patch up guide\dependency-injection.jade after official updates.

public/docs/ts/latest/guide/dependency-injection.jade

@@ -19,12 +19,18 @@ block includes
   然后，我们将学习在Angular应用中该[如何使用它](#angular-di)。
 
   - [Why dependency injection?](#why-dependency-injection)
+  - [为什么依赖注入？](#why-dependency-injection)
   - [Angular dependency injection](#angular-dependency-injection)
+  - [Angular依赖注入](#angular-dependency-injection)
   - [Injector providers](#injector-providers)
+  - [注入器提供商](#injector-providers)
   - [Dependency injection tokens](#dependency-injection-tokens)
+  - [依赖注入令牌](#dependency-injection-tokens)
   - [Summary](#summary)
+  - [总结](#summary)
 
 p Run the #[+liveExampleLink2()].
+p 运行#[+liveExampleLink2('在线例子')].
 
 .l-main-section#why-di
 :marked
@@ -115,13 +121,12 @@ p Run the #[+liveExampleLink2()].
 
   我们该如何让`Car`更强壮、有弹性以及可测试？
 
-  That's super easy. We change our `Car` constructor to a version with DI:
-
-  答案超级简单。我们把`Car`的构造函数改造成使用DI的版本：
-
   <a id="ctor-injection"></a>
   That's super easy. We change our `Car` constructor to a version with DI:
 
+  <a id="ctor-injection"></a>
+  答案超级简单。我们把`Car`的构造函数改造成使用DI的版本：
+
 +makeTabs(
   'dependency-injection/ts/app/car/car.ts, dependency-injection/ts/app/car/car-no-di.ts',
   'car-ctor, car-ctor',
@@ -333,10 +338,15 @@ block ctor-syntax
     [separate concern](https://en.wikipedia.org/wiki/Separation_of_concerns),
     we suggest that you
     write the service code in its own file.
+
+    因为服务是一个[分离关注点](https://en.wikipedia.org/wiki/Separation_of_concerns)，
+    我们建议你把服务代码放到它自己的文件里。
   +ifDocsFor('ts')
     :marked
       See [this note](#one-class-per-file) for details.
 
+      到[这个笔记](#one-class-per-file)看更多信息。
+
 +makeExample('dependency-injection/ts/app/heroes/hero.service.1.ts',null, 'app/heroes/hero.service.ts' )
 
 :marked
@@ -352,6 +362,8 @@ block ctor-syntax
     Notice the `@Injectable()` #{_decorator} above the service class.
     We'll discuss its purpose [shortly](#injectable).
 
+    注意服务类上面这个`@Injectable()`装饰器。我们[很快](#injectable)会讨论它的用途。
+
 - var _perhaps = _docsFor == 'dart' ? '' : 'perhaps';
 .l-sub-section
   :marked
@@ -467,7 +479,7 @@ block ctor-syntax
 .l-sub-section
   :marked
     #### Focus on the constructor
-    ### 来看构造函数
+    #### 来看构造函数
 
     Adding a parameter to the constructor isn't all that's happening here.
 
@@ -482,19 +494,28 @@ block ctor-syntax
     Also recall that the parent component (`HeroesComponent`)
     has `providers` information for `HeroService`.
 
+    注意构造函数参数有类型`HeroService`，并且`HeroListComponent`类有一个`@Component`装饰器
+    （往上翻可以确认）。另外，记得父级组件（`HeroesComponent`）有`HeroService`的`providers`信息。
+
     The constructor parameter type, the `@Component` #{_decorator},
     and the parent's `providers` information combine to tell the
     Angular injector to inject an instance of
     `HeroService` whenever it creates a new `HeroListComponent`.
 
+    该构造函数类型、`@Component`装饰器、父级的`providers`信息这三个合起来，一起告诉Angular的注入器，在任何时候新建一个新的`HeroListComponent`的时候，注入一个`HeroService`的实例。
+
 #di-metadata
 :marked
   ### Implicit injector creation
 
+  ### 显性注入器的创建
+
   When we introduced the idea of an injector above, we showed how to
   use it to create a new `Car`. Here we also show how such an injector
   would be explicitly created:
 
+  当我们在上面介绍注入器的时候，我们展示了如何使用它创建一个新`Car`。这里，我们也展示一下如何显性的创建这样的注入器：
+
 +makeExample('dependency-injection/ts/app/car/car-injector.ts','injector-create-and-call')(format=".")
 
 :marked
@@ -587,12 +608,15 @@ block ctor-syntax
 //- FIXME refer to Dart API when that page becomes available.
 - var injMetaUrl = 'https://angular.io/docs/ts/latest/api/core/index/InjectableMetadata-class.html';
 h3#injectable Why @Injectable()?
+h3#injectable 为何@Injectable()?
 :marked
   **<a href="#{injMetaUrl}">@Injectable()</a>** marks a class as available to an
   injector for instantiation. Generally speaking, an injector will report an
   error when trying to instantiate a class that is not marked as
   `@Injectable()`.
 
