datatable导出excel

public static void DataTabletoExcel(System.Data.DataTable tmpDataTable, string strFileName)
{
if (tmpDataTable == null)
{
return;
}

int rowNum = tmpDataTable.Rows.Count;
int columnNum = tmpDataTable.Columns.Count;
int rowIndex = 1;
int columnIndex = 0;

Application xlApp = new ApplicationClass();
xlApp.DefaultFilePath = "";
xlApp.DisplayAlerts = true;
xlApp.SheetsInNewWorkbook = 1;
Workbook xlBook = xlApp.Workbooks.Add(true);

//将DataTable的列名导入Excel表第一行
foreach (DataColumn dc in tmpDataTable.Columns)
{
columnIndex++;
xlApp.Cells[rowIndex, columnIndex] = dc.ColumnName;
}

//将DataTable中的数据导入Excel中
for (int i = 0; i < rowNum; i++)
{
rowIndex++;
columnIndex = 0;
for (int j = 0; j < columnNum; j++)
{
columnIndex++;
xlApp.Cells[rowIndex, columnIndex] = tmpDataTable.Rows[i][j].ToString();
}
}

xlBook.SaveCopyAs(strFileName);
}