package com.example.ele_me.util;

 import java.lang.annotation.Retention;

 import java.lang.annotation.Target;

 import java.lang.annotation.ElementType; 

 import java.lang.annotation.RetentionPolicy;  

 /**

  * Use this annotation to mark the fields of your Activity as being injectable.

  * <p>

  * See the {@link Injector} class for more details of how this operates.

  */ 

 @Target({ ElementType.FIELD }) 

 @Retention(RetentionPolicy.RUNTIME) 

 public @interface InjectView { 

     /**

      * 這個java檔最精彩的地方是@interface，一般我們皆看到public Class去定義類型，而在injectview.java這裡卻使用了這樣public @interface的方法。

      */ 

     public int value(); 

 //所有對象都會被寫進value這個函數之中。

 }  java.lang.annotation.Retention;

 public enum RetentionPolicy {

 SOURCE,

 CLASS,

 RUNTIME

 }

 public enum ElementType {

 TYPE, FIELD, METHOD, PARAMETER, CONSTRUCTOR,

 LOCAL_VARIABLE, ANNOTATION_TYPE,PACKAGE

 }