+  **<a href="#{injMetaUrl}">@Injectable()</a>**标志着一个类可以被一个注入器实例化。通常来讲，在试图实例化一个没有被标识为`@Injectable()`的类时候，注入器将会报告错误。
+
 block injectable-not-always-needed-in-ts
   .l-sub-section
     :marked
@@ -602,21 +626,31 @@ block injectable-not-always-needed-in-ts
       We need it because Angular requires constructor parameter metadata
       in order to inject a `Logger`.
 
+      在这里，我们可以在我们第一版的`HeroService`里面省略`@Injectable()`，因为它没有注入的参数。但是现在我们必须要有它，因为我们的服务有了一个注入的依赖。我们需要它，因为Angular需要构造函数参数的元数据来注入一个`Logger`。
+
   .callout.is-helpful
     header Suggestion: add @Injectable() to every service class
+    header 建议：为每一个服务类都添加@Injectable()
     :marked
       We recommend adding `@Injectable()` to every service class, even those that don't have dependencies
       and, therefore, do not technically require it. Here's why:
 
+      我们建议为每个服务类都添加`@Injectable()`，包括那些没有依赖所以技术上不需要它的。因为：
+
     ul(style="font-size:inherit")
       li <b>Future proofing:</b> No need to remember <code>@Injectable()</code> when we add a dependency later.
+      li <b>面向未来:</b> 没有必要记得在后来添加了一个依赖的时候添加<code>@Injectable()</code>。
       li <b>Consistency:</b> All services follow the same rules, and we don't have to wonder why #{_a} #{_decorator} is missing.
+      li <b>一致性:</b>所有的服务都遵循同样的规则，并且我们不需要考虑为什么少一个装饰器。
+
 
 :marked
   Injectors are also responsible for instantiating components
   like `HeroesComponent`. Why haven't we marked `HeroesComponent` as
   `@Injectable()`?
 
+  注入器同时负责实例化像`HerosComponent`这样的组件。为什么我们不标记`HerosComponent`为`@Injectable()`呢？
+
   We *can* add it if we really want to. It isn't necessary because the
   `HeroesComponent` is already marked with `@Component`, and this
   !{_decorator} class (like `@Directive` and `@Pipe`, which we'll learn about later)
@@ -624,6 +658,10 @@ block injectable-not-always-needed-in-ts
   fact `InjectableMetadata` #{_decorator}s that
   identify a class as a target for instantiation by an injector.
 
+  如果真的想要这样做，我们*可以*添加它。但是这不是必须的，因为`HerosComponent`已经被`@Component`标识，这个装饰器类（像`@Directive`和`@Pipe`一样，我们一会儿将会学到）
+  是一个<a href="#{injMetaUrl}">InjectableMetadata</a>的子类型。实际上，`InjectableMetadata`装饰器标识着一个类是注入器实例化的目标。
+
+
 block ts-any-decorator-will-do
   .l-sub-section
     :marked
@@ -633,6 +671,10 @@ block ts-any-decorator-will-do
       But of course, it is more meaningful to mark a class using the appropriate
       <a href="#{injMetaUrl}">InjectableMetadata</a> #{_decorator}.
 
+      注入器使用一个类的构造元数据来决定依赖类型，该构造元数据就是构造函数的参数类型所标识的。
+      TypeScript为任何带有一个装饰器的类生成这样的元数据，任何装饰器都生成。
+      当然，使用一个合适的<a href="#{injMetaUrl}">InjectableMetadata</a>装饰器来标识一个类更加有意义。
+
 .callout.is-critical
   header Always include the parentheses
 
@@ -665,6 +707,8 @@ block ts-any-decorator-will-do
 
   Our logger service is quite simple:
 
+  我们的日志服务很简单：
+
 +makeExample('dependency-injection/ts/app/logger.service.ts', null, 'app/logger.service.ts')
 
 block real-logger
@@ -675,6 +719,8 @@ block real-logger
   so we put it in the project's `#{_appDir}` folder, and
   we register it in the `providers` #{_array} of the metadata for our application root component, `AppComponent`.
 
+  我们比较可能在整个应用程序的任何地方都需要一样的日志服务，所以我们把它放到项目的`#{_appDir}`目录，并在应用程序根组件`AppComponent`的元数据的`providers`数组里面注册它。
+
 +makeExcerpt('app/providers.component.ts','providers-logger','app/app.component.ts (excerpt)')
 
 :marked
@@ -683,9 +729,6 @@ block real-logger
   如果我们忘了注册这个日志服务，Angular会在首次查找这个日志服务时，抛出一个异常。
 
 code-example(format="nocode").
-  EXCEPTION: No provider for Logger! (HeroListComponent -> HeroService -> Logger)
-
-
   EXCEPTION: No provider for Logger! (HeroListComponent -> HeroService -> Logger)
   （异常：Logger类没有供应商！(HeroListComponent -> HeroService -> Logger)）
 
@@ -755,18 +798,22 @@ code-example(format="nocode").
 
