public class User{
    private String UserName;
    private String PassWord;
    public User(String UserName,String PassWord){
        this.PassWord = PassWord;
        this.UserName = UserName;
    }
    public User(){
    }
    public String getUserName() {
        return UserName;
    }
    public void setUserName(String userName) {
        UserName = userName;
    }
    public String getPassWord() {
        return PassWord;
    }
    public void setPassWord(String passWord) {
        PassWord = passWord;
    }
}

建立实体类接口

public interface IUser {
    boolean LoginAccount(String userName,String passWord);
}

实现实体类接口

public class exeLogin implements IUser {
    private User user;
    @Override
    public boolean LoginAccount(String userName,String passWord) {
        if (userName.equals( "admin" ) && passWord.equals( "123456" )){
            user = new User(  );
            user.setUserName( userName );
            user.setPassWord( passWord );
            return true;
        }
        return false;
    }
}

设置P层

public class LoginPresenter {
    private exeLogin exeLogin;
    private IMain iMain;
    public LoginPresenter(IMain iMain){
        this.iMain = iMain;
        exeLogin = new exeLogin();
    }
    public void Login(){
        String userName = iMain.getUserName();
        String passWord = iMain.getPassWord();
        boolean isSuccess = exeLogin.LoginAccount( userName,passWord  );
        iMain.Login( isSuccess );
    }
}

建立交互接口

public interface IMain {
    String getUserName();
    String getPassWord();
    void Login(Boolean isLoginSuccess);
}

数据绑定

public class MainActivity extends AppCompatActivity implements IMain{
    private EditText userName,passWord;
    private Button btnLogin;
    private Context context = null;
    private LoginPresenter loginPresenter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        setContentView( R.layout.activity_main );
        InitView();
        Listener();
    }
    private void InitView(){
        userName = findViewById( R.id.username );
        passWord = findViewById( R.id.password );
        btnLogin = findViewById( R.id.login );
        loginPresenter = new LoginPresenter( this );
        if (context == null){
            context = MainActivity.this;
        }
    }
    private void Listener(){
        btnLogin.setOnClickListener( new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                loginPresenter.Login();
                Log.d( "TAG","click success" );
            }
        } );
    }
    @Override
    public String getUserName() {
        return userName.getText().toString().trim();
    }
    @Override
    public String getPassWord() {
        return passWord.getText().toString().trim();
    }
    @Override
    public void Login(Boolean isLoginSuccess) {
        if (isLoginSuccess){
            Toast.makeText( MainActivity.this,"Success",Toast.LENGTH_SHORT ).show();
            Log.d( "TAG","Success" );
        }else {
            Toast.makeText( MainActivity.this,"Fail",Toast.LENGTH_SHORT ).show();
            Log.d( "TAG","Fail" );
        }
    }
}

MVVM

效果图

描述

Model层：

数据处理

View层

实体

ViewModel：

实现视图与数据的交互，将二者分离，实现解耦

代码解析

导入dataBinding

dataBinding {
            enabled = true
        }

实体类

public class User extends BaseObservable {
    public String mUserName;
    public String mPassWord;
    public User(){
    }
    public User(String mUserName,String mPassWord){
        this.mUserName = mUserName;
        this.mPassWord = mPassWord;
    }
    @Bindable
    public String getmUserName() {
        return mUserName;
    }
    /**
     * @param mUserName */
    public void setmUserName(String mUserName) {
        this.mUserName = mUserName;
        notifyPropertyChanged( BR.mUserName );
    }
    @Bindable
    public String getmPassWord() {
        return mPassWord;
    }
    /**
     * @param mPassWord */
    public void setmPassWord(String mPassWord) {
        this.mPassWord = mPassWord;
        notifyPropertyChanged( BR.mPassWord );
    }
}

添加 @Bindable，作为xml绑定字段

 @Bindable
    public String getmUserName() {
        return mUserName;
    }

BR是一个自动生成的类，大致内容为将每一个字段添加ID，通过notifyPropertyChanged实现数据更新

/**
     * @param mUserName */
    public void setmUserName(String mUserName) {
        this.mUserName = mUserName;
        notifyPropertyChanged( BR.mUserName );
    }

建立viewmodel

public class ViewModel {
    private ActivityMainBinding binding;
    public User user;
    public ViewModel(ActivityMainBinding binding,User user){
        this.binding = binding;
        this.user = user;
    }
    public void Login(View view){
        if (user.getmUserName().equals( "admin" ) && user.getmPassWord().equals( "123456" )){
            Log.d( "TAG","success" );
        }else {
            Log.d( "TAG","fail" );
        }
        Log.d( "TAG",user.getmUserName()+"" );
        Log.d( "TAG",user.getmPassWord()+"" );
    }
}

xml绑定数据

注意视图绑定数据层字段时，一个等于=符号产生不同结果，如果没有等于，我在输入框输入的数据，实体类数据不会刷新，加上等号，完成数据双向绑定。

密码输入框中输入123456

android:text="@={viewmodel.user.mPassWord}"

密码输入框中输入123456，而打印出来是12345，并没有完成双向绑定

android:text="@{viewmodel.user.mPassWord}"

<?xml version="1.0" encoding="utf-8"?>
<layout
    xmlns:android="http://schemas.android.com/apk/res/android">
    <data>
        <variable
        name="user"
        type="com.franzliszt.mvvmtest.model.User" />
        <variable
            name="viewmodel"
            type="com.franzliszt.mvvmtest.viewmodel.ViewModel" />
    </data>
    <LinearLayout
        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"
        >
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingTop="40dp">
        </LinearLayout>
        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:paddingLeft="30dp"
            android:text="账号密码登录"
            android:textColor="#000000"
            android:textSize="30sp"
            android:layout_marginTop="20dp"/>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:layout_margin="20dp">
            <EditText
                android:id="@+id/username"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:hint="用户名"
                android:paddingLeft="10dp"
                android:singleLine="true"
                android:textColor="#ff000000"
                android:textSize="15sp"
                android:text="@={viewmodel.user.mUserName}"
                />
        </LinearLayout>
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="20dp">
            <EditText
                android:id="@+id/password"
                android:layout_width="match_parent"
                android:layout_height="40dp"
                android:layout_marginTop="10dp"
                android:hint="密   码"
                android:paddingLeft="10dp"
                android:password="true"
                android:textColor="#ff000000"
                android:textSize="15sp"
                android:text="@={viewmodel.user.mPassWord}"
                />
        </LinearLayout>
        <Button
            android:id="@+id/login"
            android:layout_width="200dp"
            android:layout_height="wrap_content"
            android:layout_marginLeft="80dp"
            android:layout_marginTop="10dp"
            android:background="#1A73E8"
            android:text="登录"
            android:textColor="#ffffff"
            android:textSize="15sp"
            android:onClick="@{viewmodel.Login}"/>
    </LinearLayout>
</layout>

视图与数据绑定

初始化User类的数据，完成视图与数据绑定

public class MainActivity extends AppCompatActivity {
    private ActivityMainBinding binding;
    private User user;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate( savedInstanceState );
        binding = DataBindingUtil.setContentView( this,R.layout.activity_main );
        user = new User( "admin","12345" );
        binding.setViewmodel( new ViewModel( binding,user ) );
    }
}

Android——MVC、MVP、MVVM框架实现登录示例

MVC

描述

缺点

优点

MVP

效果图

描述

缺点

优点

代码解析

视图效果图

建立实体类

建立实体类接口

实现实体类接口

设置P层

建立交互接口

数据绑定

MVVM

效果图

描述

代码解析

导入dataBinding

实体类

建立viewmodel

xml绑定数据

视图与数据绑定

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