随着 Windows Phone 8.1 GDR1 + Cortana 中文版的发布，相信有很多用户或开发者都在调戏 Windows Phone 的语音私人助理 Cortana 吧，在世界杯的时候我亲测 Cortana 预测德国和阿根廷的比赛很准的。（题外话扯远了），可是作为开发者我们怎么将Cortana集成到应用中呢，今天我用一点时间给大家介绍一下如何使用 voice command 集成 Windows Phone 8.1 的应用。
首先要明确两个名词 Voice command & Voice Command Definition 即 VCD文件，相信做过windows Phone 8.0 开发的朋友应该有所了解，通过注册VCD文件 Windows phone 8.0 的应用当中就可以实现 voice command 的功能，如果你不了解请先读一下我之前的文章（这里我就不在过多介绍 8.0 Voice command 的重复内容了），Windows Phone 8 语音 - Speech for Windows Phone 8 快速了解一下Windows Phone 开发语音功能的前期准备工作。
简单的说在 Windows Phone 8.0 voice command 功能比较简单，主要是通过 Voice Command Name 判断预制在VCD文件中的几个命令。
在 Windows Phone 8.1 应用中 Cortana 提供了更强的自然语言识别（Natural language recognition）
当然 VCD 文件的中的 grammars 也得到了扩充，并且区别两个OS版本的
http://schemas.microsoft.com/voicecommands/1.0 for Windows Phone 8.0 Voice Command and Cortana compatible.
http://schemas.microsoft.com/voicecommands/1.1 only for Widnows Phone 8.1 Cortnan.
详细内容请参考
Windows Phone 8.0: Voice command element and attribute reference for Windows Phone 8
Windows Phone 8.1: Voice command elements and attributes
通过 8.0 和 8.1 VCD 文件属性支持情况来看有一个最主要的区别在8.1 VCD中支持 PhraseTopic 这个属性。
文字说的太抽象了还是贴出代码给大家说说吧：
这里我主要强调说一下 ListenFor 结点和 PhraseTopic 结点。 注意在 Listenfor 结点中的中括号 {dictatedSearchTerms} 是对应的 PhraseTopic 结点中的 Label 属性。同时我们可以把 PhraseTopic 理解成任意内容。最后都可以从Cortana回传到我们的应用当中来。
<VoiceCommands xmlns="http://schemas.microsoft.com/voicecommands/1.1">
<!-- The CommandSet Name is used to programmatically access the CommandSet -->
<CommandSet xml:lang="zh-CN" Name="chineseCommands">
<!-- The CommandPrefix provides an alternative to your full app name for invocation -->
<CommandPrefix> 微软 文档 </CommandPrefix>
<!-- The CommandSet Example appears in the global help alongside your app name -->
<Example> 搜索 构造 函数 </Example>
<Command Name="MSDNSearch">
<!-- The Command example appears in the drill-down help page for your app -->
<Example> 搜索 构造 函数‘ </Example>
<!-- ListenFor elements provide ways to say the command, including references to
{PhraseLists} and {PhraseTopics} as well as [optional] words -->
<ListenFor> 查找 {dictatedSearchTerms} </ListenFor>
<ListenFor> 搜 {dictatedSearchTerms} </ListenFor>
<ListenFor> 搜索 {dictatedSearchTerms} </ListenFor>
<ListenFor> 查 {dictatedSearchTerms} </ListenFor>
<ListenFor> 找 {dictatedSearchTerms} </ListenFor>
<!--Feedback provides the displayed and spoken text when your command is triggered -->
<Feedback> 查找 MSDN... </Feedback>
<!-- Navigate specifies the desired page or invocation destination for the Command-->
<Navigate Target="MainPage.xaml" />
</Command>
<Command Name="MSDNNaturalLanguage">
<Example> 我 想 去 Windows 手机 开发 中心 </Example>
<ListenFor> {naturalLanguage} </ListenFor>
<Feedback> 启动 MSDN... </Feedback>
<Navigate Target="MainPage.xaml" />
</Command>
<PhraseTopic Label="dictatedSearchTerms" Scenario="Search">
<Subject> MSDN </Subject>
</PhraseTopic>
<PhraseTopic Label="naturalLanguage" Scenario="Natural Language">
<Subject> MSDN </Subject>
</PhraseTopic>
</CommandSet>
</VoiceCommands>
了解完新的VCD文件，在这里我提醒下大家，其实在Windows Phone 8.0的应用中也可以兼容 Cortana的功能的，在8.0的应用当中我们只需要判断一下操作系统的版本然后选择不同的VCD文件向系统注册即可。
首先我们需要把两个版本的VCD文件都存放到项目中来
其次在注册VCD文件的时候根据系统版本进行一下判断即可。
/// <summary>
/// Installs the Voice Command Definition (VCD) file associated with the application.
