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原文請(qǐng)見Leon.Zhou的：http://pfzhou.cnblogs.com/archive/2006/03/31/363342.html
下載了示例代碼，并轉(zhuǎn)換成VB了，AJAX功能測(cè)試成功。但遇到些小問題：
Demo1很正常。
Demo2按Leon原來的寫法testAJAX.aspx.vb中Line
22不成功。所以我直接在IDE環(huán)境中，修改button3的OnClientClick屬性，見testAJAX.asp的Line
52。測(cè)試成功。
Demo3按原來的加入客戶端屬性無法成功，在testAJAX.aspx.vb中第20行并未起作用。不知道是什么原因。
因此我只有加上一個(gè)button3來引發(fā)客戶端事件。
這是個(gè)很好的例子，值得學(xué)習(xí)，詳細(xì)原理說明請(qǐng)見作者的原文。測(cè)試時(shí)，請(qǐng)?jiān)谀?xiàng)目的web.config中添加<add
name="NorthWind" connectionString="...相應(yīng)的數(shù)據(jù)庫連接串...">
testAJAX.aspx
1<%@ Page Language="VB" AutoEventWireup="false"
CodeFile="testAJAX.aspx.vb" Inherits="testAJAX" %>
2
3<!DOCTYPE
html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www./TR/xhtml1/DTD/xhtml1-transitional.dtd">
4
5<html
xmlns="http://www./1999/xhtml"
>
6<head id="Head1" runat="server">
7 <title>ASP.NET
2.0 頁面提交無刷新演示</title>
8 <script type="text/javascript" language
="javascript">
9 Function CallServer1()function
CallServer1(inputcontrol, context)
10 {
11
context.innerHTML = "<IMG SRC=images/pie.gif />Loading";
12
arg = ServerMethod1| + inputcontrol.value;
13 <%=
ClientScript.GetCallbackEventReference(Me, "arg", "ReceiveServerData1",
"context")%>;
14 }
15
16 Function
ReceiveServerData1()function ReceiveServerData1(result, context)
17
{
18 context.innerHTML = context.id + "：" + result;
19
}
20
21 Function CallServer2()function
CallServer2(obj)
22 {
23 context =
gridspan;
24 context.innerHTML = "<IMG SRC=images/pie.gif
/>數(shù)據(jù)加載中";
25 arg = "ServerMethod2|" +
obj.value;
26 <%= ClientScript.GetCallbackEventReference(Me,
"arg", "ReceiveServerData2", "context")%>;
27 }
28
29 Function ReceiveServerData2()function ReceiveServerData2(result,
context)
30 {
31 context.innerHTML =
result;
32 }
33
34
</script>
35</head>
36<body>
37 <form
id="form1" runat="server">
38 <div>
39
<h1>Demo1:html按鈕提交數(shù)據(jù)</h1><br />
40 <asp:TextBox
ID="TextBox1" runat="server"></asp:TextBox>
41 <input
id="Button1" type="button" value="提交到Label1" onclick="CallServer1(TextBox1,
Label1)"/>
42 <input id="Button2" type="button"
value="提交到Label2" onclick="CallServer1(TextBox1, Label2)"/>
43
<br />
44 <asp:Label ID="Label1" runat="server"
Text="Label1:"></asp:Label>
45 <br />
46
<asp:Label ID="Label2" runat="server"
Text="Label2:"></asp:Label>
47 </div>
48 <hr
/>
49 <div>
50
<h1>Demo2:服務(wù)器按鈕提交數(shù)據(jù)</h1><br />
51 <asp:TextBox
ID="TextBox2" runat="server"></asp:TextBox>
52 <asp:Button
ID="Button3" runat="server" Text="Button" OnClientClick="CallServer1(TextBox2,
Label3);return false;" /><br />
53 <asp:Label ID="Label3"
runat="server" Text="Label3:"></asp:Label></div>
54
<hr />
55 <div>
56
<h1>Demo3:下拉列表框和gridview綁定數(shù)據(jù)</h1><br />
57
<asp:SqlDataSource ID="SqlDataSource1" runat="server"
ConnectionString="<%$ connectionStrings:NorthWind %>"
58
SelectCommand="select distinct(country) from
customers"></asp:SqlDataSource>
59 <asp:SqlDataSource
ID="SqlDataSource2" runat="server" ConnectionString="<%$
connectionStrings:NorthWind %>"
60 SelectCommand="select
customerid, companyname, country from customers where country=@Country">
61
<SelectParameters>
62 <asp:ControlParameter
Name="Country" ControlID="DropDownList1" PropertyName="SelectedValue"
/>
63 </SelectParameters>
64
</asp:SqlDataSource>
65 <div>
66
<asp:DropDownList ID="DropDownList1" runat="server" Width="239px"
