如何使用javascript暫停/播放/尋找Silverlight視頻

Question

一點點上下文。我希望能夠以編程方式控制來自JavaScript的Amazon Instant Video上的Silverlight視頻播放器。

使用開發者控制檯。我在DOM中找到了視頻播放器元素。

<div id="player_container" style="display: block;"> 
    <object type="application/x-silverlight" 
      data="data:application/x-silverlight," 
      id="player_object" 
      width="50%" 
      height="100%"> 
    <param name="color" value="#ffffff"> 
    <param name="background" value="#000000"> 
    <param name="minRuntimeVersion" value="5.1"> 
    <param name="autoUpgrade" value="false"> 
    ... elided several <param>'s here ... 
    </object> 
</div> 

我再進入在JS REPL在開發者控制檯以下：

> var silver = document.getElementById("player_object"); 

我再試圖跟隨instructions found here。其中指出我應該

> silver.content.findName(SOMETHING_HERE); 

我不能確定使用什麼SOMETHING_HERE，所以我下載Silverlight應用程序與

wget http://www.amazon.com/gp/video/streaming/silverlightPlayer.xap?ie=UTF8&version=104.0-0 
unzip silverlightPlayer.xap?ie=UTF8 

然後我看在解壓縮AppManifest.xaml：

<Deployment xmlns="http://schemas.microsoft.com/client/2007/deployment" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" ExternalCallersFromCrossDomain="ScriptableOnly" EntryPointAssembly="Amazon.ATVSilverlightPlayer" EntryPointType="Amazon.ATVSilverlightWebPlayer.App" RuntimeVersion="5.0.61118.0"> 
    <Deployment.Parts> 
    <AssemblyPart x:Name="Amazon.ATVSilverlightPlayer" Source="Amazon.ATVSilverlightPlayer.dll" /> 
    <AssemblyPart x:Name="Amazon.AIV.Utilities" Source="Amazon.AIV.Utilities.dll" /> 
    <AssemblyPart x:Name="Amazon.Common" Source="Amazon.Common.dll" /> 
    <AssemblyPart x:Name="AmazonPlayer.Themes.DarkGray" Source="AmazonPlayer.Themes.DarkGray.dll" /> 
    <AssemblyPart x:Name="AtvAdsManager" Source="AtvAdsManager.dll" /> 
    <AssemblyPart x:Name="ATVQos" Source="ATVQos.dll" /> 
    <AssemblyPart x:Name="Microsoft.Logging.LocalConnection" Source="Microsoft.Logging.LocalConnection.dll" /> 
    <AssemblyPart x:Name="Microsoft.SilverlightMediaFramework.Core" Source="Microsoft.SilverlightMediaFramework.Core.dll" /> 
    <AssemblyPart x:Name="Microsoft.SilverlightMediaFramework.Diagnostics" Source="Microsoft.SilverlightMediaFramework.Diagnostics.dll" /> 
    <AssemblyPart x:Name="Microsoft.SilverlightMediaFramework.Logging" Source="Microsoft.SilverlightMediaFramework.Logging.dll" /> 
    <AssemblyPart x:Name="Microsoft.SilverlightMediaFramework.Plugins" Source="Microsoft.SilverlightMediaFramework.Plugins.dll" /> 
    <AssemblyPart x:Name="Microsoft.SilverlightMediaFramework.Plugins.Monitoring" Source="Microsoft.SilverlightMediaFramework.Plugins.Monitoring.dll" /> 
    <AssemblyPart x:Name="Microsoft.SilverlightMediaFramework.Plugins.Progressive" Source="Microsoft.SilverlightMediaFramework.Plugins.Progressive.dll" /> 
    <AssemblyPart x:Name="Microsoft.SilverlightMediaFramework.Plugins.SmoothStreaming" Source="Microsoft.SilverlightMediaFramework.Plugins.SmoothStreaming.dll" /> 
    <AssemblyPart x:Name="Microsoft.SilverlightMediaFramework.Plugins.TimedText" Source="Microsoft.SilverlightMediaFramework.Plugins.TimedText.dll" /> 
    <AssemblyPart x:Name="Microsoft.SilverlightMediaFramework.Utilities" Source="Microsoft.SilverlightMediaFramework.Utilities.dll" /> 
    <AssemblyPart x:Name="Microsoft.Web.Media.SmoothStreaming" Source="Microsoft.Web.Media.SmoothStreaming.dll" /> 
    <AssemblyPart x:Name="Newtonsoft.Json" Source="Newtonsoft.Json.dll" /> 
    <AssemblyPart x:Name="System.Json" Source="System.Json.dll" /> 
    <AssemblyPart x:Name="System.Xml.Linq" Source="System.Xml.Linq.dll" /> 
    <AssemblyPart x:Name="System.ComponentModel.Composition" Source="System.ComponentModel.Composition.dll" /> 
    <AssemblyPart x:Name="System.Xml.Serialization" Source="System.Xml.Serialization.dll" /> 
    <AssemblyPart x:Name="System.ComponentModel.Composition.Initialization" Source="System.ComponentModel.Composition.Initialization.dll" /> 
    <AssemblyPart Source="de/Amazon.ATVSilverlightPlayer.resources.dll" /> 
    <AssemblyPart Source="en-GB/Amazon.ATVSilverlightPlayer.resources.dll" /> 
    <AssemblyPart Source="ja/Amazon.ATVSilverlightPlayer.resources.dll" /> 
    <AssemblyPart Source="de/System.Json.resources.dll" /> 
    <AssemblyPart Source="ja/System.Json.resources.dll" /> 
    <AssemblyPart Source="de/System.Xml.Linq.resources.dll" /> 
    <AssemblyPart Source="ja/System.Xml.Linq.resources.dll" /> 
    <AssemblyPart Source="de/System.ComponentModel.Composition.resources.dll" /> 
    <AssemblyPart Source="ja/System.ComponentModel.Composition.resources.dll" /> 
    <AssemblyPart Source="de/System.Xml.Serialization.resources.dll" /> 
    <AssemblyPart Source="ja/System.Xml.Serialization.resources.dll" /> 
    <AssemblyPart Source="de/System.ComponentModel.Composition.Initialization.resources.dll" /> 
    <AssemblyPart Source="ja/System.ComponentModel.Composition.Initialization.resources.dll" /> 
    </Deployment.Parts> 
</Deployment> 

