Dagger2的MVP模式基本使用和实现

Dagger基本介绍

根据官网来说他就是一个快速的依赖注入框架,作用重点就是解耦和管理实例对象,MVP模式可以在MVP模式上进一步解耦

获取书名

Dagger2注解简单使用(以购物为例手机"User"和"Book")

直销店如小米手机销店user

public class User {
    private String name;

    @Inject  //标记产品对象,没有构造参数不需要Module
    public User(){ this.name = "Sir1";}

    public String getName(){return name;}
}

组装手机,有构造参数需要Module不能用@Inject

public class Book {
    private String name;

    public Book(String name){this.name = name;}

    public String getName() { return name;}
}

有些手机专卖店买手机,有组装的手机也有直销的手机这时

@Module  //表示这个是手机专卖店
public class TestModule {
    @Provides  //提供各种各样的组装机1
    Book provideBook(){return  new Book("book1"); }

    //@Provides  //提供各种各样的组装机2
   // Book provideXiaomi(){return  new Xiaomi("book2"); }
}

写好邮件地址

//@Component  //表示标记要购买的物品如上的User对象
@Component(modules = {TestModule.class}) //标记手机专卖店当然也标记直销店
public interface TestComponent {
    void inject(MainActivity activity);
}

用户地址确认

public class MainActivity extends AppCompatActivity {

    @Inject  //标记直销机User
    User mUser;

    @Inject //标记组装机Book
    Book mBook;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        TextView textView = findViewById(R.id.tv_1);
//确认收到货物获取手机对象mUser和mBook
        DaggerTestComponent.create().inject(this);
        textView.setText("用户名:"+mUser.getName()+"\n书    名:"+ mBook.getName());
    }
}

到此Dagger2简单使用完毕

Dagger2的MVP模式讲解

基本的目录结构

MVP基本概念

view层接受用户请求,将请求传给presenter,presenter获得请求将请求数据传给mode,mode层获取相关数据,就会将获得的数据通知presenter,presenter再通知view层更新数据,再通知用户
总的来说,mode层和view已经完全解耦,都是通过presenter建立起来,那么没有解耦的只能通过Dagger来实现 , 为mode与presenter ,view与presenter

那么presenter与view怎么实现通知的?

通过view层实现接口,再在presenter调用接口方法
接口如下

public interface IUserBookShowListener {
    void getUserBookSuccess(Book book);
    void getUserBookFailed(String book);
}

定义基类

public abstract class BasePresenter {
    protected WeakReference weakRefView;
    public void attachView(V view){
        weakRefView = new WeakReference(view);
    }

    public void detach() {
        if(isAttach()) {
            weakRefView.clear();
            weakRefView = null;
        }
    }
    public V obtainView(){
        return isAttach()?weakRefView.get():null;
    }

    protected boolean isAttach() {
        return weakRefView != null &&
                weakRefView.get() != null;
    }

    public abstract void onDestroy();
}

public abstract class BaseMVPActivity extends AppCompatActivity {

    private P mPresenter;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mPresenter = createPresenter();
        mPresenter.attachView(this);
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        if (mPresenter !=null){
            mPresenter.detach();
            mPresenter.onDestroy();
            mPresenter = null;
            System.gc();
        }
    }

    protected abstract P createPresenter();
}

view层代码

public class MainActivity extends BaseMVPActivity implements IUserBookShowListener{

    private TextView tv_1;
    private Button bt_1;
    private EditText mEt_1;
    @Inject //标记
    UserBookPresenter mUserBookPresenter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initView();
    }

    private void initView() {
        mEt_1 = findViewById(R.id.et_1);
        bt_1 = findViewById(R.id.bt_1);
        tv_1 = findViewById(R.id.tv_1);

        bt_1.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if (!TextUtils.isEmpty(mEt_1.getText())) {
                    String s = mEt_1.getText().toString();
                    try {
                        Integer integer = Integer.valueOf(s);
                        mUserBookPresenter.getUserBook(integer);
                    }catch (Exception e){
                        Toast.makeText(MainActivity.this, "请输入数字",
                                Toast.LENGTH_SHORT).show();
                    }
                }
            }
        });
    }
//实现接口
    @Override
    public void getUserBookSuccess(final Book book) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                tv_1.setText(book.getName());
            }
        });
    }
//实现接口
    @Override
    public void getUserBookFailed(final String book) {
        runOnUiThread(new Runnable() {
            @Override
            public void run() {
                tv_1.setText(book);
            }
        });
    }

//获取UserBookPresenter对象
    @Override
    public UserBookPresenter getPresenter() {
        DaggerUserBookComponet.builder().userBookModule(new UserBookModule(this)).build().inject(this);
        return mUserBookPresenter;
    }
}

UserBookPresenter的实现

public class UserBookPresenter extends BasePresenter {

    @Inject //标记注入对象
    UserBookMode mUserBookMode;
    private IUserBookShowListener iUserBookShowListener;

    public UserBookPresenter( Context iUserBookShowListener) {
        this.iUserBookShowListener = obtainView();
//确认获取对象mUserBookMode实例
        DaggerUserBookPresenterComponet.create().inject(this);
    }

    public void getUserBook(final int i) {
        mUserBookMode.getUserBook(i, new OnUserBookListener() {
            @Override
            public void getUserBookSuccess(Book book) {
                if (iUserBookShowListener==null){
                    return;
                }
                iUserBookShowListener.getUserBookSuccess(book);
            }

            @Override
            public void getUserBookFailed(String book) {
                if (iUserBookShowListener==null){
                    return;
                }
                iUserBookShowListener.getUserBookFailed(book);
            }
        });
    }

}

代码地址