博客

工具类：

public class InjectUtils {

    //(1)
    public static void injectView(Activity activity){
        Class<? extends Activity> cls = activity.getClass();
        //获得此类的所有成员
        Field[] declaredFields = cls.getDeclaredFields();
        for (Field field : declaredFields) {
            //判断属性是否被注解声明
           if (field.isAnnotationPresent(InjectView.class)){
               InjectView injectView = field.getAnnotation(InjectView.class);
               //获得了注解中设置的id
               int id = injectView.value();
               View view = activity.findViewById(id);
               //反射设置属性的值
               field.setAccessible(true);//设置访问权限，允许操作private的属性
               try {
                   field.set(activity,view);
               } catch (IllegalAccessException e) {
                   e.printStackTrace();
               }
           }

        }
    }





      //(2)
     public static void injectAutowired(Activity activity) {
        Class<? extends Activity> cls = activity.getClass();
        //获得数据
        Intent intent = activity.getIntent();
        Bundle extras = intent.getExtras();
        if (extras == null) {
            return;
        }

        //获得此类所有的成员
        Field[] declaredFields = cls.getDeclaredFields();
        for (Field field : declaredFields) {
            if (field.isAnnotationPresent(Autowired.class)) {
                Autowired autowired = field.getAnnotation(Autowired.class);
                //获得key
                String key = TextUtils.isEmpty(autowired.value()) ? field.getName() : autowired.value();

                if (extras.containsKey(key)) {
                    Object obj = extras.get(key);
                    // todo Parcelable数组类型不能直接设置，其他的都可以.
                    //获得数组单个元素类型
                    Class<?> componentType = field.getType().getComponentType();
                    //当前属性是数组并且是 Parcelable（子类）数组
                    if (field.getType().isArray() &&
                            Parcelable.class.isAssignableFrom(componentType)) {
                        Object[] objs = (Object[]) obj;
                        //创建对应类型的数组并由objs拷贝

                        Object[] objects = Arrays.copyOf(objs, objs.length, (Class<? extends Object[]>) field.getType());
                        obj = objects;
                    }

                    field.setAccessible(true);
                    try {
                        field.set(activity, obj);
                    } catch (IllegalAccessException e) {
                        e.printStackTrace();
                    }
                }
            }
}

工具类中的（1）

InjectView注解

@Retention(RetentionPolicy.RUNTIME)
public @interface InjectView {
    @IdRes int value();
}

使用：在Activity中使用先绑定

 InjectUtils.injectView(this);



    @InjectView(R.id.rv)
    private RecyclerView rv;

工具类中的（2）

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME)
public @interface Autowired {
    String value() default "";
}

使用：

ArrayList<UserParcelable> userParcelableList = new ArrayList<>();

        userParcelableList.add(new UserParcelable("g"));
        Intent intent = new Intent(this, SecondActivity.class)
                .putExtra("name", "xixi")
                .putExtra("attr","h")
                .putExtra("array", new int[]{1, 2, 3, 4, 5, 6})
                .putExtra("userParcelable", new UserParcelable("f"))
                .putExtra("userParcelables", new UserParcelable[]{new UserParcelable("a")})
                .putExtra("users",new UserSerializable[]{new UserSerializable("b")})
                .putExtra("strs",new String[]{"1","2"})
                .putParcelableArrayListExtra("userParcelableList", userParcelableList);
        startActivity(intent);






public class UserParcelable implements Parcelable {
    String name;

    public UserParcelable(String name) {
        this.name = name;
    }

    protected UserParcelable(Parcel in) {
        name = in.readString();
    }

    @Override
    public void writeToParcel(Parcel dest, int flags) {
        dest.writeString(name);
    }

    @Override
    public int describeContents() {
        return 0;
    }

    public static final Creator<UserParcelable> CREATOR = new Creator<UserParcelable>() {
        @Override
        public UserParcelable createFromParcel(Parcel in) {
            return new UserParcelable(in);
        }

        @Override
        public UserParcelable[] newArray(int size) {
            return new UserParcelable[size];
        }
    };

    @Override
    public String toString() {
        return "UserParcelable{" +
                "name='" + name + '\'' +
                '}';
    }
}





public class UserSerializable implements java.io.Serializable {
    String name;

    public UserSerializable(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "UserSerializable{" +
                "name='" + name + '\'' +
                '}';
    }
}

public class SecondActivity extends AppCompatActivity {

    int i,j;
    String k;

    @Autowired
    String name;

    @Autowired("attr")
    String attr;

    @Autowired
    int[] array;

    @Autowired
    UserParcelable userParcelable;

    @Autowired
    UserParcelable[] userParcelables;

    @Autowired
    List<UserParcelable> userParcelableList;

    @Autowired("users")
    UserSerializable[] userSerializables;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        InjectUtils.injectAutowired(this);
        System.out.println(toString());
    }

    @Override
    public String toString() {
        return "SecondActivity{" +
                "name='" + name + '\'' +
                ", attr='" + attr + '\'' +
                ", array=" + Arrays.toString(array) +
                ", userParcelable=" + userParcelable +
                ", userParcelables=" + Arrays.toString(userParcelables) +
                ", userParcelableList=" + userParcelableList +
                ", userSerializables=" + Arrays.toString(userSerializables) +
                '}';
    }
}