使用silver.content.findName(SOMETHING_HERE)時，我試着用SOMETHING_HERE代替了.xaml文件中x:Name的許多值。總是返回null。我想得到一個句柄，讓我播放/暫停/從我自己的JavaScript控制檯尋找亞馬遜即時視頻？我應該如何取得成功？

Answer 1

應用程序清單不是實際的Silverlight應用程序，它定義了xap文件中的程序集組成了Silverlight應用程序。您嘗試訪問的Silverlight MediaElement是在包含在應用清單中列出的某個dll中的xaml文件中定義的，Amazon.ATVSilverlightPlayer.dll是我開始尋找的地方。我喜歡.NET Reflector檢查dll。

通過名稱引用MediaElement是一種脆弱的方法，因爲將x：name屬性分配給Silverlight元素是可選的，Amazon可以在任何時候更改它。你可以遍歷Silverlight應用程序可視化樹，並按照此處描述的方法尋找一個類型的MediaElement的對象：Javascript array of TextBlock elements from Xaml file

我不得不稍微改變它來得到它的工作對我來說：

var hasLoaded = false; 

    function onSilverlightLoad(sender) { 
     if (hasLoaded) { 
      return; 
     } 
     forEachDescendant(document.getElementById('silverlightObject').content.Root); 
     hasLoaded = true; 
    } 

    function forEachDescendant(elem) { 
     if (elem != null) { 
      console.log('Type: ' + elem.toString()); 
      if (typeof elem.children == 'object') { 
       for (var i = 0; i < elem.children.count; i++) { 
        var child = elem.children.getItem(i); 
        forEachDescendant(child); 
       } 
      } 
      else if (typeof elem.content == 'object') { 
       forEachDescendant(elem.content); 
      } 
     } 
    }