@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface CheckNet {String value() default "亲，您的网络链接有问题哦!";
}

 1 public class ViewHelper {
 2
 3     private Activity mActivity;
 4     private View mView;
 5
 6     public ViewHelper(Activity activity) {
 7         this.mActivity = activity;
 8     }
 9
10     public ViewHelper(View v) {
11         this.mView = v;
12     }
13
14     public View findViewById(@IdRes int id) {
15
16         return mActivity == null ? mView.findViewById(id) : mActivity.findViewById(id);
17     }
18 }

  1 public class ViewUtils {
  2
  3     public static void inject(Activity activity) {
  4         inject(new ViewHelper(activity), activity);
  5     }
  6
  7     //为了兼容View
  8     public static void inject(View v) {
  9         inject(new ViewHelper(v), v);
 10     }
 11
 12     //为了兼容Fragment
 13     public static void inject(View v, Object o) {
 14         inject(new ViewHelper(v), o);
 15     }
 16
 17
 18     /**
 19      * 最终都调用这个方法
 20      *
 21      * @param helper View的帮助类  通过这个类根据id找到相应View
 22      * @param o      相关对象  Activity  view 等  从那个类传进来的
 23      */
 24     private static void inject(ViewHelper helper, Object o) {
 25         injectField(helper, o);
 26         injectMethod(helper, o);
 27     }
 28
 29     /**
 30      * 通过@ViewById得到id注入相应的View
 31      *
 32      * @param helper View帮助类
 33      * @param o      相关对象  Activity  view 等  从那个类传进来的
 34      */
 35     private static void injectField(ViewHelper helper, Object o) {
 36         //1.获取到Object中所有的带有@ViewById的字段
 37         Class<?> clazz = o.getClass();
 38         //获取所有的字段
 39         Field[] fields = clazz.getDeclaredFields();
 40         for (Field field : fields) {
 41             //2.获取到相应的value值，也就是id值得到相应的View
 42             ViewById viewById = field.getAnnotation(ViewById.class);
 43             if (viewById != null) {
 44                 int viewId = viewById.value();
 45                 View view = helper.findViewById(viewId);
 46                 if (view != null) {
 47                     try {
 48                         //3.设置字段值，也就是给字段赋值
 49                         field.setAccessible(true);//为了使不被修饰符梭影响
 50                         field.set(o, view);
 51                     } catch (Exception e) {
 52                         e.printStackTrace();
 53                     }
 54                 }
 55             }
 56         }
 57     }
 58
 59     /**
 60      * 设置点击事件
 61      *
 62      * @param helper View帮助类
 63      * @param o      相关对象  Activity  view 等  从那个类传进来的
 64      */
 65     private static void injectMethod(ViewHelper helper, Object o) {
 66         //1.获取到所有带有@OnClick的方法
 67         Class<?> clazz = o.getClass();
 68         Method[] methods = clazz.getDeclaredMethods();//获取所有方法
 69         for (Method method : methods) {
 70             OnClick onClick = method.getAnnotation(OnClick.class);
 71             if (onClick != null) {
 72                 //网络检测
 73                 CheckNet checkNet = method.getAnnotation(CheckNet.class);
 74                 String hint = null;
 75                 if (checkNet != null) {
 76                     hint = checkNet.value();
 77                 }
 78
 79                 //2.获取到相应的value值,也就是要设置点击时间的id数组
 80                 int[] values = onClick.value();
 81                 for (int viewId : values) {
 82                     //3.通过id获取到相应的Vie,然后设置点击事件
 83                     View view = helper.findViewById(viewId);
 84                     if (view != null) {
 85                         view.setOnClickListener(new DeclaredOnClickListener(method, o, hint));
 86                     }
 87                 }
 88             }
 89         }
 90     }
 91
 92     private static class DeclaredOnClickListener implements View.OnClickListener {
 93
 94         //设置点击事件的方法
 95         private Method mMethod;
 96         //在那个类中
 97         private Object mObject;
 98         //是否检查网络
 99         private String mNoNetHint;
100
101         public DeclaredOnClickListener(Method method, Object o, String hint) {
102             this.mMethod = method;
103             this.mObject = o;
104             this.mNoNetHint = hint;
105         }
106
107         @Override
108         public void onClick(View v) {
109             try {
110                 mMethod.setAccessible(true);//所有修饰符都可以搞事
111                 if (mNoNetHint != null && !isNetConnected(v.getContext())) {
112                     Toast.makeText(v.getContext(), mNoNetHint, Toast.LENGTH_SHORT).show();
113                     return;
114                 }
115                 mMethod.invoke(mObject, v);//可以避免点击闪退
116             } catch (Exception e) {
117                 e.printStackTrace();
118                 try {
119                     mMethod.invoke(mObject, (Object[]) null);//当方法体里面没有参数时候调用改方法，执行没有方法体的修饰的函数
120                 } catch (Exception e1) {
121                     e1.printStackTrace();
122                 }
123             }
124         }
125     }
126
127
128     /**
129      * 检测网络是否连接
130      *
131      * @return
132      */
133     private static boolean isNetConnected(Context context) {
134         ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
135         if (cm != null) {
136             NetworkInfo[] infos = cm.getAllNetworkInfo();
137             if (infos != null) {
138                 for (NetworkInfo ni : infos) {
139                     if (ni.isConnected()) {
140                         return true;
141                     }
142                 }
143             }
144         }
145         return false;
146     }
147
148 }

public class MainActivity extends AppCompatActivity {@ViewById(R.id.icon)private ImageView mIconIv;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);ViewUtils.inject(this);mIconIv.setImageResource(R.drawable.icon);}@OnClick(R.id.icon)@CheckNet          // 检测网络private void onClick(View view) {Toast.makeText(this, "图片点击了", Toast.LENGTH_LONG).show();}
}