1.MVP介绍

在Android项目中，Activity和Fragment占据了大部分的开发工作。如果有一种设计模式（或者说代码结构）专门是为优化Activity和Fragment的代码而产生的，你说这种模式重要不？这就是MVP设计模式。

按照MVC的分层，Activity和Fragment（后面只说Activity）应该属于View层，用于展示UI界面，以及接收用户的输入，此外还要承担一些生命周期的工作。Activity是在Android开发中充当非常重要的角色，特别是TA的生命周期的功能，所以开发的时候我们经常把一些业务逻辑直接写在Activity里面，这非常直观方便，代价就是Activity会越来越臃肿，超过1000行代码是常有的事，而且如果是一些可以通用的业务逻辑（比如用户登录），写在具体的Activity里就意味着这个逻辑不能复用了。如果有进行代码重构经验的人，看到1000+行的类肯定会有所顾虑。因此，Activity不仅承担了View的角色，还承担了一部分的Controller角色，这样一来V和C就耦合在一起了，虽然这样写方便，但是如果业务调整的话，要维护起来就难了，而且在一个臃肿的Activity类查找业务逻辑的代码也会非常蛋疼，所以看起来有必要在Activity中，把View和Controller抽离开来，而这就是MVP模式的工作了。

MVP模式的核心思想：

MVP把Activity中的UI逻辑抽象成View接口，把业务逻辑抽象成Presenter接口，Model类还是原来的Model。

这就是MVP模式，现在这样的话，Activity的工作的简单了，只用来响应生命周期，其他工作都丢到Presenter中去完成。从上图可以看出，Presenter是Model和View之间的桥梁，为了让结构变得更加简单，View并不能直接对Model进行操作，这也是MVP与MVC最大的不同之处。

2.与mvc区别

3.Rxjava+Retrofit+Mvp的在项目中得使用

1）项目结构如下

2）添加依赖

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {
        exclude group: 'com.android.support', module: 'support-annotations'    })    compile 'com.android.support:appcompat-v7:25.3.0'
    compile 'io.reactivex:rxandroid:1.2.0'
    compile 'com.squareup.retrofit2:adapter-rxjava:2.1.0'
    compile 'com.squareup.retrofit2:converter-gson:2.1.0'
    compile 'com.squareup.retrofit2:retrofit:2.1.0'    testCompile 'junit:junit:4.12'}

3）api包内容

public interface APIManagerService {    @GET("/weather/index")
    Observable<WeatherData> getWeatherData(@Query("format") String format, @Query("cityname") String cityname, @Query("key") String key) ;}

public class APIManager {    private static final String ENDPOINT = "http://v.juhe.cn";    private static final Retrofit sRetrofit = new Retrofit .Builder()
            .baseUrl(ENDPOINT)
            .addConverterFactory(GsonConverterFactory.create())
            .addCallAdapterFactory(RxJavaCallAdapterFactory.create()) // 使用RxJava作为回调适配器            .build();    private static final APIManagerService apiManager = sRetrofit.create(APIManagerService.class);    /**     * 获取天气数据     * @param city     * @return     */    public static Observable<WeatherData> getWeatherData(String format, String city) {        return apiManager.getWeatherData(format,city,"ad1d20bebafe0668502c8eea5ddd0333");    }

