MVC讲解

我们开发过程中，经常用到MVC，MVP，MVVM等架构。MVC是基础，所以我们先来学习下什么是MVC模式。

我们开发过程中，经常用到MVC，MVP，MVVM等架构。MVC是基础，所以我们先来学习下什么是MVC模式。

MVC分为三部分

M(model)V(view)C(controller)

Model:负责数据读取，业务逻辑，状态保存等。

View：数据展示，用户交互

Controller:View层和Model层通过controller来进行连接。

MVC使用了策略模式。我们可以在Controller当中更换我们的model和view，来达到显示不同的数据和展示不同的UI。

在android当中，activity常常充当了controller和view。

我们写一个例子，用activity充当controller，用fragment来做view。我们可以使用策略模式来更换model和view。

Model

package com.yuanxuzhen.testandroid.mvc.bean;

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


public class UserInfo implements Parcelable {
    public String name;
    public long id;
    public String sex;
    public int age;

    public UserInfo(String name, long id, String sex, int age) {
        this.name = name;
        this.id = id;
        this.sex = sex;
        this.age = age;
    }


    protected UserInfo(Parcel in) {
        name = in.readString();
        id = in.readLong();
        sex = in.readString();
        age = in.readInt();
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(name);
        dest.writeLong(id);
        dest.writeString(sex);
        dest.writeInt(age);
    }

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

    public static final Creator CREATOR = new Creator() {
        @Override
        public UserInfo createFromParcel(Parcel in) {
            return new UserInfo(in);
        }

        @Override
        public UserInfo[] newArray(int size) {
            return new UserInfo[size];
        }
    };

    @Override
    public String toString() {
        return "UserInfo{" +
                "name='" + name + ''' +
                ", id=" + id +
                ", sex='" + sex + ''' +
                ", age=" + age +
                '}';
    }
}

package com.yuanxuzhen.testandroid.mvc;

import com.yuanxuzhen.testandroid.mvc.bean.UserInfo;


public interface baseModel {
    UserInfo getUserInfo();
}

package com.yuanxuzhen.testandroid.mvc.model;

import com.yuanxuzhen.testandroid.mvc.baseModel;
import com.yuanxuzhen.testandroid.mvc.bean.UserInfo;


public class YuanpingModel implements baseModel {
    @Override
    public UserInfo getUserInfo() {
        UserInfo info = new UserInfo("Yuanping", 2, "female", 32);
        return info;
    }
}

package com.yuanxuzhen.testandroid.mvc.model;

import com.yuanxuzhen.testandroid.mvc.baseModel;
import com.yuanxuzhen.testandroid.mvc.bean.UserInfo;


public class YuanxuzhenModel implements baseModel {
    @Override
    public UserInfo getUserInfo() {
        UserInfo info = new UserInfo("Yuanxuzhen", 1, "male", 35);
        return info;
    }
}

view

package com.yuanxuzhen.testandroid.mvc.view;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

import com.yuanxuzhen.base.baseActivity;
import com.yuanxuzhen.base.ThreadUtils;
import com.yuanxuzhen.testandroid.databinding.ActivityUserInfoBinding;
import com.yuanxuzhen.testandroid.mvc.baseModel;
import com.yuanxuzhen.testandroid.mvc.model.YuanpingModel;
import com.yuanxuzhen.testandroid.mvc.model.YuanxuzhenModel;

public class UserInfoActivity extends baseActivity {

    ActivityUserInfoBinding binding;
    baseModel mModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityUserInfoBinding.inflate(getLayoutInflater());
        mModel = new YuanpingModel();
        setContentView(binding.getRoot());
        binding.getRoot().post(new Runnable() {
            @Override
            public void run() {
                Bundle bundle = new Bundle();
                bundle.putParcelable("user_info", mModel.getUserInfo());
                showFragment(UserFragment2.class,
                        UserFragment1.class.getName(),
                        false,
                        bundle

                );
            }
        });
    }
}

package com.yuanxuzhen.testandroid.mvc.view;

import android.os.Bundle;

import androidx.fragment.app.Fragment;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import com.yuanxuzhen.testandroid.R;
import com.yuanxuzhen.testandroid.databinding.FragmentUser1Binding;
import com.yuanxuzhen.testandroid.mvc.bean.UserInfo;


public class UserFragment1 extends Fragment {


    private static final String USER_INFO = "user_info";

    // TODO: Rename and change types of parameters
    private UserInfo userInfo;

    public UserFragment1() {
        // Required empty public constructor
    }


    public static UserFragment1 newInstance(UserInfo data) {
        UserFragment1 fragment = new UserFragment1();
        Bundle args = new Bundle();
        args.putParcelable(USER_INFO, data);
        fragment.setArguments(args);
        return fragment;
    }

    private UserInfo mUserInfo;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mUserInfo = getArguments().getParcelable(USER_INFO);
        }
    }

    FragmentUser1Binding binding;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        binding = FragmentUser1Binding.inflate(inflater);
        binding.tvUserinfo.setText(mUserInfo.toString());
        return binding.getRoot();
    }
}

package com.yuanxuzhen.testandroid.mvc.view;

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import androidx.fragment.app.Fragment;

import com.yuanxuzhen.testandroid.databinding.FragmentUser1Binding;
import com.yuanxuzhen.testandroid.databinding.FragmentUser2Binding;
import com.yuanxuzhen.testandroid.mvc.bean.UserInfo;


public class UserFragment2 extends Fragment {


    private static final String USER_INFO = "user_info";

    // TODO: Rename and change types of parameters
    private UserInfo userInfo;

    public UserFragment2() {
        // Required empty public constructor
    }


    public static UserFragment2 newInstance(UserInfo data) {
        UserFragment2 fragment = new UserFragment2();
        Bundle args = new Bundle();
        args.putParcelable(USER_INFO, data);
        fragment.setArguments(args);
        return fragment;
    }

    private UserInfo mUserInfo;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mUserInfo = getArguments().getParcelable(USER_INFO);
        }
    }

    FragmentUser2Binding binding;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        binding = FragmentUser2Binding.inflate(inflater);
        binding.tvUserinfo.setText(mUserInfo.toString());
        
        return binding.getRoot();
    }
}

Controller

package com.yuanxuzhen.testandroid.mvc.view;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;

import com.yuanxuzhen.base.baseActivity;
import com.yuanxuzhen.base.ThreadUtils;
import com.yuanxuzhen.testandroid.databinding.ActivityUserInfoBinding;
import com.yuanxuzhen.testandroid.mvc.baseModel;
import com.yuanxuzhen.testandroid.mvc.model.YuanpingModel;
import com.yuanxuzhen.testandroid.mvc.model.YuanxuzhenModel;

public class UserInfoActivity extends baseActivity {

    ActivityUserInfoBinding binding;
    baseModel mModel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityUserInfoBinding.inflate(getLayoutInflater());
        mModel = new YuanpingModel();
        setContentView(binding.getRoot());
        binding.getRoot().post(new Runnable() {
            @Override
            public void run() {
                Bundle bundle = new Bundle();
                bundle.putParcelable("user_info", mModel.getUserInfo());
                showFragment(UserFragment2.class,
                        UserFragment1.class.getName(),
                        false,
                        bundle

                );
            }
        });
    }
}

我们可以在Controller部分随意的更换model与view。达到view和model的分离。

gitee地址

https://gitee.com/creat151/yuanxuzhen_test_android.git