DataTable导出excel 设置单元格格式

public static void DataTableExcel(DataTable dtData, String FileName)
{
    System.Web.UI.WebControls.GridView dgExport = null;
    System.Web.HttpContext curContext = System.Web.HttpContext.Current;
    System.IO.StringWriter strWriter = null;
    System.Web.UI.HtmlTextWriter htmlWriter = null;

    if (dtData != null)
    {
        //设置编码和附件格式 作用是中文文件名乱码
        //System.Web.HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8)
        curContext.Response.ContentType = "application/ms-excel"; // "application nd.ms-excel";
        curContext.Response.ContentEncoding = System.Text.Encoding.Default;
        curContext.Response.Charset = "gb2312";
        curContext.Response.AddHeader("content-disposition", "attachment;filename=" + System.Web.HttpUtility.UrlEncode(FileName, System.Text.Encoding.UTF8) + ".xls");
        //导出Excel文件 
        strWriter = new System.IO.StringWriter();
        htmlWriter = new System.Web.UI.HtmlTextWriter(strWriter);

        //为了解决dgData中可能进行了分页的情况,需要重新定义一个无分页的GridView 
        dgExport = new System.Web.UI.WebControls.GridView();
        dgExport.DataSource = dtData;
        dgExport.AllowPaging = false;
        dgExport.DataBind();

        //设置导出格式为文本格式防止丢失数据
        dgExport.Attributes.Add("style", "vnd.ms-excel.numberformat:@");

        //设置excel单元格格式防止转换数据丢失数字
        //for (int i = 0; i < dtData.Rows.Count; i++)
        //{
        //    for (int j = 0; j < dtData.Columns.Count; j++)
        //    {
        //        dgExport.Rows[i].Cells[j].Attributes.Add("style", "vnd.ms-excel.numberformat:@");
        //    }
        //}

        //下载到客户端 
        dgExport.RenderControl(htmlWriter);
        curContext.Response.Write("<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />" + strWriter.ToString());
        curContext.Response.End();
    }

另:

取行一般用rowfilter

DataTable datSource;//数据源表
//过滤表
DataView davTemp = new DataView(datSource, "过滤条件", "排序字段", DataViewRowState.各种 状态);
//把过滤后的表赋给新表
DataTable datNew = davTemp.ToTable();

取表的某列或多列

DataTable datSource;//数据源表
DataTable datNew= datSource.DefaultView.ToTable(false, new string[] { "列名", "列名" .....});

复制某行的值(前提是表结构或列数相同)

DataTable datSource;
DataTable datNew;
datSource.Rows[i].ItemArray= datNew. Rows[i].ItemArray;

调整列的位置SetOrdinal()

DataTable dat = new DataTable();
//添加三列
dat.Columns.Add("col1");
dat.Columns.Add("col2");
dat.Columns.Add("col3");
//添加一行数据
dat.Rows.Add(1,2,3);
//把第三列放到第一的位置
dat.Columns["col3"].SetOrdinal(0);