【轉載】android中MVP模式

轉載地址：http://blog.csdn.net/knxw0001/article/details/39637273#comments
1. 明確需求，界面如下：可存，可根據id讀取數據。

包結構圖

2. 建立bean

public class UserBean {  
     private String mFirstName;  
     private String mLastName;  

     public UserBean(String firstName, String lastName) {  
            this. mFirstName = firstName;  
            this. mLastName = lastName;  
     }  

     public String getFirstName() {  
            return mFirstName;  
     }  

     public String getLastName() {  
            return mLastName;  
     }  
}

1. 建立model（處理業務邏輯，這裏指數據讀寫），先寫接口，後寫實現

    public interface IUserModel {  
         void setID(int id);  

         void setFirstName(String firstName);  

         void setLastName(String lastName);  

         int getID();  

         UserBean load(int id);// 通過id讀取user信息,返回一個UserBean  
    }  

實現不在這裏寫了。

1. 建立view（更新ui中的view狀態），這裏列出需要操作當前view的方法，也是接口

public interface IUserView {  
     int getID();  

     String getFristName();  

     String getLastName();  

     void setFirstName(String firstName);  

     void setLastName(String lastName);  
} 

1. 建立presenter（主導器，通過iView和iModel接口操作model和view），activity可以把所有邏輯給presenter處理，這樣java邏輯就從手機的activity中分離出來。

public class UserPresenter {  
     private IUserView mUserView;  
     private IUserModel mUserModel;  

     public UserPresenter(IUserView view) {  
            mUserView = view;  
            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()); // 通過調用IUserView的方法來更新顯示  
            mUserView.setLastName(user.getLastName());  
     }  
} 

1. activity中實現iview接口，在其中操作view，實例化一個presenter變量。

public class MainActivity extends Activity implements OnClickListener,IUserView {  

     UserPresenter presenter;  
     EditText id,first,last;  
     @Override  
     protected void onCreate(Bundle savedInstanceState) {  
            super.onCreate(savedInstanceState);  
           setContentView(R.layout. activity_main);  

           findViewById(R.id. save).setOnClickListener( this);  
           findViewById(R.id. load).setOnClickListener( this);  
            id = (EditText) findViewById(R.id. id);  
            first = (EditText) findViewById(R.id. first);  
            last = (EditText) findViewById(R.id. last);  

            presenter = new UserPresenter( this);  
     }  

     @Override  
     public void onClick(View v) {  
            switch (v.getId()) {  
            case R.id. save:  
                 presenter.saveUser(getID(), getFristName(), getLastName());  
                 break;  
            case R.id. load:  
                 presenter.loadUser(getID());  
                 break;  
            default:  
                 break;  
           }  
     }  

     @Override  
     public int getID() {  
            return new Integer( id.getText().toString());  
     }  

     @Override  
     public String getFristName() {  
            return first.getText().toString();  
     }  

     @Override  
     public String getLastName() {  
            return last.getText().toString();  
     }  

     @Override  
     public void setFirstName(String firstName) {  
            first.setText(firstName);  
     }  

     @Override  
     public void setLastName(String lastName) {  
            last.setText(lastName);  
     }  

} 

1. 所謂的mvp，即是（model-處理業務邏輯（主要是數據讀寫，或者與後臺通信（其實也是讀寫數據）），view-處理ui控件，presenter-主導器，操作model和view）

2. 需求，這個是《android開發必知的50個訣竅》一書中的mvp章節的需求。
   在splash頁面中，判斷是否有網絡連接，有則跳到下個頁面，無則彈出一條消息通知用戶，同時在檢查網絡是否正常的期間顯示一個進度條。

3. 類目錄結構
   

    3. model接口和實現  
    public interface INetConnect {  
         boolean isNetConnect( Context context);  
    }  
    public class NetConnect implements INetConnect {  

         @Override  
         public boolean isNetConnect(Context context) {  
                if (context != null) {  
                    ConnectivityManager mConnectivityManager = (ConnectivityManager) context  
                              .getSystemService(Context. CONNECTIVITY_SERVICE);  
                    NetworkInfo mNetworkInfo = mConnectivityManager  
                               .getActiveNetworkInfo();  
                     if (mNetworkInfo != null) {  
                          return mNetworkInfo.isAvailable();  
                    }  
               }  
                return false;  
         }  

    }  

    4. view接口  
    public interface ISplashView {  
         void showProcessBar();  
         void hideProcessBar();  
         void showNetError();  
         void startNextActivity();  
    }  

    5. presenter實現  
    public class SplashPresenter {  
         private INetConnect connect;  
         private ISplashView iView;  

         public SplashPresenter(ISplashView iView){  
                this. iView = iView;  
                connect = new NetConnect();  
         }  

         public void didFinishLoading(Context context){  
                iView.showProcessBar();  
                if( connect.isNetConnect(context)){  
                     iView.startNextActivity();  
               } else{  
                     iView.showNetError();  
               }  
                iView.hideProcessBar();  
         }  
    }  

    6.activity中代碼  
    public class MainActivity extends Activity implements ISplashView{  

         SplashPresenter presenter;  
         private ProgressDialog progressBar;  
         @Override  
         protected void onCreate(Bundle savedInstanceState) {  
                super.onCreate(savedInstanceState);  
               setContentView(R.layout. activity_main);  

                presenter = new SplashPresenter( this);  
         }  

         @Override  
         protected void onResume() {  
                super.onResume();  
                presenter.didFinishLoading( this);  
         }  

         @Override  
         public void showProcessBar() {  
                if ( progressBar == null) {  
                     progressBar = new ProgressDialog( this);  
                     progressBar.setCancelable( true);  
                     progressBar.setCanceledOnTouchOutside( true);  
                     progressBar.setMessage( "更新數據中，請稍後" );  
               }  
                progressBar.show();  
         }  

         @Override  
         public void hideProcessBar() {  
                progressBar.hide();  
         }  

         @Override  
         public void showNetError() {  
               Toast. makeText(this, "暫無網絡", Toast.LENGTH_SHORT).show();  
         }  

         @Override  
         public void startNextActivity() {  
               Toast. makeText(this, "跳到下個activity", Toast.LENGTH_SHORT).show();  
         }  

    }