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鸿蒙开发MVVM+Retrofit+OkHttp+RxJava

2021-06-11  本文已影响0人  CHN_Liao

HarmonyMVVMHttp

刚接触Harmony开发2天!不得不吐槽一下,“远程真机调试”真的好难用还限时,日志还经常不打印(我本以为是Log问题,换了System.out.print也一样,哈哈),经常编译时候卡住,“Attach Debugger to Process”无法使用。开发的好吃力啊!但依然看好鸿蒙OS,拭目以待!

项目地址:https://gitee.com/Liao8180/harmony-mvvmhttp

简介

本项目主要“鸿蒙化”了部分android代码,过去使用MVVM爱不释手,来到鸿蒙后发现没有ViewModel和livedata,又不想用MVP,就试着照搬Android吧!搬完MVVM后,又想在鸿蒙里玩玩Retrofit+OkHttp+RxJava,查了查好像没有鸿蒙化的RxAndroid(项目里我以RxHarmony命名),于是也搬过来吧!搬着搬着发现鸿蒙居然能直接在主线程进行Http请求操作...这个问题没深究,继续搬代码!

温馨提示

本项目仅供参考,不建议直接丢进正式项目开发,如有bug概不负责哈!不熟悉的MVVM的,上百度,这里不做教学,而且我也不懂教(对,就是菜)!

1.MVVM

1.1 ViewModel和LiveData

因为鸿蒙暂时没有提供ViewModel和LiveData的功能,library中直接把Android的ViewModel和LiveData搬过来了。库中的HarmonyViewModel 相对于 AndroidViewModel。

public class HarmonyViewModel extends ViewModel{
    private AbilityPackage mApplication;

    public HarmonyViewModel(@NonNull AbilityPackage mApplication) {
        this.mApplication = mApplication;
    }

    @SuppressWarnings({"TypeParameterUnusedInFormals", "unchecked"})
    @NonNull
    public <T extends AbilityPackage> T getApplication() {
        return (T) mApplication;
    }

    @Override
    protected void onCleared() {
        super.onCleared();
    }
}

1.2 ComponentAbility和ComponentAbilitySlice

抽象类ComponentAbility和ComponentAbilitySlice相继继承了Ability和AbilitySlice。主要实现ViewModelStoreOwner接口中getViewModelStore()方法并且绑定生命周期(可参考Android中的ComponentActivity)。所以后续需使用MVVM的话,需使用ComponentAbilitySlice 或 ComponentAbility 。

public abstract class ComponentAbilitySlice extends AbilitySlice implements ViewModelStoreOwner {
    private ViewModelStore mViewModelStore;

    @Override
    protected void onStart(Intent intent) {
        super.onStart(intent);

        getLifecycle().addObserver(new LifecycleStateObserver() {
            @Override
            public void onStateChanged(Lifecycle.Event event, Intent intent) {
                if (event == Lifecycle.Event.ON_STOP) {
                    getViewModelStore().clear();
                }
            }
        });
    }

    @Override
    public ViewModelStore getViewModelStore() {
        if (getAbility().getAbilityPackage() == null) {
            throw new IllegalStateException("Your ability is not yet attached to the "
                    + "AbilityPackage instance. You can't request ViewModel before onStart call.");
        }

        if (mViewModelStore == null) {
            mViewModelStore = new ViewModelStore();
        }
        return mViewModelStore;
    }
}
public abstract class ComponentAbility extends Ability implements ViewModelStoreOwner {

    private ViewModelStore mViewModelStore;

    @Override
    protected void onStart(Intent intent) {
        super.onStart(intent);

        getLifecycle().addObserver(new LifecycleStateObserver() {
            @Override
            public void onStateChanged(Lifecycle.Event event, Intent intent) {
                if (event == Lifecycle.Event.ON_STOP) {
                    getViewModelStore().clear();
                }
            }
        });
    }

    @Override
    public ViewModelStore getViewModelStore() {
        if (getAbilityPackage() == null) {
            throw new IllegalStateException("Your ability is not yet attached to the "
                    + "AbilityPackage instance. You can't request ViewModel before onStart call.");
        }

        if (mViewModelStore == null) {
            mViewModelStore = new ViewModelStore();
        }
        return mViewModelStore;
    }
}

可能会有同学问,为什么没有Fraction的啊?

如果需要Fraction的同学,也可以照葫芦画瓢的写一个ComponentFraction和ComponentFractionAbility。我为什么没写是因为“懒”!

