【AjaxPro实现机制浅析一】AjaxPro内部为我们做什么工作？

2022-07-15 80酷酷网 80kuku.com

　　ajax

先找个借口：好早就想分析下AjaxPro的代码实现机制了，一直苦于没时间，现在嘛总算有那么丁点了，开篇了，慢慢分析……

以一个最简单的例子开始：
点击一个客户端button，触发一个javascript函数，执行一个只有一个string参数的服务端方法，返回一个处理过的string，处理方法是将传入的string变成“Hi”+string +“！”；够简单了，为了是不希望罗嗦的代码影响简单的分析；
所有代码如下：
<% Page Language="C#" AutoEventWireup="true" CodeFile="Test.aspx.cs" Inherits="Test" %>

<!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>无标题页</title>
    <script type="text/javascript">

    function doTest()
    {
        AJAXDemo.Examples.Test.TestMethod.GetTest("AjaxPro",doTest_callback);
    }

namespace AJAXDemo.Examples.Test
{
    public class TestMethod
    {
        public TestMethod()
        {}

        [AjaxMethod]
        public string GetTest(string testText)
        {
            return "Hi," + testText + "!";
        }
    }
}
1.首先我们看AjaxPro在页面上给我们生成了什么？
Test[1]
<!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><title>
    无标题页
</title>
    <script type="text/javascript">

    function doTest()
    {
        AJAXDemo.Examples.Test.TestMethod.GetTest("AjaxPro",doTest_callback);
    }

    function doTest_callback(res) {
        alert(res.value);
    }

    </script>
</head>
<body>
    <form name="form1" method="post" action="Test.aspx" id="form1">
<div>
<input type="hidden" name="__VIEWSTATE" id="__VIEWSTATE" value="/wEPDwUJNzgzNDMwNTMzZGRFekXifzWDNb+qFWPbJumdlZh/dQ==" />
</div>

    <div>
        <input id="Button1" type="button" value="测试"/></div>
    </form>
</body>
</html>
一定要注意这几行
<script type="text/javascript" src="/AJAXDemo.2/ajaxpro/prototype.ashx"></script>
<script type="text/javascript" src="/AJAXDemo.2/ajaxpro/core.ashx"></script>
<script type="text/javascript" src="/AJAXDemo.2/ajaxpro/converter.ashx"></script>
<script type="text/javascript" src="/AJAXDemo.2/ajaxpro/AJAXDemo.Examples.Test.TestMethod,App_Code.urx4hqkg.ashx"></script>
通过使用http://localhost:3578/AJAXDemo.2/ajaxpro/prototype.ashx和http://localhost:3578/AJAXDemo.2/ajaxpro/core.ashx不难发现，其中前面两个是源代码中带的两个js文件（core.js和prototype.js）转化出来的，基本内容也跟原来的文件一样，而converter.ashx和AJAXDemo.Examples.Test.TestMethod,App_Code.urx4hqkg.ashx里面有什么呢？看下面：
AJAXDemo.Examples.Test.TestMethod,App_Code.urx4hqkg.ashx
addNamespace("AJAXDemo.Examples.Test");
AJAXDemo.Examples.Test.TestMethod_class = Class.create();
AJAXDemo.Examples.Test.TestMethod_class.prototype = (new AjaxPro.AjaxClass()).extend({
    GetTest: function(testText) {
        return this.invoke("GetTest", {"testText":testText}, this.GetTest.getArguments().slice(1));
    },
    initialize: function() {
        this.url = '/AJAXDemo.2/ajaxpro/AJAXDemo.Examples.Test.TestMethod,App_Code.un7rskvh.ashx';
    }
});
AJAXDemo.Examples.Test.TestMethod = new AJAXDemo.Examples.Test.TestMethod_class();
converter.ashx

addNamespace("Ajax.Web");

Ajax.Web.NameValueCollection = function()
{
this.__type = "System.Collections.Specialized.NameValueCollection";

    this.add = function(key, value) {
        if(this[key] == null) {
            this[key] = value;
        }
    }

    this.getKeys = function() {
        var keys = [];

        for(key in this)
            if(typeof this[key] != "function")
                keys.push(key);

        return keys;
    }

    this.getValue = function(key) {
        return this[key];
    }

    this.toJSON = function() {
        var o = this;
        o.toJSON = null;
        delete o.toJSON;
        return AjaxPro.toJSON(o);
    }
}

addNamespace("Ajax.Web");

Ajax.Web.DataTable = function(columns, rows) {

    this.__type = "System.Data.DataTable, System.Data";
    this.Columns = new Array();
    this.Rows = new Array();

    this.addColumn = function(name, type) {
        var c = new Object();
        c.Name = name;
        c.__type = type;

        this.Columns.push(c);
    }

this.toJSON = function() {
var dt = new Object();

        dt.Columns = [];
        for(var i=0; i<this.Columns.length; i++)
            dt.Columns.push([this.Columns[i].Name, this.Columns[i].__type]);

        dt.Rows = [];
        for(var i=0; i<this.Rows.length; i++) {
            var row = [];
            for(var j=0; j<this.Columns.length; j++)
                row.push(this.Rows[i][this.Columns[j].Name]);
            dt.Rows.push(row);
        }

return AjaxPro.toJSON(dt);
}

    this.addRow = function(row) {
        this.Rows.push(row);
    }

    if(columns != null) {
        for(var i=0; i<columns.length; i++) {
            this.addColumn(columns[i][0], columns[i][1]);
        }
    }

    if(rows != null) {
        for(var i=0; i<rows.length; i++) {
            var row = new Object();
            for(var c=0; c<this.Columns.length && c<rows[i].length; c++) {
                row[this.Columns[c].Name] = rows[i][c];
            }
            this.addRow(row);
        }
    }
}

addNamespace("Ajax.Web");

Ajax.Web.DataSet = function(tables) {
this.__type = "System.Data.DataSet, System.Data";
this.Tables = new Array();

    this.addTable = function(table) {
        this.Tables.push(table);
    }

    if(tables != null) {
        for(var i=0; i<tables.length; i++) {
            this.addTable(tables[i]);
        }
    }
}

function Person(id) {
    this.FirstName = "";
    this.FamilyName = "";
    this.Age = 0;
    this.ID = id;
    this.__type = 'AJAXDemo.Examples.Classes.Person, App_Code.un7rskvh, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null';
}

Person.prototype.get_FullName = function() {
return this.FirstName + " " + this.FamilyName;
}

Person.prototype.toJSON = function() {
var o = new Object();

    o.firstName = this.FirstName;
    o.familyName = this.FamilyName;
    o.age = this.Age;
    o.id = this.ID;

return AjaxPro.toJSON(o);
}

Person.prototype.save = function() {
return Person.save(this);
}

Person.save = function(p) {
var ps = new PersonSaver();
return ps.savePerson(p); // synchronous call
}

正因为是有了上面四个ashx文件我们的
function doTest()
{
AJAXDemo.Examples.Test.TestMethod.GetTest("AjaxPro",doTest_callback);
}
才得以异步执行，这些ashx文件又是怎么生成到页面上的，那得归功于web.config的相关配置和下面这句代码：
Utility.RegisterTypeForAjax(typeof(AJAXDemo.Examples.Test.TestMethod));

至于Utility.RegisterTypeForAjax方法产生的一序列动作我将在后文中继续说明，有兴趣的可以自己跟踪下这些代码的执行。