导出excel⽂件解决科学计数法问题datagridview导出字符串变
数字问题
在winform程序开发时，处理的办法就是在导出的过程中，开始试了 处理excel对象的格式
mysheet.Cells.NumberFormat = "@";
后来没有成功。最后还是⽤了逐条纪录进⾏字符格式转化的⽅法，即添加“'”.
/// <summary>
///⽅法，导出DataGridView中的数据到Excel⽂件
/// </summary>
/// <remarks>
/// add com "Microsoft Excel 11.0 Object Library"
/// using Excel=Microsoft.Office.Interop.Excel;
/
// using System.Reflection;
/// </remarks>
/// <param name= "dgv"> DataGridView </param>
public static void dv2excel_bar(DataGridView dgv)
{
#region  验证可操作性
//申明保存对话框
SaveFileDialog dlg = new SaveFileDialog();
//默然⽂件后缀
dlg.DefaultExt = "xls ";
//⽂件后缀列表
dlg.Filter = "EXCEL⽂件(*.XLS)|*.xls ";
//默然路径是系统当前路径
dlg.InitialDirectory = Directory.GetCurrentDirectory();
//打开保存对话框
if (dlg.ShowDialog() == DialogResult.Cancel) return;
//返回⽂件路径
getsavefilenamestring fileNameString = dlg.FileName;
//验证strFileName是否为空或值⽆效
if (fileNameString.Trim() == " ")
{ return; }
//定义表格内数据的⾏数和列数
int rowscount = dgv.Rows.Count;
int colscount = dgv.Columns.Count;
//⾏数必须⼤于0
if (rowscount <= 0)
{
MessageBox.Show("没有数据可供保存 ", "提⽰ ", MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
//列数必须⼤于0
if (colscount <= 0)
{
MessageBox.Show("没有数据可供保存 ", "提⽰ ", MessageBoxButtons.OK, MessageBoxIcon.Information);        return;
}
//⾏数不可以⼤于65536
if (rowscount > 65536)
{
MessageBox.Show("数据记录数太多(最多不能超过65536条)，不能保存 ", "提⽰ ", MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
//列数不可以⼤于255
if (colscount > 255)
{
MessageBox.Show("数据记录⾏数太多，不能保存 ", "提⽰ ", MessageBoxButtons.OK,
MessageBoxIcon.Information);
return;
}
//验证以fileNameString命名的⽂件是否存在，如果存在删除它
FileInfo file = new FileInfo(fileNameString);
if (file.Exists)
{
try
{
file.Delete();
}
catch (Exception error)
{
MessageBox.Show(error.Message, "删除失败 ", MessageBoxButtons.OK, MessageBoxIcon.Warning);            return;
}
}
#endregion
Microsoft.Office.Interop.Excel.Application objExcel = null;
Microsoft.Office.Interop.Excel.Workbook objWorkbook = null;
Microsoft.Office.Interop.Excel.Worksheet objsheet = null;
try
{
//申明对象
objExcel = new Microsoft.Office.Interop.Excel.Application();
objWorkbook = objExcel.Workbooks.Add(Missing.Value);
objsheet = (Microsoft.Office.Interop.Excel.Worksheet)objWorkbook.ActiveSheet;
objsheet.UsedRange.NumberFormatLocal = "@";
//设置EXCEL不可见
objExcel.Visible = false;
向Excel中写⼊表格的表头
int displayColumnsCount = 1;
/
/for (int i = 0; i <= dgv.ColumnCount - 1; i++)
//{
//    if (dgv.Columns[i].Visible == true)
//    {
//        objExcel.Cells[1, displayColumnsCount] = dgv.Columns[i].HeaderText.Trim();        //        displayColumnsCount++;
//    }
//}
//设置进度条
//tempProgressBar.Refresh();
//tempProgressBar.Visible  =  true;
//tempProgressBar.Minimum=1;
//tempProgressBar.Maximum=dgv.RowCount;
//tempProgressBar.Step=1;
//向Excel中逐⾏逐列写⼊表格中的数据
for (int row = 0; row <= dgv.RowCount - 1; row++)
{
//tempProgressBar.PerformStep();
displayColumnsCount = 1;
for (int col = 0; col < colscount; col++)
{
if (dgv.Columns[col].Visible == true)
{
try
{
if (col == 2)
{
objExcel.Cells[row + 2, displayColumnsCount] =
"'"+dgv.Rows[row].Cells[col].Value.ToString().Trim();
}
else
{
objExcel.Cells[row + 2, displayColumnsCount] =
dgv.Rows[row].Cells[col].Value.ToString().Trim();
}
displayColumnsCount++;
}
catch (Exception)
{
}
}
}
}
//隐藏进度条
//tempProgressBar.Visible  =  false;
/
/保存⽂件
objWorkbook.SaveAs(fileNameString, Missing.Value, Missing.Value, Missing.Value, Missing.Value,                Missing.Value, Microsoft.Office.Interop.Excel.XlSaveAsAccessMode.xlShared, Missing.Value, Missing.Value, Missing.Value,
Missing.Value, Missing.Value);
}
catch (Exception error)
{
MessageBox.Show(error.Message, "警告 ", MessageBoxButtons.OK, MessageBoxIcon.Warning);
return;
}
finally
{
//关闭Excel应⽤
if (objWorkbook != null) objWorkbook.Close(Missing.Value, Missing.Value, Missing.Value);
if (objExcel.Workbooks != null) objExcel.Workbooks.Close();
if (objExcel != null) objExcel.Quit();
objsheet = null;
objWorkbook = null;
objExcel = null;
}
MessageBox.Show(fileNameString + "\n\n导出完毕! ", "提⽰ ", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
//导出到XML(整个数据源)
public static void ExportTOXML(DataGridView gridView,string filename)
{
DataSet objSet = new DataSet();
DataTable dt = gridView.DataSource as  DataTable;
if (gridView.Rows.Count == 0)
{
MessageBox.Show("没有数据可供导出！", "提⽰", MessageBoxButtons.OK,
MessageBoxIcon.Information);
return;
}
else
{
//saveFileDialog2.Filter = "XML files (*.xml)|*.xml";
//saveFileDialog2.FilterIndex = 0;
//saveFileDialog2.RestoreDirectory = true;
saveFileDialog2.CreatePrompt = true;
//saveFileDialog2.Title = "导出⽂件保存路径";
//saveFileDialog2.FileName = null;
//saveFileDialog2.ShowDialog();
//string FileName = saveFileDialog2.FileName;
objSet.Tables.Add(dt.Copy());
if (filename.Length != 0)
{
objSet.WriteXml(filename);
MessageBox.Show("恭喜您!数据初始化已经完成：" + filename, "定稿导出完成", MessageBoxButtons.OK, MessageBoxIcon.Information);
}
}
}
    ⽆论在做web还是在写winform程序是⽼是在导出excel数据是遇到科学计数法问题，如果字符太长（如⾝份证号）在导出的excel ⽂件中就会出现长字符串的科学计数法表⽰，反复导数据是就会出现错误 。
我解决的办法是在到处是或者存储将要导出时，每条记录字符串形式处理
  在asp 中 我⼀般都是将要导出的数据放到gridview⽹格⾥，⾸先对⽹格邦定数据时 字符串形式处理，然后再⽤普通的形    式导出excel就把问题解决了。
  我的代码⾮常简单：在邦定gridview控件时在rowdatabound事件中队数据格式化