}

4）创建bean对象

public class WeatherData {    private String resultcode;    private String reason;      private ResultEntity result;    private int error_code;    public void setResultcode(String resultcode) {        this.resultcode = resultcode;    }    public void setReason(String reason) {        this.reason = reason;    }    public void setResult(ResultEntity result) {        this.result = result;    }    public void setError_code(int error_code) {        this.error_code = error_code;    }    public String getResultcode() {        return resultcode;    }    public String getReason() {        return reason;    }    public ResultEntity getResult() {        return result;    }    public int getError_code() {        return error_code;    }    public static class ResultEntity {         private SkEntity sk;               private TodayEntity today;        private List<FutureEntity> future;        public void setSk(SkEntity sk) {            this.sk = sk;        }        public void setToday(TodayEntity today) {            this.today = today;        }        public void setFuture(List<FutureEntity> future) {            this.future = future;        }        public SkEntity getSk() {            return sk;        }        public TodayEntity getToday() {            return today;        }        public List<FutureEntity> getFuture() {            return future;        }        public static class SkEntity {            private String temp;            private String wind_direction;            private String wind_strength;            private String humidity;            private String time;            public void setTemp(String temp) {                this.temp = temp;            }            public void setWind_direction(String wind_direction) {                this.wind_direction = wind_direction;            }            public void setWind_strength(String wind_strength) {                this.wind_strength = wind_strength;            }            public void setHumidity(String humidity) {                this.humidity = humidity;            }            public void setTime(String time) {                this.time = time;            }            public String getTemp() {                return temp;            }            public String getWind_direction() {                return wind_direction;            }            public String getWind_strength() {                return wind_strength;            }            public String getHumidity() {                return humidity;            }            public String getTime() {                return time;            }            @Override            public String toString() {                return "SkEntity{" +                        "temp='" + temp + '\'' +                        ", wind_direction='" + wind_direction + '\'' +                        ", wind_strength='" + wind_strength + '\'' +                        ", humidity='" + humidity + '\'' +                        ", time='" + time + '\'' +                        '}';            }
        }        public static class TodayEntity {            @Override            public String toString() {                return "TodayEntity{" +                        "temperature='" + temperature + '\'' +                        ", weather='" + weather + '\'' +                        ", weather_id=" + weather_id +                        ", wind='" + wind + '\'' +                        ", week='" + week + '\'' +                        ", city='" + city + '\'' +                        ", date_y='" + date_y + '\'' +                        ", dressing_index='" + dressing_index + '\'' +                        ", dressing_advice='" + dressing_advice + '\'' +                        ", uv_index='" + uv_index + '\'' +                        ", comfort_index='" + comfort_index + '\'' +                        ", wash_index='" + wash_index + '\'' +                        ", travel_index='" + travel_index + '\'' +                        ", exercise_index='" + exercise_index + '\'' +                        ", drying_index='" + drying_index + '\'' +                        '}';            }            private String temperature;            private String weather;                   private WeatherIdEntity weather_id;            private String wind;            private String week;            private String city;            private String date_y;            private String dressing_index;            private String dressing_advice;            private String uv_index;            private String comfort_index;            private String wash_index;            private String travel_index;            private String exercise_index;            private String drying_index;            public void setTemperature(String temperature) {                this.temperature = temperature;            }            public void setWeather(String weather) {                this.weather = weather;            }            public void setWeather_id(WeatherIdEntity weather_id) {                this.weather_id = weather_id;            }            public void setWind(String wind) {                this.wind = wind;            }            public void setWeek(String week) {                this.week = week;            }            public void setCity(String city) {                this.city = city;            }            public void setDate_y(String date_y) {                this.date_y = date_y;            }            public void setDressing_index(String dressing_index) {                this.dressing_index = dressing_index;            }            public void setDressing_advice(String dressing_advice) {                this.dressing_advice = dressing_advice;            }            public void setUv_index(String uv_index) {                this.uv_index = uv_index;            }            public void setComfort_index(String comfort_index) {                this.comfort_index = comfort_index;            }            public void setWash_index(String wash_index) {                this.wash_index = wash_index;            }            public void setTravel_index(String travel_index) {                this.travel_index = travel_index;            }            public void setExercise_index(String exercise_index) {                this.exercise_index = exercise_index;            }            public void setDrying_index(String drying_index) {                this.drying_index = drying_index;            }            public String getTemperature() {                return temperature;            }            public String getWeather() {                return weather;            }            public WeatherIdEntity getWeather_id() {                return weather_id;            }            public String getWind() {                return wind;            }            public String getWeek() {                return week;            }            public String getCity() {                return city;            }            public String getDate_y() {                return date_y;            }            public String getDressing_index() {                return dressing_index;            }            public String getDressing_advice() {                return dressing_advice;            }            public String getUv_index() {                return uv_index;            }            public String getComfort_index() {                return comfort_index;            }            public String getWash_index() {                return wash_index;            }            public String getTravel_index() {                return travel_index;            }            public String getExercise_index() {                return exercise_index;            }            public String getDrying_index() {                return drying_index;            }            public static class WeatherIdEntity {                private String fa;                private String fb;                public void setFa(String fa) {                    this.fa = fa;                }                public void setFb(String fb) {                    this.fb = fb;                }                public String getFa() {                    return fa;                }                public String getFb() {                    return fb;                }
            }
        }        public static class FutureEntity {            private String temperature;            private String weather;            /**             * fa : 01             * fb : 01             */            private WeatherIdEntity weather_id;            private String wind;            private String week;            private String date;            public void setTemperature(String temperature) {                this.temperature = temperature;            }            public void setWeather(String weather) {                this.weather = weather;            }            public void setWeather_id(WeatherIdEntity weather_id) {                this.weather_id = weather_id;            }            public void setWind(String wind) {                this.wind = wind;            }            public void setWeek(String week) {                this.week = week;            }            public void setDate(String date) {                this.date = date;            }            public String getTemperature() {                return temperature;            }            public String getWeather() {                return weather;            }            public WeatherIdEntity getWeather_id() {                return weather_id;            }            public String getWind() {                return wind;            }            public String getWeek() {                return week;            }            public String getDate() {                return date;            }            public static class WeatherIdEntity {                private String fa;                private String fb;                public void setFa(String fa) {                    this.fa = fa;                }                public void setFb(String fb) {                    this.fb = fb;                }                public String getFa() {                    return fa;                }                public String getFb() {                    return fb;                }                @Override                public String toString() {                    return "WeatherIdEntity{" +                            "fa='" + fa + '\'' +                            ", fb='" + fb + '\'' +                            '}';                }
            }            @Override            public String toString() {                return "FutureEntity{" +                        "temperature='" + temperature + '\'' +                        ", weather='" + weather + '\'' +                        ", weather_id=" + weather_id +                        ", wind='" + wind + '\'' +                        ", week='" + week + '\'' +                        ", date='" + date + '\'' +                        '}';            }
        }        @Override        public String toString() {            return "ResultEntity{" +                    "sk=" + sk +                    ", today=" + today +                    ", future=" + future +                    '}';        }
    }    @Override    public String toString() {        return "WeatherData{" +                "resultcode='" + resultcode + '\'' +                ", reason='" + reason + '\'' +                ", result=" + result +                ", error_code=" + error_code +                '}';    }

