Android MVC,MVP,MVVM模式入门——重构登陆注册功能

一  MVC模式：

M:model,业务逻辑

V:view,对应布局文件

C:Controllor,对应Activity

项目框架：

代码部分：

　　layout文件（适用于MVC和MVP两个Demo）：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <EditText
        android:id="@+id/edit_username"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:hint="username"/>

    <EditText
        android:id="@+id/edit_password"
        android:layout_width="match_parent"
        android:layout_height="50dp"
        android:inputType="textPassword"
        android:hint="password"/>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">

        <Button
            android:id="@+id/login"
            android:layout_marginLeft="10dp"
            android:layout_width="120dp"
            android:layout_height="50dp"
            android:text="Login"/>

        <Button
            android:id="@+id/clear"
            android:layout_width="120dp"
            android:layout_height="50dp"
            android:layout_marginLeft="100dp"
            android:text="Clear"/>

    </LinearLayout>

    <ProgressBar
        android:id="@+id/login_progressbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:visibility="invisible"
        />
</LinearLayout>

　　User类，定义成员对象：

package com.example.liang.userloginformvc.modle;

/**
 * Created by liang on 2016/8/22.
 */
public class User {
    private String username;
    private String password;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

　　OnLoginListener,j监听登陆状态:

package com.example.liang.userloginformvc.modle;

/**
 * Created by liang on 2016/8/22.
 */
public interface OnLoginListener {
    void loginSuccess(User user);
    void loginFailed();
}

　　UserBiz,登陆逻辑:

package com.example.liang.userloginformvc.modle;

/**
 * Created by liang on 2016/8/22.
 */
public class UserBiz {

    public void login(final String username,final String password,final OnLoginListener loginListener){
        new Thread(){
            @Override
            public void run() {
                try{
                    Thread.sleep(2000);
                }catch(InterruptedException e){
                    e.printStackTrace();
                }
                //模拟登陆
                if("lqy".equals(username)&&"123".equals(password)){
                    User user=new User();
                    user.setUsername(username);
                    user.setPassword(password);
                    loginListener.loginSuccess(user);
                }else{
                    loginListener.loginFailed();
                }
            }
        }.start();

    }
}

MVC模式总结：

　　首先从响应用户点击事件，到MainActivity，获取View中的数据再交给Model层处理，通过返回的数据，MainActivity再改变视图。

从MVC到MVP：由于View和Model之间的依赖还是太强，希望他们可以绝对独立的存在，慢慢的就演化出了MVP

二  MVP模式

M:业务逻辑与实体模型

V:负责View的绘制以及用户交互，对应Activity

P:负责完成View与Modle之间的交换

项目框架：

代码部分：

　　user:

package com.example.liang.userloginformvp.bean;

/**
 * Created by liang on 2016/8/22.
 */
public class User{
    private String username;
    private String password;

    public String getUsername() {
        return username;
    }

    public void setUsername(String username) {
        this.username = username;
    }

    public String getPassword() {
        return password;
    }

    public void setPassword(String password) {
        this.password = password;
    }
}

　　IUserBiz:

package com.example.liang.userloginformvp.biz;



/**
 * Created by liang on 2016/8/22.
 */
public interface IUserBiz{
    public void login(String username,String password,OnLoginListener onLoginListener);
}

　　OnLoginListener:

package com.example.liang.userloginformvp.biz;



/**
 * Created by liang on 2016/8/22.
 */
public interface IUserBiz{
    public void login(String username,String password,OnLoginListener onLoginListener);
}

　　UserBiz:

package com.example.liang.userloginformvp.biz;

import com.example.liang.userloginformvp.bean.User;

/**
 * Created by liang on 2016/8/22.
 */
public class UserBiz implements IUserBiz {
    //在这里重写IUserBiz中的方法
    @Override
    public void login(final String username, final String password, final OnLoginListener loginListener) {
        //注意，这里并没有new OnLoginListener的对象，所以也没有重写方法
        //要留在UserLoginPresenter中重写，并通过登陆的状态调用相应的视图
        new Thread(){
            @Override
            public void run() {
                try{
                    Thread.sleep(2000);
                }catch(InterruptedException e){
                    e.printStackTrace();
                }
                //模拟登陆成功
                if("lqy".equals(username)&&"123".equals(password)){
                    User user=new User();
                    user.setUsername(username);
                    user.setPassword(password);
                    loginListener.loginSuccess(user);
                }else{
                    loginListener.loginFailed();
                }
            }
        }.start();
    }
}

