好的。让我试着把这种情况分解一下，因为我认为标题可能有点不清楚。在继续之前，我会尽可能说，我已经尝试将这个应用程序的基本结构建立在官方 dagger 示例的基础上。
本质上，我想要做的是能够将LocationClient注入我的SplashActivity，以便在LocationClient.connect()打开应用程序后立即建立连接（通过 ）。
现在，很明显，LocationClient 不能通过任何类型的默认构造函数注入（它需要一些非常具体的东西（上下文和一些回调）。所以，我 @Provides在我的ActivityModule:
@Provides
@Singleton
LocationClient providesLocationClient(@ForApplication Context context, LocationService service) {
return new LocationClient(context, service, service);
}
LocationService是我为实现所需的回调而创建的类LocationClient。我还通过@Provides我的ActivityModule：
@Provides
@Singleton
LocationService providesLocationService(@ForActivity Context context, Logger logger) {
return new LocationService(context, logger);
}
我会在最后提供所有相关文件的完整代码，以供参考。
所以，我想@Inject在LocationClient我的SplashActivity. 但是，当我这样做时，我收到以下错误：
No injectable members on com.google.android.gms.location.LocationClient. Do you want to add an injectable constructor? required by class m.myapp.android.storemode.presentation.activity.SplashActivity
我发现只有两种方法可以避免这个错误，而且都不能完成我需要的。我可以
将注入移动
LocationClient到片段上。这不好，因为这一点对于应用程序的流程来说太晚了。我希望能够在LocationClient此时开始调用 ，这需要建立连接。@Provides在for中删除对 Activity Context 的引用LocationService，并将@Providesfrom移动ActivityModule到AndroidModule。这也不好，因为我需要 Activity 上下文来完成回调中的一些事情（如在 Google 示例中设置新的位置服务所见）。
所以，这就是我陷入的困境。我希望这有点道理。我很难解释它，因为它太分散了。下面是 my ActivityModule、 my AndroidModule、 my Application 文件和 my的代码BaseActivity：
活动模块
@Module(
injects = {MainActivity.class,
SplashActivity.class,
HomeFragment.class,
StoreLocatorFragment.class,
BrowseProductsFragment.class,
BrowseProductCategoriesFragment.class},
includes = {NetworkImageModule.class, ApiModule.class, WatchListModule.class},
complete = false
)
public class ActivityModule {
private final BaseActivity mActivity;
public ActivityModule(BaseActivity activity) {
this.mActivity = activity;
}
/**
* Allow the mActivity context to be injected but require that it be annotated with {@link
* ForActivity @ForActivity} to explicitly differentiate it from application context.
*/
@Provides
@Singleton
@ForActivity
Context provideActivityContext() {
return mActivity;
}
@Provides
@Singleton
KeyboardHider provideKeyboardHider(InputMethodManager imm) {
return new KeyboardHider(imm);
}
@Provides
ProgressDialog providesProgressDialog() {
return new ProgressDialog(mActivity);
}
@Provides
@Singleton
LocationService providesLocationService(@ForActivity Context context, Logger logger) {
return new LocationService(context, logger);
}
@Provides
@Singleton
LocationClient providesLocationClient(@ForApplication Context context, LocationService service) {
return new LocationClient(context, service, service);
}
@Provides
@Singleton
PIVenueIdService providesPiVenueIdService(LocationClient locationClient) {
return new PIVenueIdService(locationClient);
}
}
安卓模块
@Module(library = true)
public class AndroidModule {
/**
* SharedPreferences name
*/
public static final String PREFERENCE_NAME = AndroidModule.class
.getPackage()
.getName() +
"Preferences";
private final StoreModeApplication mApplication;
//Only created for testing
public AndroidModule() {
mApplication = null;
}
public AndroidModule(StoreModeApplication application) {
mApplication = checkNotNull(application);
}
/**
* Allow the application context to be injected but require that it be annotated with {@link
* ForApplication @Annotation} to explicitly differentiate it from an activity context.
*/
@Provides
@Singleton
@ForApplication
Context provideApplicationContext() {
return mApplication;
}
@Provides
@Singleton
SharedPreferences provideSharedPreferences() {
return mApplication.getSharedPreferences(PREFERENCE_NAME, Context.MODE_PRIVATE);
}
@Provides
@Singleton
RequestQueue provideRequestQueue() {
return Volley.newRequestQueue(mApplication);
}
@Provides
@Singleton
ActivityManager provideActivityManager() {
return (ActivityManager) mApplication.getSystemService(Context.ACTIVITY_SERVICE);
}
@Provides
@Singleton
LocationManager provideLocationManager() {
return (LocationManager) mApplication.getSystemService(Context.LOCATION_SERVICE);
}
@Provides
@Singleton
Logger provideLoggingService() {
return new LogCatLogger();
}
@Provides
@Singleton
Gson provideGson() {
return new Gson();
}
@Provides
@Singleton
InputMethodManager provideInputMethodManager() {
return (InputMethodManager) mApplication.getSystemService(Context.INPUT_METHOD_SERVICE);
}
}
申请文件
public class StoreModeApplication extends Application {
private static StoreModeApplication sInstance;
private ObjectGraph mGraph;
/**
* Only use this for easy access to inject function
*/
public static StoreModeApplication getInstance() {
return sInstance;
}
@Override
public void onCreate() {
super.onCreate();
// Setup debugging for butterknife
Views.setDebug(BuildConfig.DEBUG);
// Create ability to get instance
sInstance = this;
// Setup DI
mGraph = ObjectGraph.create(getModules().toArray());
}
/**
* Used for injecting dependencies
*
* @param object object that needs dependencies injected
*/
public void inject(Object object) {
mGraph.inject(object);
}
/**
* Gets mGraph.
*
* @return Value of mGraph.
*/
public ObjectGraph getApplicationGraph() {
return mGraph;
}
/**
* Creates a list containing all the modules required for dagger
*/
private List<Object> getModules() {
return Arrays.asList(
new AndroidModule(this),
new ActivityObjectMapperModule(),
new NetworkImageModule()
);
}
基本活动
public abstract class BaseActivity extends Activity {
private ObjectGraph mActivityGraph;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
StoreModeApplication storeModeApplication = StoreModeApplication.getInstance();
mActivityGraph = storeModeApplication.getApplicationGraph()
.plus(
getModules().toArray()
);
mActivityGraph.inject(this);
}
@Override
protected void onDestroy() {
// Eagerly clear the reference to the activity graph to allow it to be garbage collected as
// soon as possible.
mActivityGraph = null;
super.onDestroy();
}
protected List<Object> getModules() {
return Arrays.asList(
new ActivityModule(this),
new StoreLocatorFragmentModule(),
new WatchListModule()
);
}
/**
* Inject the supplied {@code object} using the activity-specific graph.
*/
public void inject(Object object) {
mActivityGraph.inject(object);
}