
在上一篇Blog文章中,讲述了JavaScript与Silverlight托管代码相互调用的一些方法。实际上,HTMLWindow的GetProperty方法和Invoke/InvokeSelf方法的返回值是Object类型的,代表 DOM对象或者JavaScript对象(HTMLdocument、HTMLElement、HTMLObject、ScriptObject)的返回值自动作为最接近的类型进行返回,但是,程序开发人员仍然需要明确地将该对象转换成相应的类型。所有的数字,由于跨浏览器的原因,都作为Double类型返回,如果需要Int32类型,则执行Convert.ToInt32()方法即可。
在现代的Web应用中,JsON的使用越来越频繁。Silverlight 2中要调用JavaScript中的JsON对象,首先在托管代码中声明一个类,类的属性与JsON对象的属性一致(不必完全一致),然后在托管代码中将ScriptObject对象转换成声明的这个类型即可。
下面是一个完整的例子:
Page.xaml:
< UserControl x:Class ="SilverlightApplication1.Page"xmlns ="http://schemas.microsoft.com/clIEnt/2007"
xmlns:x ="http://schemas.microsoft.com/winfx/2006/xaml"
WIDth ="600" Height ="480" >
< GrID x:name ="LayoutRoot" Background ="White" >
< Canvas Canvas.top ="20" >
< TextBlock Canvas.top ="10" Canvas.left ="20" > 请输入您的姓名: </ TextBlock >
< TextBox x:name ="Userinput" WIDth ="200" Height ="30" Canvas.top ="40" Canvas.left ="20" ></ TextBox >
< TextBlock x:name ="Msg" Canvas.top ="90" Canvas.left ="20" Foreground ="Navy" FontSize ="18" WIDth ="500" ></ TextBlock >
< button Click ="button_Click" Content ="单击我" FontSize ="24" WIDth ="160" Height ="60" x:name ="BtnTest" Canvas.top ="160" Canvas.left ="20" ></ button >
< button Click ="JsONbutton_Click" Content ="JavaScript JsON 对象测试" FontSize ="24" WIDth ="300" Height ="50" Canvas.top ="240" Canvas.left ="20" ></ button >
< TextBlock x:name ="Msg2" Canvas.top ="300" Canvas.left ="20" Foreground ="Navy" FontSize ="18" WIDth ="500" ></ TextBlock >
< TextBlock x:name ="Msg3" Canvas.top ="320" Canvas.left ="20" Foreground ="Navy" FontSize ="18" WIDth ="500" ></ TextBlock >
</ Canvas >
</ GrID >
</ UserControl >
Page.xaml.cs:
using System;using System.Collections.Generic;
using System.linq;
using System.windows;
using System.windows.Controls;
using System.windows.documents;
using System.windows.input;
using System.windows.Media;
using System.windows.Media.Animation;
using System.windows.Shapes;
using System.windows.browser;
using System.Runtime.Serialization.Json;
namespace SilverlightApplication1
{
public partial class Page : UserControl
{
public Page()
{
InitializeComponent();
}
private voID button_Click( object sender, RoutedEventArgs e)
{
string UserinputContent = this .Userinput.Text;
if (UserinputContent.Equals(String.Empty))
{
UserinputContent = " Hello Silverlight World! " ;
}
else
{
UserinputContent = " 你好, " + UserinputContent;
}
HTMLWindow win = HTMLPage.Window;
this .Msg.Text = UserinputContent;
win.Alert( " Silverlight 里面d出的对话框。 " + UserinputContent);
// 执行页面中的Js函数:
win.Eval( " getArraytest() " );
Object[] args = { " 将此参数传递给 Js 函数 " };
win.Invoke( " getArrayTest " , args);
// 如果页面中的值
HTMLdocument doc = HTMLPage.document;
doc.GetElementByID( " Username " ).SetAttribute( " value " , this .Userinput.Text);
}
[ScriptableMember()]
public string InterInvole()
{
string username = HTMLPage.document.GetElementByID( " Username " ).GetAttribute( " value " );
this .Userinput.Text = username;
this .Msg.Text = " 您输入了: " + username;
return " 你从Js脚本中调用了 Silverlight 里面的方法。 " ;
}
private voID JsONbutton_Click( object sender, RoutedEventArgs e)
{
ScriptObject so = HTMLPage.Window.Invoke( " ReturnObject " , null ) as ScriptObject;
Staple s = so.ConvertTo < Staple > ();
this .Msg2.Text = " 大家好,我在 JavaScript JsON 对象中的名称是: " + s.Username;
}
// 接受HTML页面传递的 JsON 字符串
[ScriptableMember()]
public voID ReveiveJsON( string JsonString)
{
// 注意引用:System.Runtime.Serialization.Json
DataContractJsonSerializer Json = new DataContractJsonSerializer( typeof (Staple));
