动态加载XAP文件

myButton.Click += new RoutedEventHandler(myButton_Click);   
  
    
  
        void myButton_Click(object sender, RoutedEventArgs e)   
  
        {   
  
            WebClient client = new WebClient();   
  
            client.OpenReadCompleted += new OpenReadCompletedEventHandler(webClient_OpenReadCompleted);   
  
    
  
            //打开打包的xap文件   
  
            client.OpenReadAsync(new Uri("Binglang.ExternalProject.xap", UriKind.Relative));   
  
    
  
        }   
  
    
  
        void webClient_OpenReadCompleted(object sender, OpenReadCompletedEventArgs e)   
  
        {   
  
//通过AppManifest.xaml文件取出动态库的信息   
  
             Assembly asm = LoadAssemblyFromXap(e.Result, "Binglang.ExternalProject.dll");   
  
    
  
            ////使用反射创建相关的实例，并在页面上加载   
  
            holder.Children.Clear();   
  
            UIElement element = asm.CreateInstance("Binglang.ExternalProject.MainPage") as UIElement;   
  
            this.holder.Children.Add(element);   
  
    
  
        }   
  
    
  
        /// <summary>   
  
        /// 通过AppManifest.xaml文件取出动态库的信息   
  
        /// </summary>   
  
        /// <param name="packageStream">OpenReadCompletedEventArgs e.Result</param>   
  
        /// <param name="assemblyName">动态库文件名</param>   
  
        /// <returns></returns>   
  
   Assembly LoadAssemblyFromXap(Stream packageStream, string assemblyName)   
  
        {   
  
            //解包，读取AppManifest.xaml文件信息   
  
            string appManifest = new StreamReader(Application.GetResourceStream(new StreamResourceInfo(packageStream, null), new Uri("AppManifest.xaml", UriKind.Relative)).Stream).ReadToEnd();   
  
    
  
            //------------解析AppManifest.xaml信息内容   
  
    
  
            XElement deploymentRoot = XDocument.Parse(appManifest).Root;   
  
            List<XElement> deploymentParts = (from assemblyParts in deploymentRoot.Elements().Elements()   
  
                                              select assemblyParts).ToList();   
  
    
  
            Assembly asm = null;   
  
            foreach (XElement xElement in deploymentParts)   
  
            {   
  
                string source = xElement.Attribute("Source").Value;   
  
                AssemblyPart asmPart = new AssemblyPart();   
  
                StreamResourceInfo streamInfo = Application.GetResourceStream(new StreamResourceInfo(packageStream, "application/binary"), new Uri(source, UriKind.Relative));   
  
                if (source == assemblyName)   
  
                {   
  
                    asm = asmPart.Load(streamInfo.Stream);   
  
                }   
  
                else  
  
                {   
  
                    asmPart.Load(streamInfo.Stream);   
  
                }   
  
            }   
  
            return asm;   
  
        }