Dagger2 +ButterKnife 框架集成和运用

Dagger2 是一个注入框架 ：简单说就是 对象注入 以前要new 的东西，现在通过Dagger2 直接提供 实现了一定程度的解耦合

一 环境配置 

  dependencies {        classpath 'com.android.tools.build:gradle:2.3.3'        classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'        // NOTE: Do not place your application dependencies here; they belong        // in the individual module build.gradle files    }

全文如下不细说，注意Butterknife 的原始自动生成代码用的  不是Apt  所以会发生冲突 将他的改成这样就都可以用了

apply plugin: 'com.android.application'apply plugin: 'com.jakewharton.butterknife'apply plugin: 'com.neenbedankt.android-apt'android {    compileSdkVersion 26    buildToolsVersion "26.0.1"    defaultConfig {        applicationId "com.example.cuizehui.estore"        minSdkVersion 19        targetSdkVersion 26        versionCode 1        versionName "1.0"        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"    }    buildTypes {        release {            minifyEnabled false            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'        }    }    //dagger2和butterknife冲突    packagingOptions{        exclude 'META-INF/services/javax.annotation.processing.Processor'    }}dependencies {    apply plugin: 'com.neenbedankt.android-apt'    compile fileTree(dir: 'libs', include: ['*.jar'])    androidTestCompile('com.android.support.test.espresso:espresso-core:2.2.2', {        exclude group: 'com.android.support', module: 'support-annotations'    })   /* apt 'com.google.dagger:dagger-compiler:2.10-rc4'*/    //dagger2    apt 'com.google.dagger:dagger-compiler:2.0'    compile 'com.google.dagger:dagger:2.0'    compile 'com.android.support:appcompat-v7:26.+'    compile 'com.android.support.constraint:constraint-layout:1.0.2'    compile 'com.android.support:design:26.+'    compile 'com.android.support:support-v4:26.+'    //butterknife    compile 'com.jakewharton:butterknife:8.8.1'    /*annotationProcessor 'com.jakewharton:butterknife-compiler:8.8.1'*/    //只需要改这一句    apt 'com.jakewharton:butterknife-compiler:+'    // circleimagerview    compile 'de.hdodenhof:circleimageview:2.1.0'    testCompile 'junit:junit:4.12'    provided 'org.glassfish:javax.annotation:10.0-b28'}

二 根据框架结构分三层

 Application  -->Activity --> view/fragment  大多数情况下都是这三层

参考文章：

http://www.jianshu.com/p/f4180ad30317

1

Application:  (因为ApplictionComponent 是Activity 的依赖项所以 在生成其他Component 时 需要依赖项的对象)

APPComponet的创建:

public class MyApplication extends Application{       //全局单例 注入器 并给其他注入器提供依赖    private ApplicationComponent appComponent;        @Override        public void onCreate() {            super.onCreate();            initAppComponent();        }    public User getUser() {        return user;    }    public void setUser(User user) {        this.user = user;    }    public  void  initAppComponent(){        appComponent= DaggerApplicationComponent                .builder()                .applicationModule(new ApplicationModule(this))                .build();    }    public static MyApplication getInstance(Context context){        return (MyApplication)context.getApplicationContext();    }    public ApplicationComponent getAppComponent(){            return  appComponent;    }}

AppComponent 文件（是一个接口文件 加注释 因为这里使用了单例模式所以依赖项后面要加作用范围 也就是作用域@注解）：

package com.example.cuizehui.estore.interfaces;import android.app.Application;import com.example.cuizehui.estore.MainActivity;import com.example.cuizehui.estore.module.ApplicationModule;import javax.inject.Singleton;import dagger.Component;/** * Created by cuizehui on 17-9-13. * * 注入器 */@Singleton@Component (modules = ApplicationModule.class)public interface ApplicationComponent {    Application getApplication();}

AppModule:文件 只是简单的提供了一个APP对象

package com.example.cuizehui.estore.module;import android.app.Application;import javax.inject.Singleton;import dagger.Module;import dagger.Provides;@Modulepublic class ApplicationModule {    private Application application;    public ApplicationModule(Application application){        this.application=application;    }    @Provides    @Singleton    public Application provideApplication(){        return application;    }}

2

MainActivity:

MainActivityComponet(由于前面的单例依赖项后面要加作用范围 也就是作用域@PreActivity):

package com.example.cuizehui.estore.interfaces;import com.example.cuizehui.estore.MainActivity;import com.example.cuizehui.estore.PreActivity;import com.example.cuizehui.estore.module.MainActivityModule;import dagger.Component;/** * Created by cuizehui on 17-9-14. * */@PreActivity@Component (modules = MainActivityModule.class,dependencies = ApplicationComponent.class)public interface MainActivityComponent {    void inject(MainActivity mainActivity);}

PreActivity():

package com.example.cuizehui.estore;import javax.inject.Scope;@Scopepublic @interface PreActivity {}

