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一、MVC的优缺点

优点：便于理解，开发快速，一定程度隔离业务于UI的耦合度
缺点：业务复杂有可能导致Controller爆炸，不利于维护迭代。

二、Model层设计分析

登录界面的需求：Model层包含登录的数据（UserName\PassWord）以及网络请求。
登录逻辑接口

public interface UserLogicModel {

    void login(String account,String password,UserLoginListener userLoginListener);

}

登录成功或者失败回调的接口

public interface UserLoginListener {
    void LoginSuccess();

    void LogicFailed();
}

登录接口的实现

public class UserLoginModelImpl implements  UserLogicModel {

@Override
public void login(final String account, final String password, final UserLoginListener userLoginListener) {
      //这里是处理登陆的业务逻辑
    Log.d("logic","登录中");
    new Handler().postDelayed(new Runnable(){

        @Override
        public void run() {
            if("weiwei".equals(account) && "123".equals(password)) {
                userLoginListener.LoginSuccess();
            } else {
                userLoginListener.LogicFailed();
            }
        }
    },3000);
}
}

三、View层设计分析

UI界面的编写

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="16dp"
    android:paddingLeft="16dp"
    android:paddingRight="16dp"
    android:paddingTop="16dp"
    tools:context="mvc.allure.com.mvxproject.MainActivity">

<ImageView
    android:layout_marginTop="56dp"
    android:src="@mipmap/ic_launcher"
    android:layout_gravity="center_horizontal"
    android:layout_width="100dp"
    android:layout_height="100dp" />

<android.support.design.widget.TextInputLayout
    android:layout_marginTop="20dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <EditText
        android:id="@+id/edit_account"
        android:hint="用户名"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
    </android.support.design.widget.TextInputLayout>

<android.support.design.widget.TextInputLayout
    android:layout_marginTop="20dp"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <EditText
        android:id="@+id/edit_password"
        android:hint="密码"
        android:inputType="textPassword"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</android.support.design.widget.TextInputLayout>

<android.support.v7.widget.AppCompatButton
    android:text="登录"
    android:layout_marginTop="24dp"
    android:id="@+id/btn_login"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">>
</android.support.v7.widget.AppCompatButton>
<android.support.v7.widget.AppCompatButton
    android:text="清空"
    android:layout_marginTop="24dp"
    android:id="@+id/btn_delete"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">>
</android.support.v7.widget.AppCompatButton>
</LinearLayout>

三、Controller层设计分析

Controller作为Activity/Fragment的综合控制

public class MainActivity extends AppCompatActivity implements View.OnClickListener{
private EditText editAccount;
private EditText editPassWord;
private AppCompatButton btnLogin;
private AppCompatButton btnClear;
private UserLogicModel logicModel;

private ProgressDialog progressDialog;

private String account ="";
private String password ="";
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    logicModel = new UserLoginModelImpl();
    initView();
    initListener();
}

private void initListener() {
    btnLogin.setOnClickListener(this);
    btnClear.setOnClickListener(this);
}

private void initView() {
    progressDialog = new ProgressDialog(this);
    progressDialog.setMessage("login process,Watting...");
    progressDialog.setCancelable(false);
    editAccount = (EditText)findViewById(R.id.edit_account);
    editPassWord = (EditText)findViewById(R.id.edit_password);
    btnLogin = (AppCompatButton)findViewById(R.id.btn_login);
    btnClear = (AppCompatButton)findViewById(R.id.btn_delete);
}

@Override
public void onClick(View view) {
    switch(view.getId()) {
        case R.id.btn_login:
            account = editAccount.getText().toString();
            password = editPassWord.getText().toString();
             progressDialog.show();
            logicModel.login(account, password, new UserLoginListener() {
                @Override
                public void LoginSuccess() {
                    Log.i("aa","login success!!!");
                    Toast.makeText(MainActivity.this,"login success!!!",Toast.LENGTH_SHORT).show();
                    progressDialog.dismiss();
                }

                @Override
                public void LogicFailed() {
                   Log.i("aa","login fail!!!");
                    Toast.makeText(MainActivity.this,"login fail!!!",Toast.LENGTH_SHORT).show();
                    progressDialog.dismiss();
                }
            });
            break;
        case R.id.btn_delete:
            editAccount.setText("");
            editPassWord.setText("");
            break;
       }
   }
}

MVC适用于项目初期，业务不复杂的场景。设计架构的目的：为了后期程序的开发于维护，使程序模块化，做到模块内部的高聚合和模块与模块的低耦合。注意不能为了设计而设计，架构而架构，针对不同的项目的大小，时间维度等选取不同的架构设计。