将ASP.Net 2.0下的GridView导出为Excel.
简介：
在本文中我们将具体介绍如何将ASP.Net 2.0下的GridView导出为Excel.
本文的焦点是Gridview导为Excel功能和它的数据绑定只出口示范功能.
本文代码可以用来导出为Excel的功能但不局限于这个部分，还可以在很多项目中使用。
Step 1: Setup your web page with the Gridview
这里我假定你满足：在一个页面中有个名为GridView1的GridView。在GridView中我们绑定了一个名为ContactPhone的SQL数据库。接下来的代码就是如何将GridView导出为Excel并且不依赖于具体的数据绑定还具有场景自改变能力。
ContactPhone Table Structure:
| Column Name |
Type |
| ContactID |
Int (Identity) |
| FName |
Varchar(50) |
| LName |
Varchar(50) |
| ContactPhone |
Varchar(20) |
Step: The Actual Export
这段代码是直接输出为Excel的，你也可以改变content-disposition和ContentType以输出不同的类型。
1
string
attachment
=
"
attachment; filename=Contacts.xls
"
;
2
3Response.ClearContent();
4
5Response.AddHeader(
"
content-disposition
"
, attachment);
6
7Response.ContentType
=
"
application/ms-excel
"
;
8
9StringWriter sw
=
new
StringWriter();
10
11HtmlTextWriter htw
=
new
HtmlTextWriter(sw);
12
13GridView1.RenderControl(htw);
14
15Response.Write(sw.ToString());
16
17Response.End();
18
19
string
attachment
=
"
attachment; filename=Contacts.xls
"
;2
3
Response.ClearContent();4
5
Response.AddHeader(
"
content-disposition
"
, attachment);6
7
Response.ContentType
=
"
application/ms-excel
"
;8
9
StringWriter sw
=
new
StringWriter();10
11
HtmlTextWriter htw
=
new
HtmlTextWriter(sw);12
13
GridView1.RenderControl(htw);14
15
Response.Write(sw.ToString());16
17
Response.End(); 18
19
如果你运行以上代码，将返回一个HttpException：
'GridView1'是一个类型为'GridView'的控件，必须为其添加一个runat=server标记.
为避免这个错误，我们添加以下代码：
1
public
override
void
VerifyRenderingInServerForm(Control control)
2
3
{
4
5
}
6
public
override
void
VerifyRenderingInServerForm(Control control)2
3
{4
5
}
6
Step : Convert the contents
如果GridView中有其它控件，比如Checkboxes，Dropdownlists，我们需要将它转换为其相关的值，以下递归就用于导出Excel前的准备工作,将各类控件转换为其相关值.
1
private
void
PrepareGridViewForExport(Control gv)
2
3
{
4
5 LinkButton lb = new LinkButton();
6
7 Literal l = new Literal();
8
9 string name = String.Empty;
10
11 for (int i = 0; i < gv.Controls.Count; i++)
12
13
{
14
15 if (gv.Controls[i].GetType() == typeof(LinkButton))
16
17 {
18
19 l.Text = (gv.Controls[i] as LinkButton).Text;
20
21 gv.Controls.Remove(gv.Controls[i]);
22
23 gv.Controls.AddAt(i, l);
24
25
}
26
27 else if (gv.Controls[i].GetType() == typeof(DropDownList))
28
29 {
30
31 l.Text = (gv.Controls[i] as DropDownList).SelectedItem.Text;
32
33 gv.Controls.Remove(gv.Controls[i]);
34
35 gv.Controls.AddAt(i, l);
36
37 }
38
39 else if (gv.Controls[i].GetType() == typeof(CheckBox))
40
41 {
42
43 l.Text = (gv.Controls[i] as CheckBox).Checked? "True" : "False";
44
45 gv.Controls.Remove(gv.Controls[i]);
46
47 gv.Controls.AddAt(i, l);
48
49 }
50
51 if (gv.Controls[i].HasControls())
52
53 {
54
55 PrepareGridViewForExport(gv.Controls[i]);
56
57 }
58
59}
60
61
private
void
PrepareGridViewForExport(Control gv)2
3
{4
5
LinkButton lb = new LinkButton();6
7
Literal l = new Literal();8
9
string name = String.Empty;10
11
for (int i = 0; i < gv.Controls.Count; i++)12
13
{14
15
if (gv.Controls[i].GetType() == typeof(LinkButton))16
17
{18
19
l.Text = (gv.Controls[i] as LinkButton).Text;20
21
gv.Controls.Remove(gv.Controls[i]);22
23
gv.Controls.AddAt(i, l);24
25
}26
27
else if (gv.Controls[i].GetType() == typeof(DropDownList))28
29
{30
31
l.Text = (gv.Controls[i] as DropDownList).SelectedItem.Text;32
33
gv.Controls.Remove(gv.Controls[i]);34
35
gv.Controls.AddAt(i, l);36
37
}38
39
else if (gv.Controls[i].GetType() == typeof(CheckBox))40
41
{42
43
l.Text = (gv.Controls[i] as CheckBox).Checked? "True" : "False";44
45
gv.Controls.Remove(gv.Controls[i]);46
47
gv.Controls.AddAt(i, l);48
49
}50
51
if (gv.Controls[i].HasControls())52
53
{54
55
PrepareGridViewForExport(gv.Controls[i]);56
57
}58
59
}60
61
Code Listing:
Image: Page Design
Image : Sample in action
Image: Export to Excel button is clicked
