当前位置：首页 > 扩展GridView控件（八）——导出为Excel

扩展GridView控件（八）——导出为Excel

点击次数:1206  更新日期:2010-12-27
\n

GridView既强大又好用。为了让它更强大、更好用，我们来写一个继承自GridView的控件。
[源码下载]
http://files.cnblogs.com/webabcd/yycontrols.rar


\n


介绍
把GridView导出为一个Excel文件算是一个经常要用到的功能，也比较简单，我们来扩展一个GridView以实现这样的功能。


\n

控件开发
1、新建一个继承自GridView的类。
复制C#代码保存代码/// <summary>
/// 继承自GridView
/// </summary>
[ToolboxData(@"<{0}:SmartGridView runat=\'server\'></{0}:SmartGridView>")]
public class SmartGridView : GridView
{
}
2、重写OnRowCommand，以实现把GridView导出为Excel的功能
复制C#代码保存代码/// <summary>
/// OnRowCommand
/// </summary>
/// <param name=”e”></param>
protected override void OnRowCommand(GridViewCommandEventArgs e)
{
if (e.CommandName.ToLower() == “exporttoexcel”)
{
System.Web.HttpContext.Current.Response.ClearContent();
// e.CommandArgument用“;”隔开两部分，左边的部分为导出Excel的文件名称
System.Web.HttpContext.Current.Response.AddHeader(“content-disposition”,
“attachment; filename=” + e.CommandArgument.ToString().Split(‘;’)[0] + “.xls”);
System.Web.HttpContext.Current.Response.ContentType = “application/excel”;


\n

System.IO.StringWriter sw = new System.IO.StringWriter();
HtmlTextWriter htw = new HtmlTextWriter(sw);


\n

// e.CommandArgument用“;”隔开两部分，右边的部分为需要隐藏的列的索引（列索引用“,”分开）
if (e.CommandArgument.ToString().Split(‘;’).Length > 1)
{
foreach (string s in e.CommandArgument.ToString().Split(‘;’)[1].Split(‘,’))
{
int i;


\n

if (!Int32.TryParse(s, out i))
{
throw new ArgumentException(“需要隐藏的列的索引不是整数”);
}


\n

if (i > this.Columns.Count)
{
throw new ArgumentOutOfRangeException(“需要隐藏的列的索引超出范围”);
}


\n

this.Columns[i].Visible = false;
}
}


\n

// 隐藏“导出Excel”按钮
((Control) e.CommandSource).Visible = false;


\n

// 如果HeaderRow里的控件是button的话，则把它替换成文本
foreach (TableCell tc in this.HeaderRow.Cells)
{
// TableCell里的每个Control
foreach (Control c in tc.Controls)
{
// 如果控件继承自接口IButtonControl
if (c.GetType().GetInterface(“IButtonControl”) != null
&& c.GetType().GetInterface(“IButtonControl”).Equals(typeof(IButtonControl)))
{
// 如果该控件不是“导出Excel”按钮则把button转换成文本
if (!c.Equals(e.CommandSource))
{
tc.Controls.Clear();
tc.Text = ((IButtonControl) c).Text;
}
}
}
}


\n

// 将服务器控件的内容输出到所提供的 System.Web.UI.HtmlTextWriter 对象中
this.RenderControl(htw);


\n

System.Web.HttpContext.Current.Response.Write(sw.ToString());
System.Web.HttpContext.Current.Response.End();
}


\n

base.OnRowCommand(e);
}


\n

控件使用
添加这个控件到工具箱里，然后拖拽到webform上，在GridView内加一个按钮，把CommandName属性设置为“ExportToExcel”，CommandArgument属性的值用“;”做分隔符分为两部分，左边的部分为导出Excel的文件名称，右边的部分为需要隐藏的列的索引（列索引用“,”分开）
ObjData.cs
复制C#代码保存代码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.ComponentModel;


\n

/// <summary>
/// OjbData 的摘要说明
/// </summary>
public class OjbData
{
public OjbData()
{
//
// TOD 在此处添加构造函数逻辑
//
}


\n

[DataObjectMethod(DataObjectMethodType.Select, true)]
public DataTable Select()
{
DataTable dt = new DataTable();
dt.Columns.Add(“no”, typeof(string));
dt.Columns.Add(“name”, typeof(string));