System.IO.MemoryStream ms = new System.IO.MemoryStream(System.Text.EnCoding.Unicode.GetBytes(JsonString));
Staple staple = new Staple();
staple = (Staple)Json.Readobject(ms);
Msg3.Text = " UserID = " + staple.UserID.ToString() + " , Username = " + staple.Username;
}
}
public class Staple
{
public string Username { set ; get ; }
public Double UserID { set ; get ; }
}
}
App.xaml.cs:
using System;using System.Collections.Generic;
using System.linq;
using System.windows;
using System.windows.Controls;
using System.windows.documents;
using System.windows.input;
using System.windows.Media;
using System.windows.Media.Animation;
using System.windows.Shapes;
using System.windows.browser;
namespace SilverlightApplication1
{
public partial class App : Application
{
public App()
{
this .Startup += this .Application_Startup;
this .Exit += this .Application_Exit;
this .UnhandledException += this .Application_UnhandledException;
InitializeComponent();
}
private voID Application_Startup( object sender, StartupEventArgs e)
{
// Load the main control
Page p = new Page();
HTMLPage.RegisterScriptableObject( " SilverlightApplicationExample " , p);
// 请注意这里的定义方法,如果这里的p写成 new Page(),则JavaScript基本不能给 Userinput 赋值!
this .RootVisual = p;
}
private voID Application_Exit( object sender, EventArgs e)
{
}
private voID Application_UnhandledException( object sender, ApplicationUnhandledExceptionEventArgs e)
{
}
}
}
SilverlightApplication1TestPage.aspx:
<% @ Page Language = " C# " @R_404_6843@EventWireup = " true " %><% @ Register Assembly = " System.Web.Silverlight " namespace = " System.Web.UI.SilverlightControls " TagPrefix = " asp " %>
<! 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 > Silverlight 2托管代码与JavaScript交互的例子 </ Title >
< script type ="text/JavaScript" >
// <!{cdaTA[
// 定义全局变量:
var testvar = " 孟宪会 " ;
// 定义全局函数:
function getArraytest()
{
if (arguments.length > 0 )
{
alert( " Js 对话框:您传递了参数。 " + arguments[ 0 ]);
return arguments[ 0 ];
}
else
{
alert( " Js 对话框:无参数调用。 " );
return " Js 函数返回值 " ;
}
}
function SetUsername()
{
alert(SilverlightPlugin.Content.SilverlightApplicationExample.InterInvole());
}
var Staple = {
UserID: 100 ,
Username: ' 孟宪会 ' ,
SayHello: function (){alert( this .Username)}
};
function ReturnObject()
{
return Staple;
}
function SendJsONToSilverlight()
{
SilverlightPlugin.Content.SilverlightApplicationExample.ReveiveJsON(JsON.stringify(Staple));
}
// 定义Silverlight插件对象
var SilverlightPlugin = null ;;
function pluginLoaded(sender)
{
SilverlightPlugin = sender.get_element();
}
// ]]>
</ script >
< script src ="Json2.Js" type ="text/JavaScript" ></ script >
<!-- http://www.JsON.org/Json2.Js -->
</ head >
< body style ="height: 100%; margin: 0;" >
< form ID ="form1" runat ="server" >
< div style ="border: 2px solID #EEE; margin: 20px;padding:20px" >
请输入你的名字: < input ID ="Username" type ="text" value ="" />
< input type ="button" onclick ="SetUsername()" value ="将名字传递到 Silverlight" /> < input type ="button" onclick ="SendJsONToSilverlight()" value ="将JsON传递到 Silverlight" />
</ div >
< br />
< div style ="border: 2px solID #EEE;margin: 20px;" >
< asp:ScriptManager ID ="ScriptManager1" runat ="server" >
</ asp:ScriptManager >
< asp:Silverlight ID ="Xaml1" runat ="server" OnPluginLoaded ="pluginLoaded" Source ="~/ClIEntBin/SilverlightApplication1.xap" Version ="2.0" WIDth ="600px" Height ="480px" />
</ div >
</ form >
</ body >
</ HTML >
单击“JavaScript JsON 对象测试”按钮,运行结果如下:
原帖地址:http://blog.csdn.net/net_lover/archive/2008/04/06/2254267.aspx 感谢孟宪会老师
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