MainActivityModule:(这里实现了对一个listview adapter对象的创建和提供)

package com.example.cuizehui.estore.module;import android.util.Log;import java.util.ArrayList;import dagger.Module;import dagger.Provides;@Modulepublic class MainActivityModule {    //mainActivity 引用的获取  ,方便fragment  获取    private   MainActivity mainActivity;    public MainActivityModule(MainActivity mainActivity) {        this.mainActivity=mainActivity;    }    @Provides    @PreActivity    MainActivity provideMainActivity() {        return mainActivity;    }    @PreActivity    @Provides    public ArrayList<BasePagerView> providePagerViews(){        ArrayList<BasePagerView>   pagerViews=new ArrayList<>();        pagerViews.add(new HomepagerView(mainActivity));        pagerViews.add(new ShopPagerView(mainActivity));        pagerViews.add(new OrderPagerView(mainActivity));        pagerViews.add(new MinePagerView(mainActivity));        return  pagerViews;    }    //通过参数的方法 也能进入到上面的代码 获取到对象 ，另外这段代码可以省略和直接在在MainViewPagerAdapter的构造函数中添加注解的效果一至    @PreActivity    @Provides    public MainViewPagerAdapter providemainViewPagerAdapter(ArrayList<BasePagerView> pagerViewslist){        MainViewPagerAdapter mainViewPagerAdapter=new MainViewPagerAdapter(pagerViewslist);        return  mainViewPagerAdapter;    }}

MainActivityComponet的注入（在MainAcitivity中完成）：

   MainActivityComponent  mainActivityComponent= DaggerMainActivityComponent                .builder()                .applicationComponent(appComponent)                .mainActivityModule(new MainActivityModule(this))                .build();        mainActivityComponent.inject(this);

这样的注入也可以在BaseActivity 中写好了接口方便 继承BaseActivity的Activity 进行注入，像这样：

    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_base);        setupActivityComponent(MyApplication.getInstance(this).getAppComponent());    }    protected abstract  void setupActivityComponent(ApplicationComponent appComponent);

3

view （普通类）注入

viewModule:

package com.example.cuizehui.estore.module;import android.content.Context;import android.util.Log;import java.util.ArrayList;import dagger.Module;import dagger.Provides;/** * Created by cuizehui on 17-9-19. */@Modulepublic class HomepagerViewModule {    public MainActivity mainActivity;    public HomepagerViewModule(MainActivity mainActivity) {        this.mainActivity=mainActivity;    }    @Provides    public ArrayList<ShopDaTa> provideShopDaTa(){        ArrayList<ShopDaTa> arrayList=new ArrayList<>();        //请求拉取数据放到 arraylist中        //模拟数据        ShopDaTa shopDaTa1=new ShopDaTa();        shopDaTa1.setProductName("dfsfd");        ShopDaTa shopDaTa2=new ShopDaTa();        shopDaTa1.setProductName("df43fd");        arrayList.add(shopDaTa1);        arrayList.add(shopDaTa2);        return  arrayList ;    }    @Provides    public HomeViewpagerLVAdapter provideLVadpter(ArrayList<ShopDaTa> arrayList){        Log.d("list.size:",arrayList.size()+"");        HomeViewpagerLVAdapter homeViewpagerLVAdapter=new HomeViewpagerLVAdapter(arrayList,mainActivity);        return  homeViewpagerLVAdapter;    }}

viewComponet:

package com.example.cuizehui.estore.interfaces;import dagger.Component;@Component(modules = HomepagerViewModule.class)public interface HomePagerViewComponent {    //注入方法    void inject(HomepagerView homepagerView);}

viewComponet 在view中注入：

        HomePagerViewComponent homePagerViewComponent= DaggerHomePagerViewComponent                .builder()                .homepagerViewModule(new HomepagerViewModule(mainActivity))                .build();        homePagerViewComponent.inject(this);

特别要注意注入一定要在使用之前，还需要注意所传的上下文之间的引用！！

参考文章：

Dagger2 入门：

http://www.jianshu.com/p/1d84ba23f4d2
http://www.jianshu.com/p/cd2c1c9f68d4

Dagger2 封装：

http://blog.csdn.net/u012702547/article/details/52200927

http://www.jcodecraeer.com/a/anzhuokaifa/androidkaifa/2015/0519/2892.html

三 ButterKnife在viewHolder下的bind

.........

 @Override    public View getView(int i, View view, ViewGroup viewGroup) {        ShopDaTa shopDaTa= shopDATAsarrayList.get(i);        LayoutInflater layoutInflater=LayoutInflater.from(context);        ViewHolder holder;        if (view != null) {            holder = (ViewHolder) view.getTag();        }        else {            view =layoutInflater.inflate(R.layout.shop_data_layout,null);            holder = new ViewHolder(view);         //   holder.textView =view.findViewById(R.id.productName_tV);            view.setTag(holder);        }        holder.textView.setText(shopDaTa.getProductName().toString());        return view;    }    //在holder中绑定    static class ViewHolder {         @BindView(R.id.productName_tV)         TextView textView;        public ViewHolder(View view) {           ButterKnife.bind(this, view);        }    }

参考文章：

http://www.jcodecraeer.com/a/anzhuokaifa/androidkaifa/2015/0519/2892.html