\n

for (int i = 0; i < 30; i++)
{
DataRow dr = dt.NewRow();
dr[0] = “no” + i.ToString().PadLeft(2, ’0′);
dr[1] = “name” + i.ToString().PadLeft(2, ’0′);


\n

dt.Rows.Add(dr);
}


\n

return dt;
}
}
Default.aspx
复制ASPX代码保存代码<%@ Page Language=”C#” AutoEventWireup=”true” CodeFile=”Default.aspx.cs” Inherits=”_Default” %>


\n

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>
<html xmlns=”http://www.w3.org/1999/xhtml”>
<head runat=”server”>
<title>SmartGridView测试</title>
</head>
<body>
<form id=”form1″ runat=”server”>
<div>
<yyc:SmartGridView ID=”SmartGridView1″ runat=”server” AutoGenerateColumns=”False”
DataSourceID=”ObjectDataSource1″>
<Columns>
<asp:TemplateField ItemStyle-Width=”50px”>
<headertemplate>
<asp:Button id=”btnExportToExcel” runat=”server” Text=”Excel” CommandName=”ExportToExcel” CommandArgument=”ExcelFileName;5,6″ />
</headertemplate>
<itemtemplate>
<%# Container.DataItemIndex + 1 %>
</itemtemplate>
</asp:TemplateField>
<asp:BoundField DataField=”no” HeaderText=”序号” SortExpression=”no” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”name” HeaderText=”名称” SortExpression=”name” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”no” HeaderText=”序号” SortExpression=”no” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”name” HeaderText=”名称” SortExpression=”name” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”no” HeaderText=”序号” SortExpression=”no” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”name” HeaderText=”名称” SortExpression=”name” ItemStyle-Width=”100px” />
</Columns>
</yyc:SmartGridView>
<asp:ObjectDataSource ID=”ObjectDataSource1″ runat=”server” SelectMethod=”Select”
TypeName=”OjbData”></asp:ObjectDataSource>
</div>
</form>
</body>
</html><%@ Page Language=”C#” AutoEventWireup=”true” CodeFile=”Default.aspx.cs” Inherits=”_Default” %>


\n

<!DOCTYPE html PUBLIC “-//W3C//DTD XHTML 1.0 Transitional//EN” “http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd”>
<html xmlns=”http://www.w3.org/1999/xhtml”>
<head runat=”server”>
<title>SmartGridView测试</title>
</head>
<body>
<form id=”form1″ runat=”server”>
<div>
<yyc:SmartGridView ID=”SmartGridView1″ runat=”server” AutoGenerateColumns=”False”
DataSourceID=”ObjectDataSource1″>
<Columns>
<asp:TemplateField ItemStyle-Width=”50px”>
<headertemplate>
<asp:Button id=”btnExportToExcel” runat=”server” Text=”Excel” CommandName=”ExportToExcel” CommandArgument=”ExcelFileName;5,6″ />
</headertemplate>
<itemtemplate>
<%# Container.DataItemIndex + 1 %>
</itemtemplate>
</asp:TemplateField>
<asp:BoundField DataField=”no” HeaderText=”序号” SortExpression=”no” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”name” HeaderText=”名称” SortExpression=”name” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”no” HeaderText=”序号” SortExpression=”no” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”name” HeaderText=”名称” SortExpression=”name” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”no” HeaderText=”序号” SortExpression=”no” ItemStyle-Width=”100px” />
<asp:BoundField DataField=”name” HeaderText=”名称” SortExpression=”name” ItemStyle-Width=”100px” />
</Columns>
</yyc:SmartGridView>
<asp:ObjectDataSource ID=”ObjectDataSource1″ runat=”server” SelectMethod=”Select”
TypeName=”OjbData”></asp:ObjectDataSource>
</div>
</form>
</body>
</html>
注：为了防止出错要在.cs代码中加上下面这句
复制C#代码保存代码public override void VerifyRenderingInServerForm(Control control)
{


\n

}
另外，如果你的GridView中含有命令按钮的话要在.aspx页面的头部中加上下面这个属性
复制C#代码保存代码EnableEventValidation=”false”


\n

转自【webabcd-.NET】

\n