　　UserLoginPresenter:

public class UserLoginPresenter {
    private IUserBiz userBiz;
    private IUserLoginView userLoginView;
    private Handler mHandler = new Handler();

    public UserLoginPresenter(IUserLoginView userLoginView) {
        this.userLoginView = userLoginView;

        //给userBiz一个子类的空间，此时方法已经被重写,登陆逻辑已被判断
        this.userBiz = new UserBiz();
    }

    public void login() {
        userLoginView.showLoading();
        userBiz.login(userLoginView.getUserName(), userLoginView.getPassword(), new OnLoginListener() {
            @Override
            public void loginSuccess(final User user) {
                //需要在UI线程执行
                mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        userLoginView.toMainActivity(user);
                        userLoginView.hideLoading();
                    }
                });

            }

            @Override
            public void loginFailed() {
                //需要在UI线程执行
                mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        userLoginView.showFailedError();
                        userLoginView.hideLoading();
                    }
                });

            }
        });
    }

    public void clear() {
        userLoginView.clearUserName();
        userLoginView.clearPassword();
    }


}

　　IUserLoginPresenter:

package com.example.liang.userloginformvp.view;

import com.example.liang.userloginformvp.bean.User;

/**
 * Created by liang on 2016/8/22.
 */
public interface IUserLoginView {
    String getUserName();

    String getPassword();

    void clearUserName();

    void clearPassword();

    void showLoading();

    void hideLoading();

    void toMainActivity(User user);

    void showFailedError();
}

　　MainActivity:

package com.example.liang.userloginformvp;

import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast;

import com.example.liang.userloginformvp.bean.User;
import com.example.liang.userloginformvp.presenter.UserLoginPresenter;
import com.example.liang.userloginformvp.view.IUserLoginView;

public class MainActivity extends ActionBarActivity implements IUserLoginView{

    private EditText usernaem_edit,password_edit;
    private Button login_btn,clear_btn;
    private ProgressBar loading;

    private UserLoginPresenter userLoginPresenter=new UserLoginPresenter(this);

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

        initViews();
    }

    private void initViews(){
        usernaem_edit=(EditText)findViewById(R.id.edit_username);
        password_edit=(EditText)findViewById(R.id.edit_password);

        login_btn=(Button)findViewById(R.id.login);
        clear_btn=(Button)findViewById(R.id.clear);

        loading=(ProgressBar)findViewById(R.id.login_progressbar);
        loading.setVisibility(View.INVISIBLE);
        login_btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                userLoginPresenter.login();
            }
        });

        clear_btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                userLoginPresenter.clear();
            }
        });

    }

    @Override
    public String getUserName() {
        return usernaem_edit.getText().toString();
    }

    @Override
    public String getPassword() {
        return password_edit.getText().toString();
    }

    @Override
    public void clearUserName() {
        usernaem_edit.setText("");
    }

    @Override
    public void clearPassword() {
        password_edit.setText("");
    }

    @Override
    public void showLoading() {
        loading.setVisibility(View.VISIBLE);
    }

    @Override
    public void hideLoading() {
        loading.setVisibility(View.GONE);
    }

    @Override
    public void toMainActivity(User user) {
        Toast.makeText(this,user.getUsername()+" login success , to MainActivity",Toast.LENGTH_SHORT)
                .show();
    }

    @Override
    public void showFailedError() {
        Toast.makeText(this, "login failed", Toast.LENGTH_SHORT).show();
    }
}

MVP总结：Activity作为View加载视图并响应点击事件（直接想登陆），点击事件交由Presenter处理，Presenter将登陆逻辑交给Model处理，并根据model处理结果告诉View改返回什么试图。

------------------------------------分隔线

从MVP到MVVM中：至于MVVM基本上和MVP一模一样，感觉只是名字替换了一下。他的关键技术就是今天的主题(Data Binding)。View的变化可以自动的反应在ViewModel，ViewModel的数据变化也会自动反应到View上。这样开发者就不用处理接收事件和View更新的工作，框架已经帮你做好了。

三  MVVM模式

M:model,业务逻辑

V：加载视图，和layout通信，进行数据绑定与更新，对应Activity（由于代码是在太少，有时自带启动自己的方法）

VM：判断条件，逻辑实现

项目框架：

首先配置环境

加一句：

　　LoginViewModel

package com.example.liang.userloginformvvm.viewmodel;

import android.content.Context;
import android.databinding.ObservableField;
import android.databinding.ObservableInt;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;

import com.example.liang.userloginformvvm.modle.User;
import com.example.liang.userloginformvvm.view_activity.MainActivity;

