Android-MVP架構

MVP

簡介

MVP是模型(Model)、視圖(View)、主持人(Presenter)的縮寫,分別表明項目中3個不一樣的模塊。如圖所示:
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  • View 對應於Activity、Fragment,負責界面的繪製以及與用戶交互
  • Model 依然是業務邏輯和實體模型
  • Presenter 負責完成View於Model間的交互

    設計前思考:

  • 首先在咱們經常使用的MVC模式中,Activity承載了太多,作了不僅是視圖層的事情,而程序開發中最重要的 Context 通常也是在視圖層才擁有的,因此咱們須要把Context保持在視圖中。
  • MVP相對於MVC,MVP中是依賴Presenter這個接口任務調度器來實現任務調度,則視圖層中全部須要進行數據交互的,都須要將數據交給Presenter,而Presenter將調用Model來加載數據。
  • 在傳統的MVC中,我經常使用 initView()、initData()、initEvent()、doOther() 這幾個方法來實現數據流程加載、界面交互實現。如今咱們須要拆分出來,Activity從BaseActivity中實現。

通過這樣的構思,咱們能夠先實踐一下,咱們讓View來實現Model的接口,View來調用presenter,presenter利用面向接口編程的思想來調用接口實現對View的操做。實例以下:java

import android.content.Context;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import com.acheng.achengutils.mvp.model.BaseViewController;
import com.acheng.achengutils.mvp.presenter.BasePresenter;


/** * Created by pc859107393 on 2016/6/28. */
public abstract class BaseActivity<T extends BasePresenter, M extends BaseViewController> extends AppCompatActivity {

    public String TAG;  //當前Activity的標記

    protected T mPresenter;     //主持人角色

    protected abstract T initPresenter();    //獲取到主持人


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        TAG = String.format("%s::%s", getPackageName(), getLocalClassName());


        mPresenter = initPresenter();    //初始化Presenter,提供主持人,擁有主持人後才能提交界面數據給presenter

        setContentView(setLayoutId());

        initView();

        mPresenter.initData();

        initEvent();

        doOther();
    }

    protected void doOther() {

    }

    public Context getContext() {
        return this;
    }

    protected abstract void initEvent();


    protected abstract void initView();

    protected abstract int setLayoutId();

    @Override
    protected void onResume() {
        super.onResume();
        //若是presenter爲空的時候,咱們須要從新初始化presenter
        if (mPresenter == null) {
            mPresenter = initPresenter();
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
    }

    @Override
    public void onBackPressed() {   //返回按鈕點擊事件
        //當Activity中的 進度對話框正在旋轉的時候(數據正在加載,網絡延遲高,數據難以加載),關閉 進度對話框 , 而後能夠手動執行從新加載

        super.onBackPressed();
    }

    /** * 恢復界面後,咱們須要判斷咱們的presenter是否是存在,不存在則重置presenter * * @param savedInstanceState */
    @Override
    protected void onRestoreInstanceState(Bundle savedInstanceState) {
        super.onRestoreInstanceState(savedInstanceState);
        if (mPresenter == null)
            mPresenter = initPresenter();
    }

    /** * onDestroy中銷燬presenter */
    @Override
    protected void onDestroy() {
        super.onDestroy();
        mPresenter = null;
    }

}複製代碼

既然咱們的Activity已經設定好了BaseActivity,咱們須要接着完成BasePresenter,以下:android

import com.acheng.achengutils.mvp.model.BaseViewController;

/** * Created by acheng on 2016/7/14. */
public abstract class BasePresenter<D extends BaseViewController> {


    public D model;

    /** * 在子類的構造函數中,設定參數爲model,這時候能夠presenter調用接口來實現對界面的操做。 */
    public BasePresenter(D model) {
        this.model = model;
    }

    public abstract void initData();


}複製代碼

關於我這個Presenter的設計,我想說的是咱們須要將各層解耦,那麼個人presenter就不該該持有Android程序流轉的必然因子,如Context、Bundle、Intent、View等,若是咱們須要實現對界面的操做,必須經過調用咱們設定好的Model來實現,關於BaseModel更加簡單了,直接是一個空的接口文件,以下:git

public interface BaseViewController {
    //這裏面添加實現類須要實現的方法便可
}複製代碼

設計後的思考

  • presenter做爲主持人,應該隨着視圖的關閉而關閉,因此咱們須要在Activity和Fragment的關閉的時候,註銷相應的presenter
  • 在應用程序被銷燬的時候,咱們重啓了程序,可是這時應用的狀態若是不恢復到前面的狀態那麼咱們須要把對應的presenter重建
  • 在應用恢復後,若是想保持剛纔的狀態,那麼咱們須要在被銷燬前把視圖的狀態保存,而且恢復對應的狀態