/// Based on OS version, installs a separate document based on version 1.0 of the schema or version 1.1.
/// </summary>
private async void InstallVoiceCommands()
{
const string wp80vcdPath = "ms-appx:///VoiceCommandDefinition_8.0.xml";
const string wp81vcdPath = "ms-appx:///VoiceCommandDefinition_8.1.xml";
const string chineseWp80vcdPath = "ms-appx:///ChineseVoiceCommandDefinition_8.0.xml";
const string chineseWp81vcdPath = "ms-appx:///ChineseVoiceCommandDefinition_8.1.xml";
try
{
bool using81orAbove = ((Environment.OSVersion.Version.Major >= 8)
&& (Environment.OSVersion.Version.Minor >= 10));
string vcdPath = using81orAbove ? wp81vcdPath : wp80vcdPath;
if (InstalledSpeechRecognizers.Default.Language.Equals("zh-CN", StringComparison.InvariantCultureIgnoreCase))
{
vcdPath = using81orAbove ? chineseWp81vcdPath : chineseWp80vcdPath;
}
Uri vcdUri = new Uri(vcdPath);
await VoiceCommandService.InstallCommandSetsFromFileAsync(vcdUri);
}
catch (Exception vcdEx)
{
Dispatcher.BeginInvoke(() =>
{
MessageBox.Show(String.Format(
AppResources.VoiceCommandInstallErrorTemplate, vcdEx.HResult, vcdEx.Message));
});
}
}
最后在应用当中获取用户的语音输入方法，注意这里也是需要通过 PhraseTopic 结点的 Label 名称获取的。
/// <summary>
/// Takes specific action for a retrieved VoiceCommand name.
/// </summary>
/// <param name="voiceCommandName"> the command name triggered to activate the application </param>
private void HandleVoiceCommand(string voiceCommandName)
{
// Voice Commands can be typed into Cortana; when this happens, "voiceCommandMode" is populated with the
// "textInput" value. In these cases, we‘ll want to behave a little differently by not speaking back.
bool typedVoiceCommand = (NavigationContext.QueryString.ContainsKey("commandMode")
&& (NavigationContext.QueryString["commandMode"] == "text"));
string phraseTopicContents = null;
bool doSearch = false;
switch (voiceCommandName)
{
case "MSDNNaturalLanguage":
if (NavigationContext.QueryString.TryGetValue("naturalLanguage", out phraseTopicContents)
&& !String.IsNullOrEmpty(phraseTopicContents))
{
// We‘ll try to process the input as a natural language query; if we‘re successful, we won‘t
// fall back into searching, since the query will have already been handled.
doSearch = TryHandleNlQuery(phraseTopicContents, typedVoiceCommand);
}
break;
case "MSDNSearch":
// The user explicitly asked to search, so we‘ll attempt to retrieve the query.
NavigationContext.QueryString.TryGetValue("dictatedSearchTerms", out phraseTopicContents);
doSearch = true;
break;
}
if (doSearch)
{
HandleSearchQuery(phraseTopicContents, typedVoiceCommand);
}
}
整个过程就这么简单，心动不如行动，赶快把你的应用加入Cortana 功能让小伙伴儿们调戏一番。
更多参考资料：
Quickstart: Voice commands (XAML)
源码下载：
MSDN Voice Search for Windows Phone 8.1
如何将 Cortana 与 Windows Phone 8.1 应用集成 ( Voice command - Natural language recognition )