IOC注解框架

写在前面

打造自己的简单IOC注解框架

1.创建annotation类

View

//代表Annotation的位置， FIELD属性 TYPE类上   CONSTRUCTOR构造函数上
@Target(ElementType.FIELD)
//代表什么时候生效  CLASS编译时 RUNTIME运行时  SOURCE源码时
@Retention(RetentionPolicy.RUNTIME)
public @interface ViewById {
   	int value();
}

点击监听

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface OnClick {
   	int[] value();
}

网络状态判断

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface CheckNet {
}

2.创建View的findViewById的辅助类

public class ViewFinder {
   	private Activity mActivity;
   	private View mView;

   	public ViewFinder(Activity activity) {
       	this.mActivity = activity;
   	}

   	public ViewFinder(View view) {
       	this.mView = view;
   	}

   	public View findViewById(int viewId) {
       	return mActivity != null ? mActivity.findViewById(viewId) : mView.findViewById(viewId);
   	}
}

3.创建工具类

public class ViewUtils {
   	public static void inject(Activity activity) {
		inject(new ViewFinder(activity), activity);
   	}

   	public static void inject(View view) {
		inject(new ViewFinder(view), view);
   	}

   	public static void inject(View view, Object object) {
		inject(new ViewFinder(view), object);
   	}
   	//兼容 上面三个方法，object ->  反射需要执行的类
   	private static void inject(ViewFinder finder, Object object) {
       	injectField(finder, object);
       	injectEvent(finder, object);
   	}

   
     // 注入属性    
   	private static void injectField(ViewFinder finder, Object object) {
       	//1.获取类里面的所有属性
       	Class<?> clazz = object.getClass();
       	// 获取所有属性包括私有和共有
       	Field[] fields = clazz.getDeclaredFields();
       	//2.获取ViewById找到view
       	for (Field field : fields) {
       	    ViewById viewById = field.getAnnotation(ViewById.class);
       	    if (viewById != null) {
       	        //获取注解里的id值->R.id.xx
       	        int viewId = viewById.value();
       	        //3.findViewById找到view
       	        View view = finder.findViewById(viewId);
       	        if (view != null) {
       	            //能够注入所有修饰符private public
       	            field.setAccessible(true);
       	            try {
       	                //4.动态注入扎到view
       	                field.set(object, view);
       	            } catch (IllegalAccessException e) {
       	                e.printStackTrace();
       	            }
       	        }
       	    }
       	}
   	}

   	private static void injectEvent(ViewFinder finder, Object object) {
       	Class<?> clazz = object.getClass();
       	Method[] methods = clazz.getDeclaredMethods();

       	for (Method method : methods) {
       	    OnClick onClick = method.getAnnotation(OnClick.class);
       	    if (onClick != null) {
       	        int[] viewIds = onClick.value();
       	        for (int viewId : viewIds) {
       	            View view = finder.findViewById(viewId);
       	            boolean isCheckNet = method.getAnnotation(CheckNet.class) != null;

       	            if (view != null) {
       	                view.setOnClickListener(new DeclaredOnClickListener(method, object, isCheckNet));
       	            }
       	        }
       	    }
       	}
   	}

   	private static class DeclaredOnClickListener implements View.OnClickListener {
       	private final Object mObject;
       	private final Method mMethod;
       	private final boolean mIsCheckNet;

       	public DeclaredOnClickListener(Method method, Object object, boolean isCheckNet) {
       	    this.mMethod = method;
       	    this.mObject = object;
       	    this.mIsCheckNet = isCheckNet;
       	}

       	@Override
       	public void onClick(View v) {
       	    if (mIsCheckNet) {
       	        if (!networkAvailable(v.getContext())) {
       	            Toast.makeText(v.getContext(), "网络不可用", Toast.LENGTH_SHORT).show();
       	            return;
       	        }
       	    }
       	    try {
       	        mMethod.setAccessible(true);
       	        mMethod.invoke(mObject, v);
       	    } catch (Exception e) {
       	        e.printStackTrace();
       	        try {
       	            mMethod.setAccessible(true);
       	            mMethod.invoke(mObject, null);
       	        } catch (Exception e1) {
       	            e1.printStackTrace();
       	        }
       	    }
       	}
   	}

   	private static boolean networkAvailable(Context context) {
       	try {
           	ConnectivityManager connectivityManager = (ConnectivityManager)
                   	context.getSystemService(Context.CONNECTIVITY_SERVICE);
           	NetworkInfo activeNetWorkInfo = connectivityManager.getActiveNetworkInfo();
           	if (activeNetWorkInfo != null && activeNetWorkInfo.isConnected()) {
               	return true;
           	}
       	} catch (Exception e) {
           	e.printStackTrace();
       	}
       	return false;
   	}
}

使用方法

@ViewById(R.id.test_tv)
   private TextView textView;


@CheckNet
   @OnClick(R.id.test_tv)
   private void onClick(View view) {
       Toast.makeText(this, "click", Toast.LENGTH_SHORT).show();
   }