說了這麼多,咱們直接手底下見真章:github

import android.Manifest;
import android.annotation.TargetApi;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.pm.PackageManager;
import android.net.Uri;
import android.os.Build;
import android.provider.Settings;
import android.support.v7.app.AlertDialog;
import android.view.View;
import android.widget.TextView;

import com.acheng.achengutils.mvp.view.BaseActivity;
import com.acheng.achengutils.utils.SPHelper;
import com.acheng.achengutils.widgets.AppUpdateDialog;
import com.acheng.achengutils.widgets.MustDoThingDailog;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import acheng1314.cn.a3dbuild.MyApplication;
import acheng1314.cn.a3dbuild.R;
import acheng1314.cn.a3dbuild.bean.LoginBean;
import acheng1314.cn.a3dbuild.view.activity.presenter.LoginActivityPresenter;
import acheng1314.cn.a3dbuild.view.activity.viewcontroller.LoginActivityViewController;
import acheng1314.cn.a3dbuild.widgets.MyProgressDialog;

/** * Created by pc859107393 on 2016/9/12 0012. */
public class LoginActivity extends BaseActivity<LoginActivityPresenter, LoginActivityViewController> implements LoginActivityViewController {

    private View mBt_login;
    private TextView mEt_username;  //用戶名
    private TextView mEt_password;  //密碼s


    final private int REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS = 124;
    private AppUpdateDialog appPermission;  //權限申請對話框
    private MyProgressDialog myProgressDialog;  //進度對話框

    @Override
    protected LoginActivityPresenter initPresenter() {
        return new LoginActivityPresenter(this);    //實例化LoginActivity的Presenter
    }

    @Override
    protected void initEvent() {
        mBt_login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                MyApplication.getInstance().outLog(TAG, "MDZZ");    //日誌輸出
                //調用Presenter的登陸的網絡請求,將用戶名和密碼傳遞過去
                mPresenter.doLogin(mEt_username.getText().toString(), mEt_password.getText().toString()); 



            }
        });
    }

    @Override
    protected void initView() {
        MyApplication.getInstance().addActivity(this);  //將Activity加入堆棧管理
        mEt_username = (TextView) findViewById(R.id.mEt_username);
        mEt_password = (TextView) findViewById(R.id.mEt_password);
        mBt_login = findViewById(R.id.mBt_login);
    }

    @Override
    protected void doOther() {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            List<String> permissionsNeeded = new ArrayList<String>();

            final List<String> permissionsList = new ArrayList<String>();
            if (!addPermission(permissionsList, Manifest.permission.WRITE_EXTERNAL_STORAGE))
                permissionsNeeded.add("手機存儲空間");
            if (!addPermission(permissionsList, Manifest.permission.READ_PHONE_STATE))
                permissionsNeeded.add("獲取手機狀態");
            if (!addPermission(permissionsList, Manifest.permission.CAMERA))
                permissionsNeeded.add("手機相機");
            if (!addPermission(permissionsList, Manifest.permission.ACCESS_COARSE_LOCATION))
                permissionsNeeded.add("手機位置");
// if (!addPermission(permissionsList, Manifest.permission.WRITE_SETTINGS))
// permissionsNeeded.add("手機設置");

            if (permissionsList.size() > 0) {
                if (permissionsNeeded.size() > 0) { //待申請的權限列表
                    // Need Rationale
                    String message = "你必須容許本APP使用:" + permissionsNeeded.get(0);
                    for (int i = 1; i < permissionsNeeded.size(); i++)
                        message = message + ", " + permissionsNeeded.get(i);
                    showMessageOKCancel(message,
                            new DialogInterface.OnClickListener() {
                                @TargetApi(Build.VERSION_CODES.M)
                                @Override
                                public void onClick(DialogInterface dialog, int which) {
                                    requestPermissions(permissionsList.toArray(new String[permissionsList.size()]),
                                            REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS);
                                }
                            });
                    return;
                }
                requestPermissions(permissionsList.toArray(new String[permissionsList.size()]),
                        REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS);
            }
        }
        super.doOther();
    }

    private void showMessageOKCancel(String message, DialogInterface.OnClickListener okListener) {
        new AlertDialog.Builder(this)
                .setMessage(message)
                .setPositiveButton("容許", okListener)
                .setNegativeButton("拒絕", null)
                .create()
                .show();
    }