5）model层

public interface WeatherModel {
    Subscription getWeatherData(String format, String city);}

public class WeatherModelImp implements WeatherModel {    private WeatherOnListener mWeatherOnListener;    public WeatherModelImp(WeatherOnListener mWeatherOnListener) {        this.mWeatherOnListener = mWeatherOnListener;    }    @Override    public Subscription getWeatherData(String format, String city) {        //com.example.admin.rxretrofitmvp.api.APIManager        Observable<WeatherData> request = com.example.admin.rxretrofitmvp.api.APIManager.getWeatherData(format, city).cache();           Subscription sub = request.subscribeOn(Schedulers.io())
                  .observeOn(AndroidSchedulers.mainThread())
                    .subscribe(new Action1<WeatherData>() {                        @Override                        public void call(WeatherData weatherData) {                            mWeatherOnListener.onSuccess(weatherData);                        }
                    }, new Action1<Throwable>() {                        @Override                        public void call(Throwable throwable) {                           mWeatherOnListener.onFailure(throwable);                       }
                   });           return sub;    }

6）Present层

public class BasePesenter {    protected CompositeSubscription mCompositeSubscription;    //RXjava取消注册，以避免内存泄露    public void onUnsubscribe() {        if (mCompositeSubscription != null && mCompositeSubscription.hasSubscriptions()) {            mCompositeSubscription.unsubscribe();        }
    }    //RXjava注册    public void addSubscription(Subscription subscriber) {        if (mCompositeSubscription == null) {            mCompositeSubscription = new CompositeSubscription();        }        mCompositeSubscription.add(subscriber);    }
}

public abstract class WeatherPresenter extends BasePesenter {    public abstract void getWeatherData(String format, String city);}

public class WeatherPresenterImp extends WeatherPresenter implements WeatherOnListener{    /**     * WeatherModel和WeatherView都是通过接口来实现，这就Java设计原则中依赖倒置原则使用     */    private WeatherModel mWeatherModel;    private WeatherView mWeatherView;    public WeatherPresenterImp( WeatherView mWeatherView) {        this.mWeatherModel = new WeatherModelImp(this);        this.mWeatherView = mWeatherView;    }    @Override    public void getWeatherData(String format, String city) {        mWeatherView.showProgress();        addSubscription(mWeatherModel.getWeatherData(format,city));    }    @Override    public void onSuccess(WeatherData s) {        mWeatherView.loadWeather(s);        mWeatherView.hideProgress();        Log.d("-------", "onSuccess() called with: " + "s = [" + s.toString() + "]");    }    @Override    public void onFailure(Throwable e) {        mWeatherView.hideProgress();        Log.d("-------", "onFailure" + e.getMessage());    }
}

