{
IRow row = sheet.GetRow(i);
ICell cell = row.CreateCell(j);
}
}
return sheet;
}

public static MemoryStream CommonBaseExcel(DataTable dtsource)
{
HSSFWorkbook workbook = new HSSFWorkbook();
ISheet sheet = workbook.CreateSheet("test_01");
IDataFormat format = workbook.CreateDataFormat();

ICellStyle style = workbook.CreateCellStyle();
style.VerticalAlignment = VerticalAlignment.Center;
style.Alignment = HorizontalAlignment.Center;

int rowCount = dtsource.Rows.Count + 1;
int cellCount = dtsource.Columns.Count;
Create(sheet, rowCount, cellCount);

for (int i = 0; i < dtsource.Columns.Count; i++)
{
string cellValue = dtsource.Columns[i].ColumnName.ToString();
//sheet.GetRow(0).GetCell(i).SetCellValue(cellValue);
ICell cell = sheet.GetRow(0).GetCell(i);
cell.SetCellValue(cellValue);
cell.CellStyle = style;
}
for (int i = 0; i < dtsource.Rows.Count; i++)
{
int row = i + 1;
for (int j = 0; j < dtsource.Columns.Count; j++)
{
string cellValue = dtsource.Rows[i][j].ToString();
ICell cell = sheet.GetRow(row).GetCell(j);
cell.SetCellValue(cellValue);
cell.CellStyle = style;
}

}
sheet.AddMergedRegion(new CellRangeAddress(0, 1, 0,0));
sheet.AddMergedRegion(new CellRangeAddress(0, 0, 1,2));

using (MemoryStream ms = new MemoryStream())
{
FileStream file = new FileStream(@"F:\test.xls", FileMode.Create);
workbook.Write(file);
file.Close();
return ms;
}

}

public int Export(ExportBLLRequest body, ref string fileData, ref string folderName)
{
string userId = body.UserId;
string companyId = body.CompanyId;

//获取要导出的数据
var users = DbService._User.LoadEntities(p => p.IsValid == true).ToList();

DataTable dt = new DataTable();
dt.Columns.Add("登录名", typeof(string));
dt.Columns.Add("密码", typeof(string));
dt.Columns.Add("", typeof(string));

var row0 = dt.NewRow();
row0[0] = "";
row0[1] = "密码1";
row0[2] = "密码2";
dt.Rows.Add(row0);

foreach (var userItem in users)
{
#region

var row = dt.NewRow();
int rowIndex = 0;
row[rowIndex] = userItem.UserName;
rowIndex++;
row[rowIndex] = userItem.Password + "1";
rowIndex++;
row[rowIndex] = userItem.Password+"2";
rowIndex++;
dt.Rows.Add(row);

#endregion

}
var ms = CommonBaseExcel(dt);
var data = ms.ToArray();
fileData = Convert.ToBase64String(data);

return 0;
}