Dagger2在Mvp的应用

@Singleton
@Component(modules = {PresenterModule.class})
public interface PresenterComponent {

    /**
     * 注入点
     * @param activity  表示需要使用DaggerPresenterComponent.create().inject(this);注入的地方，
     *                  注意，此处一定不要使用Activity，需要使用MainActivity，否则的话会报空指针异常。
     *                  因为这里的注入点是什么，就会到该类里面去找。如果写Activity，就会到Activity里面去找，
     *                  而Activity中并没有@inject，即没有需要注入的地方，所以在生成的DaggerPresenterComponent
     *                  中，方法就不会被调用。
     */

    void inject( MainActivity activity);
}

    DownloadQuanCryPre downloadQuanCryPre;
    DownloadQuanDataPre downloadQuanDataPre;
    public PresenterModule(MainActivity activity) {
        downloadQuanCryPre =new DownloadQuanCryPre(activity,activity);
        downloadQuanDataPre =new DownloadQuanDataPre(activity,activity);
    }

}

    @Inject
    public DownloadQuanCryPre downloadQuanCryPre;
    @Inject
    public DownloadQuanDataPre downloadQuanDataPre; 
//oncreate()方法中
DaggerPresenterComponent.builder().presenterModule(new PresenterModule(this)).build().inject(this);

public class BasePresenter<V, T> implements LifeCycleListener {

    protected Reference<V> mViewRef;
    protected V mView;
    protected Reference<T> mActivityRef;
    protected T mActivity;


    public BasePresenter(V view, T activity) {
        attachView(view);
        attachActivity(activity);
        setListener(activity);
    }

    /**
     * 设置生命周期监听
     *
     * @author ZhongDaFeng
     */
    private void setListener(T activity) {
        if (getActivity() != null) {
            if (activity instanceof BaseActivity) {
                ((BaseActivity) getActivity()).setOnLifeCycleListener(this);
            } else if (activity instanceof BaseFragmentActivity) {
                ((BaseFragmentActivity) getActivity()).setOnLifeCycleListener(this);
            }
        }
    }

    /**
     * 关联
     *
     * @param view
     */
    private void attachView(V view) {
        mViewRef = new WeakReference<V>(view);
        mView = mViewRef.get();
    }

    /**
     * 关联
     *
     * @param activity
     */
    private void attachActivity(T activity) {
        mActivityRef = new WeakReference<T>(activity);
        mActivity = mActivityRef.get();
    }

    /**
     * 销毁
     */
    private void detachView() {
        if (isViewAttached()) {
            mViewRef.clear();
            mViewRef = null;
        }
    }

    /**
     * 销毁
     */
    private void detachActivity() {
        if (isActivityAttached()) {
            mActivityRef.clear();
            mActivityRef = null;
        }
    }

    /**
     * 获取
     *
     * @return
     */
    public V getView() {
        if (mViewRef == null) {
            return null;
        }
        return mViewRef.get();
    }

    /**
     * 获取
     *
     * @return
     */
    public T getActivity() {
        if (mActivityRef == null) {
            return null;
        }
        return mActivityRef.get();
    }

    /**
     * 是否已经关联
     *
     * @return
     */
    public boolean isViewAttached() {
        return mViewRef != null && mViewRef.get() != null;
    }

    /**
     * 是否已经关联
     *
     * @return
     */
    public boolean isActivityAttached() {
        return mActivityRef != null && mActivityRef.get() != null;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {

    }

    @Override
    public void onStart() {

    }

    @Override
    public void onRestart() {

    }

    @Override
    public void onResume() {

    }

    @Override
    public void onPause() {

    }

    @Override
    public void onStop() {

    }

    @Override
    public void onDestroy() {
        detachView();
        detachActivity();
    }
}

//presenter 继承上面的BasePresenter 
 if (getView() != null&&getActivity()!=null){
       if(!quanCryBean.isError())
                getView().loadCry(quanCryBean.getQuan_category()); 
           else
                getView().loadCryFail(quanCryBean.getError_msg());                   
}