新瓶旧酒ASP.NET AJAX(6) - 客户端脚本编程

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新瓶旧酒ASP.NET AJAX(6) - 客户端脚本编程（Sys.WebForms命名空间下的类Sys.Serialization命名空间下的类）

作者：webabcd


介绍
Sys.WebForms命名空间下的类都是与局部刷新相关的类。PageRequestManager类，其中有5个事件：initializeRequest事件、beginRequest事件、endRequest事件、pageLoading事件和pageLoaded事件。与这5个事件相关的还有5个事件参数类：InitializeRequestEventArgs类、BeginRequestEventArgs类、EndRequestEventArgs类、PageLoadingEventArgs类和PageLoadedEventArgs类。Sys.Serialization命名空间下只有一个类：Sys.Serialization.JavaScriptSerializer类。它用于在ECMAScript(JavaScript)对象与JSON格式数据之间进行转换。


1、PageRequestManager Class
    ・initializeRequest Event - 异步回发的初始化时触发
    ・beginRequest Event - 异步回发开始前触发
    ・endRequest Event - 异步回发完成后触发
    ・pageLoading Event - 异步回发完成后页面加载开始前触发
    ・pageLoaded Event - 异步回发完成后页面加载完成后触发
    ・Sys.WebForms.PageRequestManager.getInstance(); - 返回页面的PageRequestManager类的实例
    ・Sys.WebForms.PageRequestManager.getInstance().abortPostBack(); - 终止所有异步回发
    ・isInAsyncPostBack属性 - 是否正在异步回发过程中

2、InitializeRequestEventArgs Class
    ・postBackElement属性 - 产生回发事件的元素
    ・InitializeRequestEventArgs继承自Sys.CancelEventArgs，所以具有cancel属性 - 是否取消回发

3、BeginRequestEventArgs Class
    ・postBackElement属性 - 产生回发事件的元素

4、EndRequestEventArgs Class
    ・error属性 - Error对象
    ・errorHandled属性 - 异常是否已经被处理
    ・response属性 - Sys.Net.WebRequestExecutor对象
    ・dataItems属性 - 服务端注册的DataItem

5、PageLoadingEventArgs Class
    ・panelsUpdating属性 - 准备更新的UpdatePanel数组（div元素）
    ・dataItems属性 - 服务端注册的DataItem

6、PageRequestManager Class
    ・panelsUpdated属性 - 更新完毕的UpdatePanel数组（div元素）
    ・dataItems属性 - 服务端注册的DataItem

7、Sys.Serialization.JavaScriptSerializer Class
    ・serialize方法 - 序列化（参数：ECMAScript(JavaScript)对象；返回值：JSON字符串）
    ・deserialize方法 - 反序列化（参数：JSON字符串；返回值ECMAScript(JavaScript)对象：）

8、其它请查看官方文档


示例
InitializeRequest.aspx

<%@ Page Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="InitializeRequest.aspx.cs"
        Inherits="ClientScripting_SysWebForms_InitializeRequest" Title="InitializeRequest" %>

<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">

        <script runat="Server">
                protected void Button1_Click(object sender, EventArgs e)
                {
                        System.Threading.Thread.Sleep(3000);
                }
        </script>

        <asp:UpdateProgress ID="UpdateProgress1" runat="server" DisplayAfter="0" DynamicLayout="false">
                <ProgressTemplate>
                        Loading
                </ProgressTemplate>
        </asp:UpdateProgress>
        <asp:UpdatePanel ID="UpdatePanel1" runat="server">
                <ContentTemplate>
                        <%= DateTime.Now %>
                        <br />
                        <asp:Button ID="Button1" runat="server" Text="Button" OnClick="Button1_Click" />
                          
                        <asp:Button ID="Button2" runat="server" Text="cancel属性测试" OnClick="Button1_Click" />
                </ContentTemplate>
        </asp:UpdatePanel>
        <p>
                <textarea id="TraceConsole" style="width: 500px; height: 300px;"></textarea>
        </p>

        <script type="text/javascript" language="javascript">
        
                Sys.WebForms.PageRequestManager.getInstance().add_initializeRequest(initializeRequestHandler);
                
                function initializeRequestHandler(sender, e)
                {
                        // postBackElement - 产生回发事件的元素
                        if (e.get_postBackElement().id == "<%= Button2.ClientID %>")
                        {
                                // InitializeRequestEventArgs继承自Sys.CancelEventArgs    
                                // 取消回发
                                e.set_cancel(true);
                        }
                        else
                        {
                                // 获得页面的PageRequestManager类的实例
                                var prm = Sys.WebForms.PageRequestManager.getInstance();
                        
                                Sys.Debug.trace(e.get_postBackElement().id);
                                
                                // Sys.WebForms.PageRequestManager的isInAsyncPostBack属性 - 是否正在异步回发过程中
                                Sys.Debug.trace(prm.get_isInAsyncPostBack());
                        }
                }
        </script>

</asp:Content>

 

 

运行结果
1、单击“Button”按钮
ctl00_ContentPlaceHolder1_Button1
false

2、在Loading的过程中再次单击“Button”按钮
ctl00_ContentPlaceHolder1_Button1
true

3、单击“cancel属性测试”按钮
没有反应


BeginRequestAndEndRequest.aspx
注：在ScriptManager的OnAsyncPostBackError事件中输入代码：ScriptManager1.AsyncPostBackErrorMessage = e.Exception.Message + "（母版页的ScriptManager格式化错误信息）";

<%@ Page Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="BeginRequestAndEndRequest.aspx.cs"
        Inherits="ClientScripting_SysWebForms_BeginRequestAndEndRequest" Title="BeginRequest和EndRequest" %>