Image: GridView contents exported to Excel
ExcelExport.aspx
1
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="ExportExcel.aspx.cs" Inherits="DeleteConfirm" %>2
3
4
5
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">6
7
8
9
<html xmlns="http://www.w3.org/1999/xhtml" >10
11
<head runat="server">12
13
<title>Contacts Listing</title>14
15
</head>16
17
<body>18
19
<form id="form1" runat="server">20
21
<div>22
23
<strong><span style="font-size: small; font-family: Arial; text-decoration: underline">24
25
Contacts Listing 26
27
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="Export To Excel" /></span></strong><br />28
29
<br />30
31
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="ContactID"32
33
DataSourceID="SqlDataSource1" EmptyDataText="There are no data records to display." style="font-size: small; font-family: Arial" BackColor="White" BorderColor="#DEDFDE" BorderStyle="None" BorderWidth="1px" CellPadding="4" ForeColor="Black" GridLines="Vertical">34
35
<Columns>36
37
<asp:BoundField DataField="ContactID" HeaderText="ContactID" ReadOnly="True" SortExpression="ContactID" Visible="False" />38
39
<asp:BoundField DataField="FName" HeaderText="First Name" SortExpression="FName" />40
41
<asp:BoundField DataField="LName" HeaderText="Last Name" SortExpression="LName" />42
43
<asp:BoundField DataField="ContactPhone" HeaderText="Phone" SortExpression="ContactPhone" />44
45
<asp:TemplateField HeaderText="Favorites">46
47
<ItemTemplate>48
49
50
51
<asp:CheckBox ID="CheckBox1" runat="server" />52
53
</ItemTemplate></asp:TemplateField>54
55
</Columns>56
57
<FooterStyle BackColor="#CCCC99" />58
59
<RowStyle BackColor="#F7F7DE" />60
61
<SelectedRowStyle BackColor="#CE5D5A" Font-Bold="True" ForeColor="White" />62
63
<PagerStyle BackColor="#F7F7DE" ForeColor="Black" HorizontalAlign="Right" />64
65
<HeaderStyle BackColor="#6B696B" Font-Bold="True" ForeColor="White" />66
67
<AlternatingRowStyle BackColor="White" />68
69
</asp:GridView>70
71
72
73
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ContactsConnectionString1 %>"74
75
DeleteCommand="DELETE FROM [ContactPhone] WHERE [ContactID] = @ContactID" InsertCommand="INSERT INTO [ContactPhone] ([FName], [LName], [ContactPhone]) VALUES (@FName, @LName, @ContactPhone)"76
77
ProviderName="<%$ ConnectionStrings:ContactsConnectionString1.ProviderName %>"78
79
SelectCommand="SELECT [ContactID], [FName], [LName], [ContactPhone] FROM [ContactPhone]"80
81
UpdateCommand="UPDATE [ContactPhone] SET [FName] = @FName, [LName] = @LName, [ContactPhone] = @ContactPhone WHERE [ContactID] = @ContactID">82
83
<InsertParameters>84
85
<asp:Parameter Name="FName" Type="String" />86
87
<asp:Parameter Name="LName" Type="String" />88
89
<asp:Parameter Name="ContactPhone" Type="String" />90
91
</InsertParameters>92
93
<UpdateParameters>94
95
<asp:Parameter Name="FName" Type="String" />96
97
<asp:Parameter Name="LName" Type="String" />98
99
<asp:Parameter Name="ContactPhone" Type="String" />100
101
<asp:Parameter Name="ContactID" Type="Int32" />102
103
</UpdateParameters>104
105
<DeleteParameters>106
107
<asp:Parameter Name="ContactID" Type="Int32" />108
109
</DeleteParameters>110
111
</asp:SqlDataSource>112
113
114
115
<br />116
117
</div>118
119
</form>120
121
</body>122
123
</html>124
125
ExcelExport.aspx.cs
1
using System;2
3
using System.Data;4
5
using System.Configuration;6
7
using System.Collections;8
9
using System.Web;10
11
using System.Web.Security;12
13
using System.Web.UI;14
15
using System.Web.UI.WebControls;16
17
using System.Web.UI.WebControls.WebParts;18
19
using System.Web.UI.HtmlControls;20
21
using System.Text;22
23
using System.IO;24
25
26
27
public partial class DeleteConfirm : System.Web.UI.Page28
29
{30
31
32
33
protected void Page_Load(object sender, EventArgs e)34
35
{36
37
}38
39
40
41