/**
 * Created by liang on 2016/8/23.
 */
public class LoginViewModel implements ViewModel {
    private Context context;
    //用于数据刷新的便捷类型：ObservableField，ObservableInt····
    public ObservableField<String> loginMessage;
    public ObservableInt loginMessageVisibility;
    private String editTextUsernameValue = "";
    private String editTextPasswordValue = "";

    public LoginViewModel(Context context) {
        this.context = context;
        this.loginMessage = new ObservableField<>("");
        this.loginMessageVisibility = new ObservableInt(View.INVISIBLE);
    }

    //登陆，实际上这个方法是在layout文件中调用的

    public void loginAuthentication(View view) {
        if ((editTextUsernameValue.equals("lqy")) && (editTextPasswordValue.equals("123"))) {
            loginMessage.set("");
            loginMessageVisibility.set(View.INVISIBLE);
            User user = new User(editTextUsernameValue, editTextPasswordValue);
            context.startActivity(MainActivity.newIntent(context, user));
        } else if ((editTextUsernameValue.equals("")) || (editTextPasswordValue.equals(""))) {
            loginMessage.set("Username or Password can't be empty!");
            loginMessageVisibility.set(View.VISIBLE);
        } else {
            loginMessage.set("Username = lqy 
 Password = 123");
            loginMessageVisibility.set(View.VISIBLE);
        }
    }

    //观察Text变化的TextWatcher
    public TextWatcher getUsernameUpdate() {
        return new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                editTextUsernameValue = charSequence.toString();
            }

            @Override
            public void afterTextChanged(Editable editable) {

            }
        };
    }

    public TextWatcher getPasswordUpdate() {
        return new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
                editTextPasswordValue = charSequence.toString();
            }

            @Override
            public void afterTextChanged(Editable editable) {

            }
        };
    }


    @Override
    public void destroy() {

    }
}

　　MainViewModel:

package com.example.liang.userloginformvvm.viewmodel;

import android.content.Context;

import com.example.liang.userloginformvvm.modle.User;

/**
 * Created by liang on 2016/8/23.
 */
public class MainViewModel {
    private Context context;
    private User user;

    public MainViewModel(Context context, User user) {
        this.context = context;
        this.user = user;
    }

    public String getUsername(){
        return user.username;
    }
    public String getPassword(){
        return user.password;
    }
}

　　ViewModel:

package com.example.liang.userloginformvvm.viewmodel;

/**
 * Created by liang on 2016/8/23.
 */
public interface ViewModel {
    void destroy();
}

　　User:

package com.example.liang.userloginformvvm.modle;

import android.os.Parcel;
import android.os.Parcelable;

/**
 * Created by liang on 2016/8/23.
 */
//实现Parcelable接口，可以让类在网络或进程中传递
public class User implements Parcelable{
    public String username;
    public String password;

    public User(String username,String password){
        this.username=username;
        this.password=password;
    }

    public User(Parcel in) {
        username = in.readString();
        password = in.readString();
    }

    public static final Creator<User> CREATOR=new Creator<User>() {
        @Override
        public User createFromParcel(Parcel parcel) {
            return new User(parcel);
        }

        @Override
        public User[] newArray(int i) {
            return new User[i];
        }
    };

    @Override
    public int describeContents() {
        return 0;
    }

    @Override
    public void writeToParcel(Parcel parcel, int i) {
        parcel.writeString(this.username);
        parcel.writeString(this.password);
    }
}

　　

　　LoginActivity

package com.example.liang.userloginformvvm.view_activity;

import android.databinding.DataBindingUtil;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;


import com.example.liang.userloginformvvm.R;
import com.example.liang.userloginformvvm.databinding.ActivityLoginBinding;
import com.example.liang.userloginformvvm.viewmodel.LoginViewModel;

/**
 * Created by liang on 2016/8/23.
 */
public class LoginActivity extends AppCompatActivity{
    //当给布局指定格式之后会产生相应的Bing类，例如activity_login.xml会产生ActivityLoginBinding类
    ActivityLoginBinding loginBinding;
    LoginViewModel viewModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //指定布局，没有XXX.findViewById了
        loginBinding = DataBindingUtil.setContentView(this, R.layout.activity_login);

        viewModel=new LoginViewModel(this);
        loginBinding.setViewmodel(viewModel);
    }
}