 //- Dart limitation: the provide function isn't const so it cannot be used in an annotation.
 - var __andProvideFn = _docsFor == 'dart' ? '' : 'and <i>provide</i> object literal';
+- var __andProvideFn = _docsFor == 'dart' ? '' : '和 <i>provide</i> 对象';
 #provide
 :marked
-  ### The *Provider* class !{__andProvideFn}
+  ### *Provider* 类!{__andProvideFn}
-
 :marked
   We wrote the `providers` #{_array} like this:
 
+  我们像下面一样写`providers`数组：
+
 +makeExample('dependency-injection/ts/app/providers.component.ts','providers-1')
 
 :marked
   This is actually a short-hand expression for a provider registration using the _provider_ object literal.
 
+  这实际上是使用_provider_对象常量注册供应商的缩写表达式。
+
 +makeExample('dependency-injection/ts/app/providers.component.ts','providers-3a')
 
 block provider-ctor-args
@@ -886,7 +933,6 @@ block dart-diff-const-metadata-ctor
   which makes this object play the logger role.
 
   于是我们可以通过`useValue`选项来注册一个供应商，它会让这个对象直接扮演logger的角色。
-+makeExample('dependency-injection/ts/app/providers.component.ts','providers-7')(format=".")
 
 - var stylePattern = { otl: /(useValue: \w*)/gm };
 +makeExample('dependency-injection/ts/app/providers.component.ts','providers-7', '', stylePattern)(format=".")
@@ -896,6 +942,8 @@ block dart-diff-const-metadata-ctor
   [Non-class dependencies](#non-class-dependencies) and
   [OpaqueToken](#opaquetoken) sections.
 
+  在[非类依赖](#non-class-dependencies)和[OpaqueToken](#opaquetoken)查看更多`useValue`的例子。
+
 #factory-provider
 :marked
   ### Factory providers
@@ -1065,17 +1113,18 @@ block dart-diff-const-metadata-ctor
 //- TODO: if function injection is useful explain or illustrate why.
 :marked
   ### Non-class dependencies
-p
+  ### 非类依赖
-  | What if the dependency value isn't a class? Sometimes the thing we want to inject is a
+
-  block non-class-dep-eg
+  What if the dependency value isn't a class? Sometimes the thing we want to inject is a string, function, or object.
-    span string, function, or object.
+
-p
+  如果依赖值不是一个类呢？有时候我们想要注入的东西是一个字符串，函数或者对象。
-  | Applications often define configuration objects with lots of small facts
+
-  | (like the title of the application or the address of a web API endpoint)
+  Applications often define configuration objects with lots of small facts(like the title of the application or
-  block config-obj-maps
+  the address of a web API endpoint) &nbsp;but these configuration objects aren't always instances of a class.
-    | &nbsp;but these configuration objects aren't always instances of a class.
+  They can be object literals &nbsp;such as this one:
-    | They can be object literals
+
-  | &nbsp;such as this one:
+  应用程序经常为很多很小的因素（比如应用程序的标题，或者一个网络API终点的地址）定义配置对象，但是这些配置对象不总是类的实例。
+  他们可能是对象，比如下面这个：
 
 +makeExample('dependency-injection/ts/app/app.config.ts','config','app/app-config.ts (excerpt)')(format='.')
 
@@ -1167,12 +1216,16 @@ block dart-map-alternative
 #optional
 :marked
   ## Optional dependencies
+  ## 可选依赖
 
   Our `HeroService` *requires* a `Logger`, but what if it could get by without
   a logger?
   We can tell Angular that the dependency is optional by annotating the
   constructor argument with `@Optional()`:
 
+  我们的`HeroService`*需要*一个`Logger`，但是如果它可以不用一个Logger就行呢？
+  我们可以通过把构造函数的参数标记为`@Optional()`来告诉Angular该依赖是可选的：
+
 +ifDocsFor('ts')
   +makeExample('dependency-injection/ts/app/providers.component.ts','import-optional', '')
 +makeExample('dependency-injection/ts/app/providers.component.ts','provider-10-ctor', '')(format='.')
@@ -1182,6 +1235,8 @@ block dart-map-alternative
   don't register a logger somewhere up the line, the injector will set the
   value of `logger` to null.
 
+  当使用`@Optional()`时，我们的代码必须要为一个空值做准备。如果我们不在组件或父级组件中注册一个`logger`的话，注入器会设置该`logger`的值为空null。
+
 .l-main-section
 :marked
   ## Summary
@@ -1206,7 +1261,7 @@ block dart-map-alternative
 .l-main-section#explicit-injector
 :marked
   ## Appendix: Working with injectors directly
-  ### 附录：直接使用注入器工作
+  ## 附录：直接使用注入器工作
 
   We rarely work directly with an injector.
   Here's an `InjectorComponent` that does.