忆龙2009：Silverlight学习笔记-根据需要动态加载应用程序集

      下面介绍了一种方法，在当前程序集中动态向主机服务器检索并加载程序集的方法。该方法响应用户鼠标单击事件，使用 WebClient@H_874_23@@H_874_23@ 类启动程序集的异步下载，在程序集下载完成后，使用 AssemblyPart@H_874_23@@H_874_23@ 类来动态加载此程序集。

      要实现这个功能，您的应用程序项目中必须已经引用了该程序集，同时，该程序集的"复制本地"@H_874_23@值还必须为"false"@H_874_23@，这样，它将不会部署在应用程序包中。

<UserControl x:Class="SilverlightApplication.HomePage" xmlns="<a href="http://code.js-code.com/tag/http/" target="_blank" class="keywords">http</a>://<a href="http://code.js-code.com/tag/sche/" target="_blank" class="keywords">sche</a>R_67_11845@a<a href="http://code.js-code.com/tag/s/" target="_blank" class="keywords">s.</a>microsoft.com/winfx/2006/xaml/presentation" xmlns:x="<a href="http://code.js-code.com/tag/http/" target="_blank" class="keywords">http</a>://<a href="http://code.js-code.com/tag/sche/" target="_blank" class="keywords">sche</a>R_67_11845@a<a href="http://code.js-code.com/tag/s/" target="_blank" class="keywords">s.</a>microsoft.com/winfx/2006/xaml"> <Grid <a href="http://code.js-code.com/tag/BAC/" target="_blank" class="keywords">BAC</a>kground="S<a href="http://code.js-code.com/tag/Andy/" target="_blank" class="keywords">Andy</a>Brown"> <StackPanel x:Name="stackPanel"> <TextBlock>Page from Host Application</TextBlock> <TextBlock Mou<a href="http://code.js-code.com/tag/SELE/" target="_blank" class="keywords">SELE</a>ftButtonUp="TextBlock_Mou<a href="http://code.js-code.com/tag/SELE/" target="_blank" class="keywords">SELE</a>ftButtonUp" <a href="http://code.js-code.com/tag/curs/" target="_blank" class="keywords">curs</a>or="Hand"> Click Here to Display a UI from the Library Assembly </TextBlock> </StackPanel> </Grid> </UserControl>

using Sy<a href="http://code.js-code.com/tag/stem/" target="_blank" class="keywords">stem</a>; // Uri using Sy<a href="http://code.js-code.com/tag/stem/" target="_blank" class="keywords">stem</a>.Net; // WebClient,Open<a href="http://code.js-code.com/tag/ReadCo/" target="_blank" class="keywords">ReadCo</a>R_67_11845@pletedEventHandler using Sy<a href="http://code.js-code.com/tag/stem/" target="_blank" class="keywords">stem</a>.Windows; // AssemblyPart using Sy<a href="http://code.js-code.com/tag/stem/" target="_blank" class="keywords">stem</a>.Window<a href="http://code.js-code.com/tag/s/" target="_blank" class="keywords">s.</a>Controls; // UserControl using Sy<a href="http://code.js-code.com/tag/stem/" target="_blank" class="keywords">stem</a>.Window<a href="http://code.js-code.com/tag/s/" target="_blank" class="keywords">s.</a>Input; // MouseButtonEventArgs using SilverlightLibrary; // Page namespace SilverlightApplication <a href="http://code.js-code.com/tag/" target="_blank" class="keywords">{</a> public partial class HomePage : UserControl <a href="http://code.js-code.com/tag/" target="_blank" class="keywords">{</a> public HomePage() <a href="http://code.js-code.com/tag/" target="_blank" class="keywords">{</a> InitializeComponent(<a href="http://code.js-code.com/tag/" target="_blank" class="keywords">);</a> } private void TextBlock_Mou<a href="http://code.js-code.com/tag/SELE/" target="_blank" class="keywords">SELE</a>ftButtonUp( ob<a href="http://code.js-code.com/tag/je/" target="_blank" class="keywords">je</a>ct sender,MouseButtonEventArgs <a href="http://code.js-code.com/tag/E/" target="_blank" class="keywords">E)</a> <a href="http://code.js-code.com/tag/" target="_blank" class="keywords">{</a> // Download an "on-demand" assembly. WebClient wc = new WebClient(<a href="http://code.js-code.com/tag/" target="_blank" class="keywords">);</a> wc<a href="http://code.js-code.com/tag/o/" target="_blank" class="keywords">.o</a>pen<a href="http://code.js-code.com/tag/ReadCo/" target="_blank" class="keywords">ReadCo</a>R_67_11845@pleted += <a href="http://code.js-code.com/tag/newope/" target="_blank" class="keywords">new ope</a>n<a href="http://code.js-code.com/tag/ReadCo/" target="_blank" class="keywords">ReadCo</a>R_67_11845@pletedEventHandler(wc_Open<a href="http://code.js-code.com/tag/ReadCo/" target="_blank" class="keywords">ReadCo</a>R_67_11845@pleted<a href="http://code.js-code.com/tag/" target="_blank" class="keywords">);</a> wc<a href="http://code.js-code.com/tag/o/" target="_blank" class="keywords">.o</a>penReadAsync( new Uri("SilverlightLibrary.dll",UriKind.Relativ<a href="http://code.js-code.com/tag/E/" target="_blank" class="keywords">E)</a><a href="http://code.js-code.com/tag/" target="_blank" class="keywords">);</a> } private void wc_Open<a href="http://code.js-code.com/tag/ReadCo/" target="_blank" class="keywords">ReadCo</a>R_67_11845@pleted( ob<a href="http://code.js-code.com/tag/je/" target="_blank" class="keywords">je</a>ct sender,Open<a href="http://code.js-code.com/tag/ReadCo/" target="_blank" class="keywords">ReadCo</a>R_67_11845@pletedEventArgs <a href="http://code.js-code.com/tag/E/" target="_blank" class="keywords">E)</a> <a href="http://code.js-code.com/tag/" target="_blank" class="keywords">{</a> if ((e.Error == null) && (e.Cancelled == <a href="http://code.js-code.com/tag/fal/" target="_blank" class="keywords">fal</a>s<a href="http://code.js-code.com/tag/E/" target="_blank" class="keywords">E)</a>) <a href="http://code.js-code.com/tag/" target="_blank" class="keywords">{</a> // Convert the downloaded stream into an assembly that is // loaded into current AppDomain. AssemblyPart assemblyPart = new AssemblyPart(<a href="http://code.js-code.com/tag/" target="_blank" class="keywords">);</a> assemblyPart.Load(e.Result<a href="http://code.js-code.com/tag/" target="_blank" class="keywords">);</a> DisplayPageFromLibraryAssembly(<a href="http://code.js-code.com/tag/" target="_blank" class="keywords">);</a> } } private void DisplayPageFromLibraryAssembly() <a href="http://code.js-code.com/tag/" target="_blank" class="keywords">{</a> // Create an instance of the Page class in the library assembly. Page page = new Page(<a href="http://code.js-code.com/tag/" target="_blank" class="keywords">);</a> // Display the new Page. thi<a href="http://code.js-code.com/tag/s/" target="_blank" class="keywords">s.</a>stackPane<a href="http://code.js-code.com/tag/l/" target="_blank" class="keywords">l.</a>Children.Add(pag<a href="http://code.js-code.com/tag/E/" target="_blank" class="keywords">E)</a>; } } }