protected void Button1_Click(object sender, EventArgs e)42
43
{44
45
//Export the GridView to Excel46
47
PrepareGridViewForExport(GridView1);48
49
ExportGridView();50
51
}52
53
54
55
private void ExportGridView()56
57
{58
59
string attachment = "attachment; filename=Contacts.xls";60
61
Response.ClearContent();62
63
Response.AddHeader("content-disposition", attachment);64
65
Response.ContentType = "application/ms-excel";66
67
StringWriter sw = new StringWriter();68
69
HtmlTextWriter htw = new HtmlTextWriter(sw);70
71
GridView1.RenderControl(htw);72
73
Response.Write(sw.ToString());74
75
Response.End();76
77
}78
79
80
81
public override void VerifyRenderingInServerForm(Control control)82
83
{84
85
}86
87
88
89
private void PrepareGridViewForExport(Control gv)90
91
{92
93
LinkButton lb = new LinkButton();94
95
Literal l = new Literal();96
97
string name = String.Empty;98
99
for (int i = 0; i < gv.Controls.Count; i++)100
101
{102
103
if (gv.Controls[i].GetType() == typeof(LinkButton))104
105
{106
107
l.Text = (gv.Controls[i] as LinkButton).Text;108
109
gv.Controls.Remove(gv.Controls[i]);110
111
gv.Controls.AddAt(i, l);112
113
}114
115
else if (gv.Controls[i].GetType() == typeof(DropDownList))116
117
{118
119
l.Text = (gv.Controls[i] as DropDownList).SelectedItem.Text;120
121
gv.Controls.Remove(gv.Controls[i]);122
123
gv.Controls.AddAt(i, l);124
125
}126
127
else if (gv.Controls[i].GetType() == typeof(CheckBox))128
129
{130
131
l.Text = (gv.Controls[i] as CheckBox).Checked ? "True" : "False";132
133
gv.Controls.Remove(gv.Controls[i]);134
135
gv.Controls.AddAt(i, l);136
137
}138
139
if (gv.Controls[i].HasControls())140
141
{142
143
PrepareGridViewForExport(gv.Controls[i]);144
145
}146
147
}148
149
}150
151
}152
153
Implementation Options:
通常情况,在输出函数中开发人员都会面临一个错误,典型的就是"RegisterForEventValidation can only be called during Render();"
访问者通常会在评论中提出一些好的建议.我特别要强调的是开发者需要重写VerifyRenderingInServerForm方法,该方法描述如下:
- Step 1:实现导出功能的上述功能.
- Step 2:重写一个VerifyRenderingInServerForm的空方法.
- Step 3:修改ExportGridView函数,在绿色高亮代码部创建HtmlForm【原句为:The code highlighted in green creates and HtmlForm on the fly,在翻译HtmlForm on the fly时遇到了一些困难,故on the fly未翻译,请各位高手指教】,在导出girdview之前，添加gridview 到新的form并且render它（取代原来的render实现）
1
private
void
ExportGridView()
2
3
{
4
5 string attachment = "attachment; filename=Contacts.xls";
6
7 Response.ClearContent();
8
9 Response.AddHeader("content-disposition", attachment);
10
11 Response.ContentType = "application/ms-excel";
12
13 StringWriter sw = new StringWriter();
14
15 HtmlTextWriter htw = new HtmlTextWriter(sw);
16
17
18
19 // Create a form to contain the grid
20
21 HtmlForm frm = new HtmlForm();
22
23 GridView1.Parent.Controls.Add(frm);
24
25 frm.Attributes["runat"] = "server";
26
27 frm.Controls.Add(GridView1);
28
29
30
31 frm.RenderControl(htw);
32
33 //GridView1.RenderControl(htw);
34
35 Response.Write(sw.ToString());
36
37 Response.End();
38
39}
40
41
private
void
ExportGridView()2
3
{4
5
string attachment = "attachment; filename=Contacts.xls";6
7
Response.ClearContent();8
9
Response.AddHeader("content-disposition", attachment);10
11
Response.ContentType = "application/ms-excel";12
13
StringWriter sw = new StringWriter();14
15
HtmlTextWriter htw = new HtmlTextWriter(sw);16
17
18
19
// Create a form to contain the grid20
21
HtmlForm frm = new HtmlForm();22
23
GridView1.Parent.Controls.Add(frm);24
25
frm.Attributes["runat"] = "server";26
27
frm.Controls.Add(GridView1);28
29
30
31
frm.RenderControl(htw);32
33
//GridView1.RenderControl(htw);34
35
Response.Write(sw.ToString());36
37
Response.End();38
39
}
40
41
这样实施有个优势,就是可将其设置为复用代码类库,不用每次去复写基类的方法.
Note to readers:
Thank you for your comments and feedback! Happy coding!!!
ASP.Net 2.0: Export GridView to Excel - Part II
该文中将会在导出Excel 时GridView引入Hyperlink列,以至于需要使用更多的反射来重新设计原来的逻辑.