保存Excel文件示例：

支持：Office2003的xls，和Office2007的xlsx格式！

// 需要引用：Microsoft.Office.Interop.Excel.dll 10.0版本以上，支持Office2003.
// 需要引用：Microsoft.Office.Interop.Excel.dll 12.0版本的支持Office2007.

using Microsoft.Office.Interop.Excel;
using System.Runtime.InteropServices;
using System.Windows;

namespace SaveExcelSample
{
public class ExcelHelper
{

public static void SaveToExcel2003(string SaveFile)
{
// 需要引用：Microsoft.Office.Interop.Excel.dll 10.0版本以上，支持Office2003.
Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel._Workbook workBook= excel.Workbooks.Add();
Microsoft.Office.Interop.Excel._Worksheet workSheet = (Microsoft.Office.Interop.Excel._Worksheet)workBook.ActiveSheet;
object misValue = System.Reflection.Missing.Value;

int rowIndex = 1;
int colIndex = 0;

//取得标题
for (int i = 0; i < 5; i++)
{
colIndex++;
excel.Cells[1, colIndex] = "标题" + i;
}

//取得表格中的数据
for (int i = 0; i < 3; i++)
{
rowIndex++;
colIndex = 0;

for (int j = 0; j < 5; j++)
{
colIndex++;
excel.Cells[rowIndex, colIndex] = i + j;

//设置表格内容居中对齐
//workSheet.get_Range(excel.Cells[rowIndex, colIndex], excel.Cells[rowIndex, colIndex]).HorizontalAlignment = Microsoft.Office.Interop.Excel.XlVAlign.xlVAlignCenter;
}
}

excel.Visible = false; // 不显示Excel窗口

workBook.SaveAs(SaveFile, Microsoft.Office.Interop.Excel.XlFileFormat.xlWorkbookNormal, misValue,
misValue, misValue, misValue, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlExclusive,
misValue, misValue, misValue, misValue, misValue);
workBook.Close(true, misValue, misValue);
excel.Quit();

PublicMethod.Kill(excel);//调用kill当前excel进程
releaseObject(workSheet);//释放COM对象
releaseObject(workBook);
releaseObject(excel);

GC.Collect();
}

public static void SaveToExcel2007(string filePath)
{
// 创建Excel文档，保存格式 Office2007 xlsx.
// 需要引用：Microsoft.Office.Interop.Excel.dll 12.0版本的支持Office2007.
Microsoft.Office.Interop.Excel.Application excel = new Microsoft.Office.Interop.Excel.Application();
Microsoft.Office.Interop.Excel.Workbook workBook = excel.Workbooks.Add();
Microsoft.Office.Interop.Excel.Worksheet workSheet = workBook.Worksheets.Add();

//excel.DisplayAlerts = false; // 不显示告警

int rowIndex = 1;
int colIndex = 0;

//取得标题
for (int i = 0; i < 5; i++)
{
colIndex++;
workSheet.Cells[1, colIndex] = "标题" + i;
}

//取得表格中的数据
for (int i = 0; i < 3; i++)
{
rowIndex++;
colIndex = 0;

for (int j = 0; j < 5; j++)
{
colIndex++;
workSheet.Cells[rowIndex, colIndex] = i + j;
}
}

//文件保存
workSheet.SaveAs(filePath);
workBook.Close();
excel.Quit();

PublicMethod.Kill(excel);//调用kill当前excel进程
releaseObject(workSheet);//释放COM对象
releaseObject(workBook);
releaseObject(excel);

GC.Collect();
//MessageBox.Show(string.Format("{0} 文档生成成功.", filePath));
}

private static void releaseObject(object obj)
{
try
{
System.Runtime.InteropServices.Marshal.ReleaseComObject(obj);
obj = null;
}
catch
{
obj = null;
}
}

public class PublicMethod
{
[DllImport("User32.dll", CharSet = CharSet.Auto)]
public static extern int GetWindowThreadProcessId(IntPtr hwnd, out int ID);

public static void Kill(Microsoft.Office.Interop.Excel.Application excel)
{
try
{
IntPtr ptr = new IntPtr(excel.Hwnd);
int processID = 0;

GetWindowThreadProcessId(ptr, out processID);
System.Diagnostics.Process process = System.Diagnostics.Process.GetProcessById(processID);
process.Kill();
}
catch (Exception ex)
{
Console.WriteLine(" ==== " + ex.Message);
}
}
}
}
}

注：以上来源互联网，并整理。