    private boolean addPermission(List<String> permissionsList, String permission) {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
            if (checkSelfPermission(permission) != PackageManager.PERMISSION_GRANTED) {
                permissionsList.add(permission);
                if (!shouldShowRequestPermissionRationale(permission))
                    return false;
            }
        }
        return true;
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        switch (requestCode) {
            case REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS: {
                Map<String, Integer> perms = new HashMap<String, Integer>();
                // Initial
                perms.put(Manifest.permission.WRITE_EXTERNAL_STORAGE, PackageManager.PERMISSION_GRANTED);
                perms.put(Manifest.permission.READ_PHONE_STATE, PackageManager.PERMISSION_GRANTED);
                perms.put(Manifest.permission.CAMERA, PackageManager.PERMISSION_GRANTED);
                perms.put(Manifest.permission.ACCESS_COARSE_LOCATION, PackageManager.PERMISSION_GRANTED);
                // Fill with results
                for (int i = 0; i < permissions.length; i++)
                    perms.put(permissions[i], grantResults[i]);
                // Check for ACCESS_FINE_LOCATION
                if (perms.get(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED
                        && perms.get(Manifest.permission.READ_PHONE_STATE) == PackageManager.PERMISSION_GRANTED
                        && perms.get(Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED
                        && perms.get(Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
                    //通過用戶受權,得到全部權限
                    if (appPermission != null) {
                        appPermission = null;
                    }
                    // All Permissions Granted
                } else {    //未獲得用戶受權
                    // Permission Denied
                    appPermission = new AppUpdateDialog(AppUpdateDialog.IMPORTANT, "一些權限未被容許,請在設置中受權!", getContext(), new AppUpdateDialog.NeedDoThing() {
                        @Override
                        public void mustDoThing() {
                            Uri packageURI = Uri.parse("package:" + getPackageName());
                            Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS, packageURI);
                            startActivity(intent);
                        }
                    });
                }
            }
            break;
            default:
                super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }

    @Override
    protected void onResume() {
        super.onResume();
        doOther();
    }

    @Override
    protected int setLayoutId() {
        return R.layout.activity_login;
    }

    @Override
    public void showDailog(String msg) {
        new MustDoThingDailog("提示", msg, getContext(), new MustDoThingDailog.NeedDoThing() {
            @Override
            public void mustDoThings() {

            }
        });
    }

    @Override
    public void showProgressD() {
        if (null == myProgressDialog)
            myProgressDialog = new MyProgressDialog("登錄", "正在登陸···", getContext());
        else
            myProgressDialog.show();
    }

    @Override
    public void disProgressD() {
        if (null != myProgressDialog)
            myProgressDialog.dismiss();
    }

    @Override
    public void openHome(LoginBean bean) {

        SPHelper.setString(getContext(), getContext().getString(R.string.user), getContext().getString(R.string.username), mEt_username.getText().toString());
        SPHelper.setString(getContext(), getContext().getString(R.string.user), getContext().getString(R.string.password), mEt_password.getText().toString());
        SPHelper.setString(getContext(), getContext().getString(R.string.user), getContext().getString(R.string.userId), bean.getResult().getUserId());
        SPHelper.setString(getContext(), getContext().getString(R.string.user), getContext().getString(R.string.token), bean.getResult().getToken());

        startActivity(new Intent(getContext(), HomeActivity.class));

        finish();
    }
}複製代碼

其實上面咱們當中能夠看到咱們前臺界面拿到用戶數據後,調用presenter的doLogin方法,把用戶名和密碼傳遞過去,而後咱們在Presenter中請求網絡而後再經過調用接口實現數據回傳。以下:編程

import com.acheng.achengutils.gsonutil.GsonUtils;
import com.acheng.achengutils.mvp.presenter.BasePresenter;
import com.acheng.achengutils.utils.CipherUtils;
import com.acheng.achengutils.utils.StringUtils;
import com.kymjs.rxvolley.RxVolley;
import com.kymjs.rxvolley.client.HttpCallback;
import com.kymjs.rxvolley.client.HttpParams;
import com.kymjs.rxvolley.http.VolleyError;

import acheng1314.cn.a3dbuild.MyApplication;
import acheng1314.cn.a3dbuild.bean.LoginBean;
import acheng1314.cn.a3dbuild.hostApi.MyApi;
import acheng1314.cn.a3dbuild.view.activity.viewcontroller.LoginActivityViewController;

/** * Created by pc859107393 on 2016/9/12 0012. */
public class LoginActivityPresenter extends BasePresenter<LoginActivityViewController> {
    /** * 在子類的構造函數中,設定參數爲model,這時候能夠presenter調用接口來實現對界面的操做。 * * @param model */
    public LoginActivityPresenter(LoginActivityViewController model) {
        super(model);
    }

