android的MVP模式以及接口的理解

来源：互联网发布：分岔分析软件编辑：程序博客网时间：2024/05/22 17:05

最近看了一下android开发的MVP模式以及接口，深有体会。
这里写图片描述
如图是MVP的一种简单结构，源码来自网上的例子
（http://blog.csdn.net/knxw0001/article/details/39637273）
1.

package com.mvp.bean;//用户数据public class UserBean {    private String mFirstName;    private String mLastName;    public UserBean(String firstName, String lastName) {        // TODO Auto-generated constructor stub        this.mFirstName = firstName;        this.mLastName = lastName;    }    public String getFirstName() {        return mFirstName;    }    public String getLastName() {        return mLastName;    }}

package com.mvp.model;import com.mvp.bean.UserBean;public interface IUserModel {    void setID(int id);    void setFirstName(String firstName);    void setLastName(String lastName);    UserBean load(int id);//接口中的方法没有具体实现，只是声明}

package com.mvp.model;import android.util.SparseArray;import com.mvp.bean.UserBean;//用户modol继承了接口public class UserModel implements IUserModel {    private String mFristName;    private String mLastName;    private int mID;    private SparseArray<UserBean> mUsererArray = new SparseArray<UserBean>();//下面都是重写的接口中的方法    @Override    public void setID(int id) {        // TODO Auto-generated method stub        mID = id;    }    @Override    public void setFirstName(String firstName) {        // TODO Auto-generated method stub        mFristName = firstName;    }    @Override    public void setLastName(String lastName) {        // TODO Auto-generated method stub        mLastName = lastName;        UserBean UserBean = new UserBean(mFristName, mLastName);        mUsererArray.append(mID, UserBean);    }    @Override//接口方法的具体实现    public UserBean load(int id) {        // TODO Auto-generated method stub        mID = id;        UserBean userBean = mUsererArray.get(mID, new UserBean("not found",                "not found"));        return userBean;    }}

package com.mvp.presenter;import com.mvp.bean.UserBean;import com.mvp.model.IUserModel;import com.mvp.model.UserModel;import com.mvp.view.IUserView;public class UserPresenter {    private IUserView mUserView;//这两个都是接口，通过实例化接口对象实现了“引用”，调用继承了该接口的类的方法    private IUserModel mUserModel;    public UserPresenter(IUserView view) {        mUserView = view;//muserview是一个接口，不需要新建对象        mUserModel = new UserModel();    }    public void saveUser(int id, String firstName, String lastName) {        mUserModel.setID(id);        mUserModel.setFirstName(firstName);        mUserModel.setLastName(lastName);    }    public void loadUser(int id) {        UserBean user = mUserModel.load(id);        mUserView.setFirstName(user.getFirstName());        mUserView.setLastName(user.getLastName());    }}

package com.mvp.view;public interface IUserView {    int getID();    String getFristName();    String getLastName();    void setFirstName(String firstName);    void setLastName(String lastName);}

package com.mvp.view;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import com.mvp.R;import com.mvp.presenter.UserPresenter;public class UserActivity extends Activity implements OnClickListener,        IUserView {    private EditText mFirstNameEditText, mLastNameEditText, mIdEditText;    private Button mSaveButton, mLoadButton;    private UserPresenter mUserPresenter;    @Override    protected void onCreate(Bundle savedInstanceState) {        // TODO Auto-generated method stub        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        findWidgets();        mUserPresenter = new UserPresenter(this);        mSaveButton.setOnClickListener(this);        mLoadButton.setOnClickListener(this);    }    @Override    public void onClick(View v) {        // TODO Auto-generated method stub        switch (v.getId()) {        case R.id.saveButton:            mUserPresenter.saveUser(getID(), getFristName(),                    getLastName());            break;        case R.id.loadButton:            mUserPresenter.loadUser(getID());            break;        default:            break;        }    }    @Override    public void setFirstName(String firstName) {        // TODO Auto-generated method stub        mFirstNameEditText.setText(firstName);    }    @Override    public void setLastName(String lastName) {        // TODO Auto-generated method stub        mLastNameEditText.setText(lastName);    }    @Override    public int getID() {        // TODO Auto-generated method stub        return Integer.parseInt(mIdEditText.getText().toString());    }    @Override    public String getFristName() {        // TODO Auto-generated method stub        return mFirstNameEditText.getText().toString();    }    @Override    public String getLastName() {        // TODO Auto-generated method stub        return mLastNameEditText.getText().toString();    }    void findWidgets() {        mFirstNameEditText = (EditText) findViewById(R.id.first_name_edt);        mLastNameEditText = (EditText) findViewById(R.id.last_name_edt);        mIdEditText = (EditText) findViewById(R.id.id_edt);        mSaveButton = (Button) findViewById(R.id.saveButton);        mLoadButton = (Button) findViewById(R.id.loadButton);    }}

代码中的注释已经说明了一切。
需要注意的：实例化的接口对象是为了能调用继承了该接口的类的方法；
继承接口的类必须实现接口中的所有方法，接口中的方法并不会写具体内容，只是相当于一个“声明”。
注意到了这些，整体架构的逻辑就十分好理解了，希望对java语法理解不深的android初学者可以好好体会一下

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