基类:

在开发中有着很重要的地位,基类设计封装的好,不管是对app的性能,还是对开发的效率都有着很重要的作用

基类可以简单几个字概况,一个良好的父类.

结构:

不管你的app是多个acitivity,还是1个activity+n个fragment,还是多个acitivity多个fragment.

始终都是用的acitivity和fragment.

根据项目的不同,基类不可能完全相同,但很多还是可以通用的.

抽取:

既然是mvp,那么不管是acitivity还是fragment.都归于v 既然是v,那么就应该有相对应的presenter,view 那么基类应该有: BaseActivityView BaseFragmentView BaseView BasePresenter

具体代码:

BaseActivity

public abstract class BaseActivity<T extends BasePresenter> extends AppCompatActivity implements BaseActivityView { protected T mPresenter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); //创建Presenter mPresenter = initPresenter(); //类似fragment的与view进行绑定.拿到引用 mPresenter.onAttch(this); //初始化acitivity, onCreateActivity(savedInstanceState); //初始化Presenter mPresenter.onCreate(); } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); mPresenter.onSaveInstanceState(outState); } @Override protected void onDestroy() { mPresenter.onDestroy(); super.onDestroy(); } @Override public BaseActivity getActivity() { return this; } /** * 创建prensenter * @return <T extends BasePresenter> 必须是BasePresenter的子类 */ protected abstract T initPresenter(); /** * 子类必须实现,并初始化Activity,比如setContentView() */ protected abstract void onCreateActivity(Bundle savedInstanceState); @Override public void isNightMode(boolean isNight) { } }

BaseFragment

稍微复杂一点.

public abstract class BaseFragment<T extends BasePresenter> extends Fragment implements BaseFragmentView { protected T mPresenter; protected Context mContext;//activity的上下文对象 protected Bundle mBundle; @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); if (mBundle != null) { outState.putBundle("bundle", mBundle); } } /** * 绑定activity * * @param context */ @Override public void onAttach(Context context) { super.onAttach(context); mContext = context; } /** * 运行在onAttach之后 * 可以接受别人传递过来的参数,实例化对象. * * @param savedInstanceState */ @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); //获取bundle,并保存起来 if (savedInstanceState != null) { mBundle = savedInstanceState.getBundle("bundle"); } else { mBundle = getArguments() == null ? new Bundle() : getArguments(); } //创建presenter mPresenter = initPresenter(); } /** * 运行在onCreate之后 * 生成view视图 */ @Nullable @Override public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { return initView(inflater, container, savedInstanceState); } /** * 运行在onCreateView之后 * 加载数据 */ @Override public void onActivityCreated(@Nullable Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); //由于fragment生命周期比较复杂,所以Presenter在onCreateView创建视图之后再进行绑定,不然会报空指针异常 mPresenter.onAttch(this); //presenter进行初始化. mPresenter.onCreate(); } @Override public void onDestroyView() { mPresenter.onDestroy(); super.onDestroyView(); } /** * 跳转fragment * * @param tofragment */ @Override public void startFragment(Fragment tofragment) { startFragment(tofragment, null); } /** * @param tofragment 跳转的fragment * @param tag fragment的标签 */ @Override public void startFragment(Fragment tofragment, String tag) { FragmentTransaction fragmentTransaction = getFragmentManager().beginTransaction(); fragmentTransaction.hide(this).add(android.R.id.content, tofragment, tag); fragmentTransaction.addToBackStack(tag); fragmentTransaction.commitAllowingStateLoss(); } /** * 类似Activity的OnBackgress * fragment进行回退 */ public void onBack() { getFragmentManager().popBackStack(); } /** * 初始化Fragment应有的视图 * * @return */ public abstract View initView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState); /** * 创建prensenter * * @return <T extends BasePresenter> 必须是BasePresenter的子类 */ public abstract T initPresenter(); @Override public Context getContext() { return mContext; } @Override public Bundle getBundle() { return mBundle; } @Override public BaseFragment getFragment() { return this; } }

再看看BaseView

public interface BaseView { /** * 切换夜间模式 * @param isNight 是否切换为夜间模式 */ void isNightMode(boolean isNight); }

BaseView得想好做什么事,必须是你的项目里所有view都有的共性

不仅是acitivity和fragment,还有控件

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关键的BasePresenter来了

/** * @author jlanglang 2016/11/11 15:10 */ public abstract class BasePresenter<T extends BaseView> { protected T mView; /** * 绑定View */ public void onAttch(T view) { this.mView = view; } /** * 做初始化的操作,需要在view的视图初始化完成之后才能调用 */ public abstract void onCreate(); /** * 默认在view销毁的时候调用,解除绑定 *在view销毁前释放presenter中的对象,资源. */ public void onDestroy() { mView = null; } /** * 容易被回收掉时保存数据 */ public abstract void onSaveInstanceState(Bundle outState); }

看看Acitivity的使用:

//创建的时候写好泛型实现好抽象方法就行,多么简单. public class MainActivity extends BaseActivity<MainActivityPresenterImpl> implements MainActivityContract.View { @Override protected MainActivityPresenterImpl initPresenter() { return new MainActivityPresenterImpl(); } @Override protected void onCreateActivity(Bundle savedInstanceState) { setContentView(R.layout.activity_main); } }

最后是对应的MainActivityPresenterImpl

,MainActivityContract

public class MainActivityPresenterImpl extends BasePresenter<MainActivityContract.View> implements MainActivityContract.Presenter { @Override public void onCreate() { } @Override public void onSaveInstanceState(Bundle outState) { } } public class MainActivityContract { public interface View extends BaseActivityView { } public interface Presenter{ } public interface Model { } }

总结:

对于BasePresenter一开始我是写成接口形式的.

后来使用过程中,发现很麻烦,每次绑定View,释放View都需要重复造轮子. 仔细想想,写成抽象类更适合.

每个Presenter继承BasePresenter,实现Contract中的接口为其补充

最后会发现,view和presenter的结构一样.基类作为复用,接口作为补充.

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