    @Override
    public void initData() {

    }

    public void doLogin(String name, String pwd) {
        //用戶名和密碼不能爲空
        if (StringUtils.isEmpty(name) || StringUtils.isEmpty(pwd)) {
            model.showDailog("用戶名或密碼不能爲空!"); //調用model的錯誤提示對話框
            return;
        }

        //密碼MD5加密
        pwd = CipherUtils.small32md5(pwd);
        HttpParams params = new HttpParams();
        params.put("userName", name);
        params.put("passWord", pwd);
        RxVolley.post(MyApi.LoginApi, params, new HttpCallback() {
            @Override
            public void onSuccess(String t) {
                super.onSuccess(t);
                //數據不爲空再進行數據處理
                try {
                    if (null != t) {
                        MyApplication.getInstance().outLog("輸出", t);
                        LoginBean bean = new GsonUtils().toBean(t, LoginBean.class);
                        if (null != bean) {
                            if (bean.getCode() == 0) {
                                //請求成功
                                model.openHome(bean);
                            } else if (bean.getCode() == 1) {
                                model.showDailog("登陸失敗,賬戶不存在");
                            } else if (bean.getCode() == 2) {
                                model.showDailog("登陸失敗,密碼錯誤");
                            } else {
                                model.showDailog("登陸失敗,其餘未知錯誤");
                            }
                        }
                    }
                } catch (Exception e) {
                    e.printStackTrace();
                    model.showDailog("登陸失敗,其餘未知錯誤");
                }


            }

            @Override
            public void onFailure(VolleyError error) {
                super.onFailure(error);
                model.showDailog("登陸失敗,其餘未知錯誤");
            }

            @Override
            public void onFinish() {
                super.onFinish();
                model.disProgressD();   //model的關閉對話框的接口
            }

            @Override
            public void onPreStart() {
                super.onPreStart();
                model.showProgressD();  //model的進度對話框
            }
        });


    }
}複製代碼

咱們上面能夠看到咱們如今只要把請求網絡的數據傳遞上去就能夠完成單元測試了,這樣子咱們就達到了咱們數據流轉的單元測試的標準。api

既然咱們都看到了Presenter對model的調用,那麼咱們直接貼上model再對比Activity就能明白了咱們是怎麼完成這個設計的。網絡

public interface LoginActivityViewController extends BaseViewController {
    /** * 顯示信息提示對話框 * @param msg message */
    void showDailog(String msg);

    /** * 顯示進度對話框 */
    void showProgressD();

    /** * 關閉對話框 */
    void disProgressD();

    /** * 登錄成功跳轉到其餘界面 * @param bean */
    void openHome(LoginBean bean);
}複製代碼

咱們看到這裏,不少哥們可能又會不明白,爲何咱們能控制界面呢?以下:架構

//咱們在程序中,presenter直接調用的model,可是model是被View實現了的。
public class LoginActivity extends BaseActivity<LoginActivityPresenter, LoginActivityViewController> implements LoginActivityViewController {
    @Override
    public void showDailog(String msg) {
        //實現了model的顯示對話框的方法
        new MustDoThingDailog("提示", msg, getContext(), new MustDoThingDailog.NeedDoThing() {
            @Override
            public void mustDoThings() {

            }
        });
    }

    @Override
    public void showProgressD() {
        //這是顯示進度對話框的,實現了model的方法
    }

    @Override
    public void disProgressD() {
        //這是實現了moel的關閉進度對話框的方法
    }

    @Override
    public void openHome(LoginBean bean) {

        //實現了model的打開其餘頁面的方法
    }
}複製代碼

因此咱們的MVP執行的步驟其實就是:用戶執行操做 -> 調用presenter(完成獨立的數據處理) -> 調用model的方法控制界面 -> 展現給用戶app


而後應該又有哥們會問我,爲何你的基類中會有<>這種括號括起來的東西,恩恩這個是泛型,主要是用來講明他們是哪一類的東西,經過泛型來解耦就能夠在基類中整合更多的東西。具體的要我來講明的話,我只能說「就不!!!」,我須要任性一回。關於MVP更好的介紹能夠看下github的項目TheMvp,這個是個人偶像@張濤寫的喲。

總結

  • 在mvp架構中,咱們須要在基類中拿到每一個界面對應的presenter和model,則咱們須要讓程序知道每一個對應的presenter和model.
  • 爲了減小沒必要要的代碼開銷,咱們須要把每一個activity和Fragment的公共方法抽取出來,寫入基類中.
  • 在基類中,咱們須要將具體的presenter和model解耦,則須要泛型進行類型轉換來解除耦合.
  • 泛型解除耦合後,咱們須要在每一個具體的view中來持有presenter和實現model層的接口.而且經過每一個view關聯的presenter調用model的某個方法來控制view.
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