首先介绍一下MVP。

MVP 全称：Model-View-Presenter ；MVP 是从经典的模式MVC演变而来，它们的基本思想有相通的地方：Controller/Presenter负责逻辑的处理，Model提供数据，View负责显示。

M：耗时操作

V：视图处理，与用户进行交互

P：逻辑处理

MVC和MVP的区别：

在MVC中，View是可以直接访问Model的，在MVP中View并不直接使用Model，它们之间的通信是通过Presenter (MVC中的Controller)来进行的，所有的交互都发生在Presenter内部，而在MVC中View会直接从Model中读取数据而不是通过 Controller。

MVP的理解图：

MVC:

使用MVP模式实现简单的登录功能

1、新建三个package ：view,model,presenter

2、首先新建一个bean类，用来封装对象

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

    private String username;
    private String password;
}

3、创建view和model的接口

Model的登录接口

public interface IUserMode {
    /**
     * 登录
     *
     * @param user
     * @return 约定返回"true"为登录成功，其他为登录失败的错误信息
     */
    String login(User user);
}

View的登录接口

public interface IUserView {
    /**
     * 登录成功
     */
    void onLoginSuccess();

    /**
     * 登录失败
     *
     * @param error
     */
    void onLoginFailed(String error);
}

4、创建Presenter

public class UserPresenter {
    private final IUserView userView;
    private final UserMode userMode;

    public UserPresenter(IUserView userView) {
        this.userView = userView;
        this.userMode = new UserMode();
    }

    /**
     * 登录
     *
     * @param user
     */
    public void login(final User user) {
        new Thread() {
            @Override
            public void run() {
                final String res = userMode.login(user);
                new Handler(Looper.getMainLooper()).post(new Runnable() {
                    @Override
                    public void run() {
                        if ("true".equals(res)) {
                            userView.onLoginSuccess();
                        } else {
                            userView.onLoginFailed(res);
                        }
                    }
                });
            }
        }.start();
    }
}

5、创建view和model的实现类

Model的登录实现类

public class UserMode implements IUserMode {
    @Override
    public String login(User user) {
        boolean networkError = false; //网络是否异常

        try {
            Thread.sleep(3000);//模拟网络连接
            if (networkError) {
                return "网络异常";
            } else if ("ethanco".equals(user.getUsername()) && "123456".equals(user.getPassword())) {
                return "true";
            } else {
                return "账号或密码错误";
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
            return e.getMessage();
        }
    }
}

View的登录实现 - Activity

public class MainActivity extends AppCompatActivity implements IUserView, View.OnClickListener {

    private UserPresenter userPresenter;
    private EditText etUserName;
    private EditText etPassword;
    private ProgressDialog loginProgreess;

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

        etUserName = (EditText) findViewById(R.id.et_userName);
        etPassword = (EditText) findViewById(R.id.et_password);
        findViewById(R.id.btn_login).setOnClickListener(this);
        userPresenter = new UserPresenter(this);
    }

    @Override
    public void onLoginSuccess() {
        loginProgreess.dismiss();
        Toast.makeText(getApplicationContext(), "登录成功", Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onLoginFailed(String error) {
        loginProgreess.dismiss();
        Toast.makeText(getApplicationContext(), "登录失败:" + error, Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onClick(View v) {
        String username = etUserName.getText().toString().trim();
        String password = etPassword.getText().toString().trim();

        if (TextUtils.isEmpty(username) || TextUtils.isEmpty(password)) {
            Toast.makeText(getApplicationContext(), "账号或密码不能为空", Toast.LENGTH_SHORT).show();
            return;
        }

        loginProgreess = ProgressDialog.show(this, "登录", "正在登录...");
        userPresenter.login(new User(username, password));
    }
}

效果图如下：

推荐链接：

http://blog.csdn.net/EthanCo/article/details/50177289