1.3 项目中的BaseViewModel、BaseVMAbilitySlice和BaseVMAbility 抽象类

Base系列大家应该都懂,这里不做过多描述。大家可以根据各自需求丰富各自的Base。

1.3.1 BaseViewModel

此处BaseViewModel仅仅定义了ViewModelProvider工厂和提供创建ViewModelProvider工厂的方法。

public abstract class BaseViewModel extends HarmonyViewModel {
    protected String TAG = this.getClass().getSimpleName();

    public BaseViewModel(AbilityPackage mApplication) {
        super(mApplication);
    }

    public static <T extends BaseViewModel> ViewModelProvider.Factory createViewModelFactory(T viewModel) {
        return new ViewModelFactory(viewModel);
    }

    static class ViewModelFactory implements ViewModelProvider.Factory {
        BaseViewModel viewModel;
        public ViewModelFactory(BaseViewModel viewModel) {
            this.viewModel = viewModel;
        }

        @NonNull
        @Override
        public <T extends ViewModel> T create(@NonNull Class<T> modelClass) {
            return (T) viewModel;
        }
    }

    @Override
    protected void onCleared() {
        super.onCleared();
    }
}

1.3.2 BaseVMAbilitySlice和BaseVMAbility

BaseVMAbilitySlice和BaseVMAbility通过泛型和抽象方法实例化ViewModel和布局。

public abstract class BaseVMAbilitySlice<VM extends BaseViewModel> extends ComponentAbilitySlice {
    protected String TAG = this.getClass().getSimpleName();
    protected VM mViewModel;

    @SuppressWarnings("unchecked")
    @Override
    protected void onStart(Intent intent) {
        super.onStart(intent);
        super.setUIContent(getUIContent());
        VM vm = createViewModel();
        mViewModel = (VM) new ViewModelProvider(this,BaseViewModel.createViewModelFactory(vm)).get(vm.getClass());

        init(intent);
    }

    /**
     * 获取布局id
     * @return
     */
    protected abstract int getUIContent();

    /**
     * 获取ViewModel实例
     * @return
     */
    protected abstract VM createViewModel();

    /**
     * 初始化
     */
    protected abstract void init(Intent intent);
}

2. Retrofit+OkHttp+RxJava

这个我就不细说了,Android开发时候大家应该都知道有RxAndroid这玩意吧(io.reactivex.rxjava3:rxandroid),我这里仅仅把它鸿蒙化了而已,可参考library中的rx_harmony文件夹。具体实现差不多,只是RxAndroid封装了Handler的实现,鸿蒙这里我用鸿蒙的EventHandler。

具体实现如下:

Disposable disposable = HttpHelper.getApi().getTestData()
                .compose(RxScheduler.Flo_io_main())
                .subscribeWith(new CommonSubscriber<BaseResponse<List<TestDataBean>>>() {
//                    @Override
//                    protected void onStart() {
//                        super.onStart();
//                        //这里可以告知UI启动Loading弹框
//                    }

                    @Override
                    protected void onSuccess(@NonNull BaseResponse<List<TestDataBean>> listBaseResponse) {
                        //通过MutableLiveData将请求获取的数据传到Ability或AbilitySlice中刷新页面。
                        data.setValue(listBaseResponse.getData());
                    }

                    @Override
                    protected void onFail(String msg) {
                        //异常
                    }

                    @Override
                    protected void onFinish() {
                        //请求结束
                    }
                });

最后别忘了在onCleared()中处理disposable啊!

@Override
    protected void onCleared() {
        super.onCleared();
        //处理disposable
        if (disposable != null && !disposable.isDisposed()){
            disposable.dispose();
        }
    }

有同学会问,如果页面有N个请求那不是要判断N个disposable和dispose N个?这里大家可以根据自己项目情况实现抽象类BaseViewModel并加入以下变量和方法,并且在onCleared()处理unSubscribe():

private CompositeDisposable mCompositeDisposable;

/**
     * 结束所有disposable
     */
    public void unSubscribe() {
        if (mCompositeDisposable != null) {
            mCompositeDisposable.dispose();
        }
    }

    /**
     * 移除指定disposable
     * @param subscription
     */
    public void removeSubscribe(Disposable subscription) {
        if (subscription == null || mCompositeDisposable == null) {
            return;
        }

        mCompositeDisposable.remove(subscription);
    }

    /**
     * 添加disposable
     * @param subscription
     */
    public void addSubscribe(Disposable subscription) {
        if (mCompositeDisposable == null) {
            mCompositeDisposable = new CompositeDisposable();
        }
        mCompositeDisposable.add(subscription);
    }

    @Override
    protected void onCleared() {
        super.onCleared();
        unSubscribe();
    }

当然Disposable的处理方式还有很多种,大家可以百度查查。可能我个人原因,不太喜欢在base中做太多功能实现,如需要一般都会通过子类去实现。

好了,就到这,有问题可以留言,在我能力范围内尽力回复。88

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