　　MainActivity

package com.example.liang.userloginformvvm.view_activity;

import android.content.Context;
import android.content.Intent;
import android.databinding.DataBindingUtil;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import com.example.liang.userloginformvvm.R;
import com.example.liang.userloginformvvm.databinding.ActivityMainBinding;
import com.example.liang.userloginformvvm.modle.User;
import com.example.liang.userloginformvvm.viewmodel.MainViewModel;

/**
 * Created by liang on 2016/8/23.
 */
public class MainActivity extends AppCompatActivity{
    ActivityMainBinding activityMainBinding;
    MainViewModel mainViewModel;

    //传递数据的标志
    private static final String EXTRA_USER = "extra_user";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        activityMainBinding= DataBindingUtil.setContentView(this, R.layout.activity_main);


        User user=getIntent().getParcelableExtra(EXTRA_USER);
        
        mainViewModel=new MainViewModel(this,user);
        activityMainBinding.setMainviewmodel(mainViewModel);
    }

    //viewmodel唤醒这个Activity的方法
    public static Intent newIntent(Context context, User user){
        Intent intent = new Intent(context, MainActivity.class);
        intent.putExtra(EXTRA_USER,user);
        return intent;
    }
}

　　下面就是非常重要的layout文件了：

activity_mian.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools">

    <data>
        <variable
            name="viewmodel"
            type="com.example.liang.userloginformvvm.viewmodel.LoginViewModel">

        </variable>
    </data>
    <!--先要指定绑定的类-->
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".view_activity.LoginActivity">


        <TextView
            android:id="@+id/loginmessage"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@{viewmodel.loginMessage}"
            android:textAlignment="center"
            android:textColor="@color/colorAccent"
            android:layout_centerHorizontal="true"
            android:layout_marginTop="20dp"
            android:layout_marginBottom="20dp"/>

        <!--监听text的变化-->
        <EditText
            android:id="@+id/login_username"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:inputType="textPersonName"
            android:ems="10"
            android:layout_centerHorizontal="true"
            android:layout_below="@+id/loginmessage"
            android:hint="UserName"
            android:layout_marginBottom="10dp"
            app:addTextChangedListener="@{viewmodel.usernameUpdate}"/>

        <EditText
            android:id="@+id/login_password"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:inputType="textPassword"
            android:hint="Password"
            android:ems="10"
            android:layout_below="@id/login_username"
            android:layout_centerHorizontal="true"
            android:layout_marginBottom="10dp"
            app:addTextChangedListener="@{viewmodel.passwordUpdate}" />

        <Button
            android:layout_width="210dp"
            android:layout_height="wrap_content"
            android:text="LOGIN"
            android:layout_below="@id/login_password"
            android:layout_centerHorizontal="true"
            android:onClick="@{viewmodel.loginAuthentication}"/>

    </RelativeLayout>
</layout>

activity_login.xml

<?xml version="1.0" encoding="utf-8"?>
<layout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">
    <data>
        <variable
            name="mainviewmodel"
            type="com.example.liang.userloginformvvm.viewmodel.MainViewModel"></variable>
    </data>
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        tools:context=".view_activity.MainActivity">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:orientation="horizontal">
            <TextView
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:text="Welcome"
                android:layout_weight="1"/>

            <TextView
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="3"
                android:text="@{mainviewmodel.username}"/>
        </LinearLayout>


        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:orientation="horizontal">

            <TextView
            android:layout_width="0dp"
            android:layout_height="match_parent"
            android:text="Password is"
            android:layout_weight="1"/>

            <TextView
                android:layout_width="0dp"
                android:layout_height="match_parent"
                android:layout_weight="3"
                android:text="@{mainviewmodel.password}"/>
        </LinearLayout>
    </LinearLayout>

</layout>

MVVM总结：通过View加载布局，并通过布局调用ViewModel中的方法，VeiwModel可以通过调用后的结果决定启动什么视图，同时ViewModel保持和model的通信。

2016.8.24首次截稿 

有什么错误麻烦大家指出来，在线更新。 

参考资料：

鸿洋老师的博客： http://blog.csdn.net/lmj623565791/article/details/46596109

胡笛老师的微信推文

还有github上的资源

以及http://my.oschina.net/u/1175007/blog/613889