我在
Android项目中使用
Dagger依赖注入,可以编译和构建应用程序.对象图看起来是正确的和工作的,但是当我添加匕首编译器作为依赖,以便在编译时获取错误,它报告一些奇怪的错误：
[ERROR] error: No binding for com.squareup.tape.TaskQueue<com.atami \
.mgodroid.io.NodeIndexTask> required by com.atami \
.mgodroid.ui.NodeIndexListFragment for com.atami.mgodroid \
.modules.OttoModule
[ERROR] error: No binding for com.squareup.tape.TaskQueue<com.atami \
.mgodroid.io.NodeTask> required by com.atami \
.mgodroid.ui.NodeFragment for com.atami.mgodroid.modules.OttoModule
[ERROR] error: No injectable members on com.squareup.otto.Bus. Do you want
to add an injectable constructor? required by com.atami. \
mgodroid.io.NodeIndexTaskService for
com.atami.mgodroid.modules.TaskQueueModule
Otto错误看起来像Eric Burke在他的Android App Anatomy演示文稿中提到的没有一个@Provides注释,但是你可以在下面看到.
我的Otto和TaskQueue模块如下：
@Module(
entryPoints = {
MGoBlogActivity.class,NodeIndexListFragment.class,NodeFragment.class,NodeActivity.class,NodeCommentFragment.class,NodeIndexTaskService.class,NodeTaskService.class
}
)
public class OttoModule {
@Provides
@Singleton
Bus provideBus() {
return new AsyncBus();
}
/**
* Otto EventBus that posts all events on the Android main thread
*/
private class AsyncBus extends Bus {
private final Handler mainThread = new Handler(Looper.getMainLooper());
@Override
public void post(final Object event) {
mainThread.post(new Runnable() {
@Override
public void run() {
AsyncBus.super.post(event);
}
});
}
}
}
…
@Module(
entryPoints = {
NodeIndexListFragment.class,NodeTaskService.class
}
)
public class TaskQueueModule {
private final Context appContext;
public TaskQueueModule(Context appContext) {
this.appContext = appContext;
}
public static class IOTaskInjector<T extends Task>
implements TaskInjector<T> {
Context context;
/**
* Injects Dagger dependencies into Tasks added to TaskQueues
*
* @param context the application Context
*/
public IOTaskInjector(Context context) {
this.context = context;
}
@Override
public void injectMembers(T task) {
((MGoBlogApplication) context.getApplicationContext())
.objectGraph().inject(task);
}
}
public static class ServiceStarter<T extends Task>
implements ObjectQueue.Listener<T> {
Context context;
Class<? extends Service> service;
/**
* Starts the provided service when a Task is added to the queue
*
* @param context the application Context
* @param service the Service to start
*/
public ServiceStarter(Context context,Class<? extends Service> service) {
this.context = context;
this.service = service;
}
@Override
public void onAdd(ObjectQueue<T> queue,T entry) {
context.startService(new Intent(context,service));
}
@Override
public void onRemove(ObjectQueue<T> queue) {
}
}
@Provides
@Singleton
TaskQueue<NodeIndexTask> provideNodeIndexTaskQueue() {
ObjectQueue<NodeIndexTask> delegate =
new InMemoryObjectQueue<NodeIndexTask>();
TaskQueue<NodeIndexTask> queue = new TaskQueue<NodeIndexTask>(
delegate,new IOTaskInjector<NodeIndexTask>(appContext));
queue.setListener(new ServiceStarter<NodeIndexTask>(
appContext,NodeIndexTaskService.class));
return queue;
}
@Provides
@Singleton
TaskQueue<NodeTask> provideNodeTaskQueue() {
ObjectQueue<NodeTask> delegate =
new InMemoryObjectQueue<NodeTask>();
TaskQueue<NodeTask> queue = new TaskQueue<NodeTask>(
delegate,new IOTaskInjector<NodeTask>(appContext));
queue.setListener(new ServiceStarter<NodeTask>(
appContext,NodeTaskService.class));
return queue;
}
}
…
/**
* Module that includes all of the app's modules. Used by Dagger
* for compile time validation of injections and modules.
*/
@Module(
includes = {
MGoBlogAPIModule.class,OttoModule.class,TaskQueueModule.class
}
)
public class MGoBlogAppModule {
}
解决方法
匕首的全图分析从一个完整的模块中工作.即@Module(complete = true),这是默认值.因为它是默认值,默认情况下,匕首将假定所有绑定都可以从该模块或其明确包含的模块中获得.
在这种情况下,您已经给出了两个声明完整的模块,但是Dagger无法在编译时将这些模块绑定在一起,而无需额外的信号.简而言之,没有OttoModule知道TaskQueueModule,编译器将尝试分析OttoModule的声明完整性,并且失败,因为它现在不关于TaskQueueModule.
修改OttoModule的注释：
@Module(
includes = TaskQueueModule.class,entryPoints = {
MGoBlogActivity.class,NodeTaskService.class
}
)
然后Dagger会知道,为了完成OttoModule,它将其他模块作为其完整定义的一部分.
注意：匕首编译器无法检测到TaskQueueModule在类路径上,只是“知道”开发人员打算将其与OttoModule一起使用,而没有附加信号.例如,您可能有几个模块可以定义任务队列,哪些模块可以选择？声明必须明确.
