在按钮的click事件中输入如下代码，即可以实现写入Excel文件。
写Excel文件时，还要把项目文件夹的权限进行设置，对iuser_machine用户有可写的权限。
private void Button1_Click(object sender, System.EventArgs e)
{string filename="";
Excel.ApplicationClass oExcel;
oExcel = new Excel.ApplicationClass();
oExcel.UserControl = false;
Excel.WorkbookClass wb = (Excel.WorkbookClass) oExcel.Workbooks.Add(System.Reflection.Missing.Value);
for(int i = 1;i <= 5; i++)
{
oExcel.Cells[i,1]=i.ToString();
oExcel.Cells[i,2]="'第2列";
oExcel.Cells[i,3]="'第3列";
oExcel.Cells[i,4]="'第4列";
}
wb.Saved = true;
filename= Request.PhysicalApplicationPath + "test.xls";
oExcel.ActiveWorkbook.SaveCopyAs(filename);
oExcel.Quit();
System.GC.Collect();
Response.Redirect( Request.ApplicationPath + "/test.xls");
}
