AndroidAnnotations开源框架

浏览数：172 / 时间：2015年06月11日

这段时间学习别人的源码，需要AndroidAnnotations这个开源的框架，学习下，他的地在：https://github.com/excilys/androidannotations文档的地址在：https://github.com/excilys/androidannotations/wiki 正如在github上他的主页上所说：Fast Android Development. Easy maintenance.它具有快速Android开发，易于维护的优点。

特点：

Features

Dependency injection: inject views, extras, system services, resources, ...(DI：依赖注入)
Simplified threading model: annotate your methods so that they execute on the UI thread or on a background thread.（简化的线程模型）
Event binding: annotate methods to handle events on views, no more ugly anonymous listener classes!（事件绑定）
REST client: create a client interface, AndroidAnnotations generates the implementation.
No magic: As AndroidAnnotations generate subclasses at compile time, you can check the code to see how it works.
AndroidAnnotations provide those good things and even more for less than 50kb, without any runtime perf impact!

先看下面的代码：

@EActivity(R.layout.translate) // Sets content view to R.layout.translate
public class TranslateActivity extends Activity {

    @ViewById // Injects R.id.textInput
    EditText textInput;

    @ViewById(R.id.myTextView) // Injects R.id.myTextView
    TextView result;

    @AnimationRes // Injects android.R.anim.fade_in
    Animation fadeIn;

    @Click // When R.id.doTranslate button is clicked 
    void doTranslate() {
         translateInBackground(textInput.getText().toString());
    }

    @Background // Executed in a background thread
    void translateInBackground(String textToTranslate) {
         String translatedText = callGoogleTranslate(textToTranslate);
         showResult(translatedText);
    }

    @UiThread // Executed in the ui thread
    void showResult(String translatedText) {
         result.setText(translatedText);
         result.startAnimation(fadeIn);
    }

    // [...]
}

//===================================================================

AndroidAnnotations works in a very simple way. It automatically adds an extra compilation step that generates source code, using the standard Java Annotation Processing Tool.

What source code ? For each enhanced class, for example each @EActivity annotated activity, a subclass of this activity is generated, with the same name plus an underscore appended at the end.(会生成一个子类)

For instance, the following class:

package com.some.company;
@EActivity
public class MyActivity extends Activity {
  // ...
}

Will generate the following subclass, in the same package but in another source folder:(生成一个MyActivity_的子类)

package com.some.company;
public final class MyActivity_ extends MyActivity {
  // ...
}

This subclass adds behavior to your activity by overriding some methods (for instanceonCreate()), yet delegating the calls to super.

That is the reason why you must add _ to your activity names in AndroidManifest.xml:（清单文件中这样配置生成的子类）

<activity android:name=".MyListActivity_" />

Starting an annotated activity

In Android, you usually start an activity this way:

startActivity(this, MyListActivity.class);

However, with AndroidAnnotations, the real activity that must be started isMyListActivity_:

startActivity(this, MyListActivity_.class);

Intent Builder

Since AndroidAnnotations 2.4

We provide a static helper to let you start the generated activity:

// Starting the activity
MyListActivity_.intent(context).start();

// Building an intent from the activity
Intent intent = MyListActivity_.intent(context).get();

// You can provide flags
MyListActivity_.intent(context).flags(FLAG_ACTIVITY_CLEAR_TOP).start();

// You can even provide extras defined with @Extra in the activity
MyListActivity_.intent(context).myDateExtra(someDate).start();

Since AndroidAnnotations 2.7

You can also use the startActivityForResult() equivalent:

MyListActivity_.intent(context).startForResult();

Starting an annotated Service

In Android, you usually start a service this way:

startService(this, MyService.class);

However, with AndroidAnnotations, the real Service that must be started is MyService_:

startService(this, MyService_.class);

Intent Builder

Since AndroidAnnotations 2.7

We provide a static helper to let you start the generated service:

// Starting the service
MyService_.intent(context).start();

// Building an intent from the activity
Intent intent = MyService_.intent(context).build();

// You can provide flags
MyService_.intent(context).flags(Intent.FLAG_GRANT_READ_URI_PERMISSION).start(