67 DataSourceID="SqlDataSource1" DataTextField="Country"
DataValueField="Country">
68
</asp:DropDownList>
69 <input id="Button4" type="button"
value="刷新" onclick="CallServer2(DropDownList1)"/>
70
</div>
71 <br />
72 <span
id="gridspan">
73 <asp:GridView ID="GridView1"
runat="server" DataSourceID="SqlDataSource2" CellPadding="4" ForeColor="#333333"
GridLines="None">
74 <FooterStyle BackColor="#990000"
Font-Bold="True" ForeColor="White" />
75 <RowStyle
BackColor="#FFFBD6" ForeColor="#333333" />
76
<SelectedRowStyle BackColor="#FFCC66" Font-Bold="True" ForeColor="Navy"
/>
77 <PagerStyle BackColor="#FFCC66"
ForeColor="#333333" HorizontalAlign="Center" />
78
<HeaderStyle BackColor="#990000" Font-Bold="True" ForeColor="White"
/>
79 <AlternatingRowStyle BackColor="White"
/>
80 </asp:GridView>
81 </span>
82
</div>
83
</form>
84</body>
85</html>
86
testAJAX.aspx.vb
1
2Imports
System
3Imports System.Data
4Imports System.Configuration
5Imports
System.Web
6Imports System.Web.Security
7Imports
System.Web.UI
8Imports System.Web.UI.WebControls
9Imports
System.Web.UI.WebControls.WebParts
10Imports
System.Web.UI.HtmlControls
11Imports System.IO
12Imports
System.Globalization
13
14Partial Public Class testAJAXClass
testAJAX
15 Inherits System.Web.UI.Page
16 Implements
ICallbackEventHandler
17 Protected Sub Page_Load()Sub Page_Load(ByVal
sender As Object, ByVal e As EventArgs)
18 注冊(cè)客戶端事件處理方法
19
似乎這句并沒起作用，因此我別外加了一個(gè)button4來引發(fā)客戶端事件 by AndyDavis
20
DropDownList1.Attributes.Add("onchange", "CallServer2(this)")
21
Button3的客戶端事件可以直接在IDE中OnClientClick屬性中設(shè)置，不需要在這里添加 by AndyDavis
22
Button3.Attributes.Add("onclick", "CallServer1(TextBox2, Label3);return
false;")
23 End Sub
24
25 Private serverReturn As
String
26
27 Public Function GetCallbackResult()Function
GetCallbackResult() As String Implements
ICallbackEventHandler.GetCallbackResult
28 為便于查看加載效果，添加延時(shí)
29
System.Threading.Thread.Sleep(2000)
30
31 Dim parts() As String =
serverReturn.Split("|"c)
32
根據(jù)傳遞的方法名進(jìn)行調(diào)用，并傳遞相應(yīng)的參數(shù)，目前只支持一個(gè)參數(shù)
33 Return
CStr([GetType]().GetMethod(parts(0)).Invoke(Me, New Object()
{parts(1)}))
34 End Function
35
36
37 Public Sub
RaiseCallbackEvent()Sub RaiseCallbackEvent(ByVal eventArgument As String)
Implements ICallbackEventHandler.RaiseCallbackEvent
38 serverReturn =
eventArgument
39 End Sub
40
41
根據(jù)從客戶端傳來的英文國家名或縮寫，翻譯成相應(yīng)的中文國家名
42 Public Function ServerMethod1()Function
ServerMethod1(ByVal arg As String) As String
43 Dim s As String =
""
44 Select Case arg.ToLower()
45 Case
"cn"
46 Case "china"
47 s =
"中國"
48 Exit Select
49 Case
"us"
50 s = "美國"
51 Exit
Select
52 Case Else
53 s =
"未知國家"
54 Exit Select
55 End Select
56
Return s
57 End Function
58
59
根據(jù)從客戶端傳來的值，對(duì)GridView的內(nèi)容進(jìn)行更新，并將更新后的GridView的html返回
60 Public Function
ServerMethod2()Function ServerMethod2(ByVal arg As String) As
String
61 DropDownList1.SelectedValue = arg
62
GridView1.DataBind()
63
64 Return RenderControl(GridView1)
65
End Function
66
67 Private Overloads Function RenderControl()Function
RenderControl(ByVal control As Control) As String
68 Dim writer1 As
StringWriter = New StringWriter(CultureInfo.InvariantCulture)
69 Dim
writer2 As HtmlTextWriter = New HtmlTextWriter(writer1)
70
71
control.RenderControl(writer2)
72 writer2.Flush()
73
writer2.Close()
74
75 Return writer1.ToString()
76 End
Function
77End Class
78
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