<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">

        <script runat="Server">
                protected void Button1_Click(object sender, EventArgs e)
                {
                        int i = Int32.Parse("abc");
                }

                protected void Button2_Click(object sender, EventArgs e)
                {
                        ScriptManager.GetCurrent(this).RegisterDataItem(this.UpdatePanel1, "webabcd");
                }
        </script>

        <asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="Server">
                <ContentTemplate>
                        <%= DateTime.Now.ToString() %>
                        <br />
                        <asp:Button ID="Button1" runat="server" Text="触发异常" OnClick="Button1_Click" />
                          
                        <asp:Button ID="Button2" runat="server" Text="RegisterDataItem测试" OnClick="Button2_Click" />
                </ContentTemplate>
        </asp:UpdatePanel>

        <p>
                <textarea id="TraceConsole" style="width: 500px; height: 100px;"></textarea>
        </p>

        <script language="javascript" type="text/javascript">

                Sys.WebForms.PageRequestManager.getInstance().add_beginRequest(beginRequestHandler);
                Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endRequestHandler);
                Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endRequestHandler2);

                function beginRequestHandler(sender, e)
                {
                        // postBackElement - 产生回发事件的元素
                        alert(e.get_postBackElement().id);                        
                }
                                
                function endRequestHandler(sender, e)
                {
                        // response - Sys.Net.WebRequestExecutor对象
                        Sys.Debug.trace("状态代码：" + e.get_response().get_statusCode());
        
                        if (e.get_error())
                        {
                                // errorHandled - 异常是否已经被处理
                                e.set_errorHandled(true);
                                // error - Error对象
                                Sys.Debug.trace("出错了！错误信息：" + e.get_error().message);
                        }
                }
                
                function endRequestHandler2(sender, e)
                {
                        var upId = "<%= this.UpdatePanel1.ClientID %>";
                        
                        // dataItems - 服务端注册的DataItem
                        if (typeof(e.get_dataItems()[upId]) != 'undefined')
                        {
                                Sys.Debug.trace("注册的数据项为：" + e.get_dataItems()[upId]);
                        }
                }

        </script>

</asp:Content>

 

 

运行结果
1、单击“触发异常”按钮
弹出框，信息：ct100_ContentPlaceHolder1_Button1
状态代码：200
出错了！错误信息：输入字符串的格式不正确。（母版页的ScriptManager格式化错误信息）

2、单击“RegisterDataItem测试”按钮
弹出框，信息：ct100_ContentPlaceHolder1_Button2
状态代码：200
注册的数据项为：webabcd


Sample.aspx

<%@ Page Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true" CodeFile="Sample.aspx.cs"
        Inherits="ClientScripting_SysSerialization_Sample" Title="Sys.Serialization Sample" %>

<asp:Content ID="Content1" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">

        <script runat="Server">
                protected void Button1_Click(object sender, EventArgs e)
                {
                        // 创建一个Person对象
                        Person person = new Person();
                        person.Name = "webabcd";
                        person.Age = 27;

                        // 序列化上面创建的Person对象，使其成为一个JSON字符串
                        System.Web.Script.Serialization.JavaScriptSerializer jss = new System.Web.Script.Serialization.JavaScriptSerializer();
                        string s = jss.Serialize(person);
                        
                        // 注册DataItem
                        ScriptManager.GetCurrent(this).RegisterDataItem(this.UpdatePanel1, s);
                }

                /// <summary>
                /// Person类
                /// </summary>
                public class Person
                {
                        private string _name;
                        /// <summary>
                        /// 姓名
                        /// </summary>
                        public string Name
                        {
                                get { return _name; }
                                set { _name = value; }
                        }

                        private int _age;
                        /// <summary>
                        /// 年龄
                        /// </summary>
                        public int Age
                        {
                                get { return _age; }
                                set { _age = value; }
                        }

                }
        </script>

        <asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Conditional" runat="Server">
                <ContentTemplate>
                        <%= DateTime.Now.ToString()%>
                        <br />
                        <asp:Button ID="Button1" runat="server" Text="Sys.Serialization" OnClick="Button1_Click" />
                </ContentTemplate>
        </asp:UpdatePanel>
        <p>
                <textarea id="TraceConsole" style="width: 500px; height: 100px;"></textarea>
        </p>

        <script language="javascript" type="text/javascript">

                Sys.WebForms.PageRequestManager.getInstance().add_endRequest(endRequestHandler);
                
                function endRequestHandler(sender, e)
                {
                        var upId = "<%= this.UpdatePanel1.ClientID %>";
                        
                        // 获得服务端注册的DataItem，它是一个JSON字符串
                        var jsonStringServer = e.get_dataItems()[upId];
                        
                        // 反序列化这个JSON字符串，使其成为一个JSON对象
                        var jsonObject = Sys.Serialization.JavaScriptSerializer.deserialize(jsonStringServer)

                        // 序列化这个JOSN对象，使其成为一个JSON字符串
                        var jsonStringClient = Sys.Serialization.JavaScriptSerializer.serialize(jsonObject);
                        
                        Sys.Debug.trace(jsonStringClient);
                        
                        Sys.Debug.trace(jsonObject.Name + " " + jsonObject.Age);
                        
                        Sys.Debug.trace(Sys.Serialization.JavaScriptSerializer.serialize(jsonObject));
                }

        </script>

</asp:Content>

 

 

运行结果
单击“Sys.Serialization”按钮
{"Name":"webabcd","Age":27}
webabcd 27
{"Name":"webabcd","Age":27}


OK
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