Android——MVP架構

MVC和MVP的區別

MVC（Model View Controller),Model就是模型、View是視圖、Controller就是控制器,（對應於Activity）。
Model在MVC架構中是真正的業務邏輯實現層，所以Model實際上是Business Model(業務模型)。而Controller主要負責把View的請求轉發給Model,再把Model處理結果通知給View，Controller是用來解耦View和Model的，目的就是實現UI和邏輯的分離。
在實際的程序中，數據綁定、事件的處理都是在Activity中，導致Activity很複雜。此外，MVC的設計思想是從Model出發，沒有考慮到View端的複雜性，這樣的結果就是Model難以負荷複雜多變的View端。
MVP（Model View Presenter）,其中presenter完全將Model和View進行分離，主要的邏輯程序在Presenter中實現。而且Presenter與具體的View沒有直接的關聯，而是通過定義好的接口進行交互，從而在保證Presenter的不變，即重用。在MVP中可以修改視圖而不影響模型，所有的交互都發生在presenter內部。
MVP相對於MVC的好處：MVC中允許View和Model交互，而在MVC中兩者之間的交互時通過presenter完成的。

通過例子學習：
佈局：
activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context=".MainActivity"
    android:orientation="vertical">
   <RelativeLayout
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       >
       <TextView
           android:id="@+id/name_text"
           android:layout_width="wrap_content"
           android:layout_height="wrap_content"
           android:layout_centerVertical="true"
           android:text="用戶名" />
       <EditText
           android:id="@+id/name_edit"
           android:layout_width="match_parent"
           android:layout_height="wrap_content"
           android:layout_toRightOf="@id/name_text"/>
   </RelativeLayout>
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        >
        <TextView
            android:id="@+id/password_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_centerVertical="true"
            android:text=" 密碼   " />
        <EditText
            android:id="@+id/password_edit"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_toRightOf="@id/password_text"/>
    </RelativeLayout>
    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        >
        <Button
            android:id="@+id/login_button"
            android:layout_width="120dp"
            android:layout_height="wrap_content"
            android:text="Login"
            android:layout_alignParentTop="true"
            android:layout_alignParentStart="true"
            android:layout_marginStart="39dp" />
        <Button
            android:id="@+id/clear_button"
            android:layout_width="120dp"
            android:layout_height="wrap_content"
            android:text="Clear"
            android:layout_alignParentTop="true"
            android:layout_alignParentEnd="true"
            android:layout_marginEnd="34dp"/>
    </RelativeLayout>
    <ProgressBar
        android:id="@+id/progressBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

Model:
User

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

public interface IUserBiz {
    public void login(String userName,String password,OnLoginListener loginListener);
}

OnLoginListener:

public interface OnLoginListener {
    void loginSuccess(User user);

    void loginFailed();
}

UserBiz

public class UserBiz implements IUserBiz {
    @Override
    public void login(final String userName, final String password, final OnLoginListener loginListener) {
        new Thread(new Runnable() {
            @Override
            public void run() {
                if("lcy".equals(userName)&&"123".equals(password)){
                    User user=new User();
                    user.setPassword(password);
                    user.setUserName(userName);
                    loginListener.loginSuccess(user);
                }else{
                    loginListener.loginFailed();
                }
            }
        }).start();
    }
}

View:
IUserView

public interface IUserLoginView {

    String getUserName();

    String getPassWord();

    void clearUserName();

    void clearPassWord();

    void showLoading();

    void hideLoading();

    void toMainActivity(User user);

    void showFailedError();

}

MainActivity

public class MainActivity extends AppCompatActivity implements IUserLoginView{

    private EditText nameText;
    private EditText passwordText;
    private Button loginButton;
    private Button clearButton;
    private ProgressBar progressBar;
    private UserLoginPresenter userLoginPresenter=new UserLoginPresenter(this);

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

    void initViews(){
        nameText= (EditText) findViewById(R.id.name_edit);
        passwordText=(EditText)findViewById(R.id.password_edit);
        loginButton=(Button)findViewById(R.id.login_button);
        clearButton=(Button)findViewById(R.id.clear_button);
        progressBar=(ProgressBar)findViewById(R.id.progressBar);
        loginButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                 userLoginPresenter.login();
            }
        });
        clearButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                 userLoginPresenter.clear();
            }
        });
    }

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

    @Override
    public String getPassWord() {
        return passwordText.getText().toString();
    }

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

    @Override
    public void clearPassWord() {
        passwordText.setText("");
    }

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

    @Override
    public void hideLoading() {
       progressBar.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();
    }
}

Presenter

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

    public UserLoginPresenter(IUserLoginView userLoginView){
        this.userLoginView=userLoginView;
        this.userBiz=new UserBiz();
    }

    public void login(){
        userLoginView.showLoading();
        userBiz.login(userLoginView.getUserName(), userLoginView.getPassWord(), new OnLoginListener() {
            @Override
            public void loginSuccess(final User user) {
                mHandler.post(new Runnable() {
                    @Override
                    public void run() {
                        userLoginView.toMainActivity(user);
                        userLoginView.hideLoading();
                    }
                });
            }

            @Override
            public void loginFailed() {
                   mHandler.post(new Runnable() {
                       @Override
                       public void run() {
                           userLoginView.showFailedError();
                           userLoginView.hideLoading();
                       }
                   });
            }
        });
    }
    public void clear(){
        userLoginView.clearPassWord();
        userLoginView.clearUserName();
    }
}

參考：http://www.cnblogs.com/JustRun1983/p/3727560.html
http://blog.csdn.net/lmj623565791/article/details/46596109