using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Text;
using System.Globalization;
using System.IO;
namespace CSPlatform.Website.Admin
{
public class ExcelHelper
{
#region Fields
string _fileName;
DataTable _dataSource;
string[] _titles = null;
string[] _fields = null;
int _maxRecords = 1000;
#endregion
#region Properties
/**/
/// <summary>
/// 限制输出到 Excel 的最大记录数。超出则抛出异常
/// </summary>
public int MaxRecords
{
set { _maxRecords = value; }
get { return _maxRecords; }
}
/**/
/// <summary>
/// 输出到浏览器的 Excel 文件名
/// </summary>
public string FileName
{
set { _fileName = value; }
get { return _fileName; }
}
#endregion
#region .ctor
/**/
/// <summary>
/// 构造函数
/// </summary>
/// <param name="titles">要输出到 Excel 的列标题的数组</param>
/// <param name="fields">要输出到 Excel 的字段名称数组</param>
/// <param name="dataSource">数据源</param>
public ExcelHelper(string[] titles, string[] fields, DataTable dataSource)
: this(titles, dataSource)
{
if (fields == null || fields.Length == 0)
throw new ArgumentNullException("fields");
if (titles.Length != fields.Length)
throw new ArgumentException("titles.Length != fields.Length", "fields");
_fields = fields;
}
/**/
/// <summary>
/// 构造函数
/// </summary>
/// <param name="titles">要输出到 Excel 的列标题的数组</param>
/// <param name="dataSource">数据源</param>
public ExcelHelper(string[] titles, DataTable dataSource)
: this(dataSource)
{
if (titles == null || titles.Length == 0)
throw new ArgumentNullException("titles");
//if (titles.Length != dataSource.Columns.Count)
// throw new ArgumentException("titles.Length != dataSource.Columns.Count", "dataSource");
_titles = titles;
}
/**/
/// <summary>
/// 构造函数
/// </summary>
/// <param name="dataSource">数据源</param>
public ExcelHelper(DataTable dataSource)
{
if (dataSource == null)
throw new ArgumentNullException("dataSource");
// maybe more checks needed here (IEnumerable, IList, IListSource, ) ???
// 很难判断，先简单的使用 DataTable
_dataSource = dataSource;
}
public ExcelHelper() { }
#endregion
#region public Methods
/**/
/// <summary>
/// 导出到 Excel 并提示下载
/// </summary>
/// <param name="dg">DataGrid</param>
public void Export(DataGrid dg)
{
if (dg == null)
throw new ArgumentNullException("dg");
if (dg.AllowPaging || dg.PageCount > 1)
throw new ArgumentException("paged DataGrid can't be exported.", "dg");
// 添加标题样式
dg.HeaderStyle.Font.Bold = true;
dg.HeaderStyle.BackColor = System.Drawing.Color.LightGray;
RenderExcel(dg);
}
/**/
/// <summary>
/// 导出到 Excel 并提示下载
/// </summary>
public void Export()
{
if (_dataSource == null)
throw new Exception("数据源尚未初始化");
if (_fields == null && _titles != null && _titles.Length != _dataSource.Columns.Count)
throw new Exception("_titles.Length != _dataSource.Columns.Count");
if (_dataSource.Rows.Count > _maxRecords)
throw new Exception("导出数据条数超过限制。请设置 MaxRecords 属性以定义导出的最多记录数。");
DataGrid dg = new DataGrid();
dg.DataSource = _dataSource;
if (_titles == null)
{
dg.AutoGenerateColumns = true;
}
else
{
dg.AutoGenerateColumns = false;
int cnt = _titles.Length;
System.Web.UI.WebControls.BoundColumn col;
if (_fields == null)
{
for (int i = 0; i < cnt; i++)
{
col = new System.Web.UI.WebControls.BoundColumn();
col.HeaderText = _titles[i];
col.DataField = _dataSource.Columns[i].ColumnName;
dg.Columns.Add(col);
}
}
else
{
for (int i = 0; i < cnt; i++)
{
col = new System.Web.UI.WebControls.BoundColumn();
col.HeaderText = _titles[i];
col.DataField = _fields[i];
dg.Columns.Add(col);
}
}
}
// 添加标题样式
dg.HeaderStyle.Font.Bold = true;
dg.HeaderStyle.BackColor = System.Drawing.Color.LightGray;
dg.ItemDataBound += new DataGridItemEventHandler(DataGridItemDataBound);
dg.DataBind();
RenderExcel(dg);
}
#endregion
#region private Methods
private void RenderExcel(Control c)
{
// 确保有一个合法的输出文件名
if (_fileName == null || _fileName == string.Empty || !(_fileName.ToLower().EndsWith(".xls")))
_fileName = GetRandomFileName();
HttpResponse response = HttpContext.Current.Response;
response.Charset = "GB2312";
response.ContentEncoding = Encoding.GetEncoding("GB2312");
response.ContentType = "application/ms-excel/msword";
response.AppendHeader("Content-Disposition", "attachment;filename=" +
HttpUtility.UrlEncode(_fileName));
CultureInfo cult = new CultureInfo("zh-CN", true);
StringWriter sw = new StringWriter(cult);
HtmlTextWriter writer = new HtmlTextWriter(sw);
writer.WriteLine("<meta http-equiv=\"Content-Type\" content=\"text/html;charset=GB2312\">");
DataGrid dg = c as DataGrid;
if (dg != null)
{
dg.RenderControl(writer);
}
c.Dispose();
response.Write(sw.ToString());
response.End();
}
/**/
/// <summary>
/// 得到一个随意的文件名
/// </summary>
/// <returns></returns>
private string GetRandomFileName()
{
Random rnd = new Random((int)(DateTime.Now.Ticks));
string s = rnd.Next(Int32.MaxValue).ToString();
return DateTime.Now.ToShortDateString() + "_" + s + ".xls";
}
private void DataGridItemDataBound(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)
{
if (e.Item.ItemType == ListItemType.Item || e.Item.ItemType == ListItemType.AlternatingItem)
{
e.Item.Attributes.Add("style", "vnd.ms-excel.numberformat:@");
//e.Item.Cells[3].Attributes.Add("style", "vnd.ms-excel.numberformat:￥#,###.00");
}
}
#endregion
}
}
