MVP模式

• MVP的全稱是Model、View、Presenter，顧名思義，它將整個應用分爲三層
• View層：視圖層，包含和界面相關的功能，例如各類Activity、Fragment、View、Adapter等，該層專一於用戶的交互，實現設計師給出的界面、動畫等交互效果。View層通常會持有Presenter層的引用，或者也能夠經過依賴注入的方式得到Presenter實例，並將非UI的邏輯操做委託給Presenter
• Presenter層：邏輯控制層，充當中間人的角色，用來隔離VIew和Model，該層是經過從View層剝離控制邏輯部分而造成的，主要負責View層和Model層的控制和交互。例如接收VIew層的網絡數據加載請求，並分發給對應的Model處理，同時監聽Model層的處理結果，最終反饋給View層，從而實現界面的刷新
• Model層：封裝各類數據來源，例如遠程網絡數據，本地數據庫數據等，對Presenter層提供簡單易用的接口
• 代碼以下：
• UserInfoActivity（View層）

  public class UserInfoActivity extends Activity implements IUserInfoShow, View.OnClickListener {
  
      private final String TAG = UserInfoActivity.class.getCanonicalName();
      private UserInfoPresenter mUserInfoPresenter;
  
      @Override
      public void beforeLoading() {
          Log.e(TAG,"開始加載以前");
      }
  
      @Override
      public void afterLoading() {
          Log.i(TAG,"加載數據以後");
      }
  
  
      @Override
      public void getUserInfoSucc(UserInfo userInfo) {
          Log.i(TAG,"獲取UserInfo 成功"+userInfo.toString());
      }
  
      @Override
      public void getUserInfoFail(String msg) {
          Log.e(TAG,"獲取UserInfo Fail"+msg);
      }
  
  
      @Override
      protected void onCreate(@Nullable Bundle savedInstanceState) {
          super.onCreate(savedInstanceState);
          setContentView(R.layout.activity_userinfo);
          initEvent();
          initData();
      }
  
      private void initEvent() {
          findViewById(R.id.btn).setOnClickListener(this);
      }
  
      private void initData() {
          mUserInfoPresenter = new UserInfoPresenter(new GetUserInfoImpl(),this);
      }
  
      @Override
      public void onClick(View v) {
          if (mUserInfoPresenter != null){
              mUserInfoPresenter.getUserInfo(888);
          }
  
  
  
  
      }
  }
  

• Presenter層：

  • 業務邏輯：

    public interface IUserInfo {
         void getUserInfo(int id,OnUserInfoListener userInfoListener);
    }
    

     

  • 業務邏輯實現類

    public class GetUserInfoImpl implements IUserInfo {
    
        @Override
        public void getUserInfo(final int id, final OnUserInfoListener userInfoListener) {
            new Thread(){
                @Override
                public void run() {
                    super.run();
                    try {
                        Thread.sleep(2*1000);
                        if (id == 888){
                            UserInfo userInfo = new UserInfo();
                            userInfo.setAccount("JIM");
                            userInfo.setId(id);
                            userInfo.setPwd("lee");
                            userInfoListener.onGetSucc(userInfo);
                        }else{
                            String msg = "查無此人";
                            userInfoListener.onGetFail(msg);
                        }
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
    
                }
            }.start();
        }
    }
    

  • public interface OnUserInfoListener {
        void onGetSucc(UserInfo userInfo);
        void onGetFail(String msg);
    }
    

  • UserInfoPresenter：

    public class UserInfoPresenter {
        private IUserInfo getuserinfo;
        private IUserInfoShow userInfoShow;
    
        public UserInfoPresenter(IUserInfo getuserinfo, IUserInfoShow userInfoShow) {
            this.getuserinfo = getuserinfo;
            this.userInfoShow = userInfoShow;
        }
    
        public void getUserInfo(int id){
            userInfoShow.beforeLoading();
            if (getuserinfo!=null){
                getuserinfo.getUserInfo(id, new OnUserInfoListener() {
                    @Override
                    public void onGetSucc(UserInfo userInfo) {
                        userInfoShow.getUserInfoSucc(userInfo);
                        userInfoShow.afterLoading();
                    }
    
                    @Override
                    public void onGetFail(String msg) {
                        userInfoShow.getUserInfoFail(msg);
                        userInfoShow.afterLoading();
                    }
                });
            }
        }
    }
    

  • 和VIew交互的接口

    public interface IUserInfoShow {
        void beforeLoading();
        void afterLoading();
        void getUserInfoSucc(UserInfo userInfo);
        void getUserInfoFail(String msg);
    }

 

• • Model層：

    ublic class UserInfo {
        private int Id;
        private String Account;
        private String pwd;
    
        public int getId() {
            return Id;
        }
    
        public void setId(int id) {
            Id = id;
        }
    
        public String getAccount() {
            return Account;
        }
    
        public void setAccount(String account) {
            Account = account;
        }
    
        public String getPwd() {
            return pwd;
        }
    
        public void setPwd(String pwd) {
            this.pwd = pwd;
        }
    
        @Override
        public String toString() {
            return "UserInfo{" +
                    "Id=" + Id +
                    ", Account='" + Account + '\'' +
                    ", pwd='" + pwd + '\'' +
                    '}';
        }
    }