public  void ExportToExcel(string filename, System.Data .DataTable dt,string excelname)
{if(dt==null) return;string saveFileName="";
bool fileSaved=false;
SaveFileDialog saveDialog=new SaveFileDialog();
saveDialog.DefaultExt ="xls";
saveDialog.Filter="Excel文件|*.xls";
saveDialog.FileName =filename;
saveDialog.ShowDialog();
saveFileName=saveDialog.FileName;
if(saveFileName.IndexOf(":")<0) return; //被点了取消
   
Excel.Application xlApp=new Excel.Application();if(xlApp==null)
{
MessageBox.Show("无法创建Excel对象，可能您的机子未安装Excel");
return;
}Excel.Workbooks workbooks=xlApp.Workbooks;
Excel.Workbook workbook=workbooks.Add(Excel.XlWBATemplate.xlWBATWorksheet);
Excel.Worksheet worksheet=(Excel.Worksheet)workbook.Worksheets[1];//取得sheet1
Excel.Range range;
long totalCount=dt.Rows.Count;
long rowRead=0;
float percent=0;worksheet.Cells[1,1]=excelname;
//写入字段
for(int i=0;i<dt.Columns.Count;i++)
{
worksheet.Cells[2,i+1]=dt.Columns.ColumnName;  
range=(Excel.Range)worksheet.Cells[2,i+1];
range.Interior.ColorIndex = 15;
range.Font.Bold = true;
  
}
//写入数值
//this.CaptionVisible = true;
for(int r=0;r<dt.Rows.Count;r++)
{
for(int i=0;i<dt.Columns.Count;i++)
{
worksheet.Cells[r+3,i+1]=dt.Rows[r];     
}
rowRead++;
percent=((float)(100*rowRead))/totalCount;   
//this.Capti+ percent.ToString("0.00")  +"%]...";
System.Windows.Forms .Application.DoEvents();
}
//this.CaptionVisible = false;
//this.CaptionText = oldCaption;range=worksheet.get_Range(worksheet.Cells[2,1],worksheet.Cells[dt.Rows.Count+2,dt.Columns.Count]);
range.BorderAround(Excel.XlLineStyle.xlContinuous,Excel.XlBorderWeight.xlThin,Excel.XlColorIndex.xlColorIndexAutomatic,null);
   
range.Borders[Excel.XlBordersIndex.xlInsideHorizontal].ColorIndex = Excel.XlColorIndex.xlColorIndexAutomatic;
range.Borders[Excel.XlBordersIndex.xlInsideHorizontal].LineStyle =Excel.XlLineStyle.xlContinuous;
range.Borders[Excel.XlBordersIndex.xlInsideHorizontal].Weight =Excel.XlBorderWeight.xlThin;if(dt.Columns.Count>1)
{
range.Borders[Excel.XlBordersIndex.xlInsideVertical].ColorIndex =Excel.XlColorIndex.xlColorIndexAutomatic;
range.Borders[Excel.XlBordersIndex.xlInsideVertical].LineStyle = Excel.XlLineStyle.xlContinuous;
range.Borders[Excel.XlBordersIndex.xlInsideVertical].Weight = Excel.XlBorderWeight.xlThin;
}if(saveFileName!="")
{   
try
{
workbook.Saved =true;   
workbook.SaveCopyAs(saveFileName);
fileSaved=true;
}
catch(Exception ex)
{
fileSaved=false;
MessageBox.Show("导出文件时出错,文件可能正被打开！\n"+ex.Message);
}
}
else
{
fileSaved=false;
}   
xlApp.Quit();   
GC.Collect();//强行销毁
if(fileSaved && File.Exists(saveFileName)) System.Diagnostics.Process.Start(saveFileName);
   }