7）view层

public interface WeatherView {    void showProgress();    void hideProgress();    void loadWeather(WeatherData weatherData);}

8）监听器

public interface WeatherOnListener {    void onSuccess(WeatherData s);    void onFailure(Throwable e);}

9）LodingHelper

public class LoadingUIHelper {    private static Dialog dialog;    public static void showDialogForLoading(final Context context, String tipContext){        final AlertDialog.Builder builder = new AlertDialog.Builder(context);        dialog = builder.create();        builder.setTitle("");        builder.setMessage(tipContext);        builder.setIcon(R.mipmap.ic_launcher);        builder.setNegativeButton("取消",new DialogInterface.OnClickListener(){            @Override            public void onClick(DialogInterface dialogInterface, int i) {                dialog.dismiss();            }
        });        builder.setPositiveButton("確定",new DialogInterface.OnClickListener(){            @Override            public void onClick(DialogInterface dialogInterface, int i) {

            }
        });        builder.show();    }    public static void hideDialogForLoading(){        if(dialog != null){            dialog.dismiss();        }
    }
}

10）在Activity中处理

public class MainActivity extends AppCompatActivity implements WeatherView{    private WeatherPresenterImp mWeatherPresenter;    private TextView textView1;    private TextView textView2;    private TextView textView3;    private TextView textView4;    private TextView textView5;    private TextView textView6;    private TextView textView7;    private TextView textView8;    private TextView textView9;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        mWeatherPresenter = new WeatherPresenterImp(this);        mWeatherPresenter.getWeatherData("2", "苏州");        textView1 = (TextView) findViewById(R.id.textView1);        textView2 = (TextView) findViewById(R.id.textView2);        textView3 = (TextView) findViewById(R.id.textView3);        textView4 = (TextView) findViewById(R.id.textView4);        textView5 = (TextView) findViewById(R.id.textView5);        textView6 = (TextView) findViewById(R.id.textView6);        textView7 = (TextView) findViewById(R.id.textView7);        textView8 = (TextView) findViewById(R.id.textView8);        textView9 = (TextView) findViewById(R.id.textView9);    }    @Override    public void showProgress() {
        LoadingUIHelper.showDialogForLoading(this,"获取数据");    }    @Override    public void hideProgress() {
        LoadingUIHelper.hideDialogForLoading();        Toast.makeText(this,"服务器异常",Toast.LENGTH_SHORT).show();        mWeatherPresenter.onUnsubscribe();    }    @Override    public void loadWeather(WeatherData weatherData) {
        Log.d("weatherData", "weatherData==" + weatherData.toString());        textView1.setText("城市："+weatherData.getResult().getToday().getCity());        textView2.setText("日期："+weatherData.getResult().getToday().getWeek());        textView3.setText("今日温度："+weatherData.getResult().getToday().getTemperature());      //  textView4.setText("天气标识：" +WeatherIDUtils.transfer(weatherData.getResult().getToday().getWeather_id().getFa()));        textView5.setText("穿衣指数：" + weatherData.getResult().getToday().getDressing_advice());        textView6.setText("干燥指数："+weatherData.getResult().getToday().getDressing_index());        textView7.setText("紫外线强度："+weatherData.getResult().getToday().getUv_index());        textView8.setText("穿衣建议："+weatherData.getResult().getToday().getDressing_advice());        textView9.setText("旅游指数："+weatherData.getResult().getToday().getTravel_index());    }    @Override    protected void onDestroy() {        super.onDestroy();        //取消注册        mWeatherPresenter.onUnsubscribe();    }
}

原文链接：http://www.apkbus.com/blog-896840-64732.html