android使用篇(四) 注解依赖注入IOC实现绑定控件

android使用篇(三) MVC模式中提到一个问题:

1) 视图层(View):一般採用XML文件进行界面的描写叙述,使用的时候能够很方便的引入,可是用xml编写了,又须要在Acitvity声明而且实例化,有点麻烦,考虑是否能做一个类似注解实现匹配,或者写一个类获取xml的各个节点然后自己主动进行封装,当然,这仅仅是个想法,以后再实现。

今天最终把这个想法实现了,使用依赖注入IOC注解实现对activity中控件的实例化。

先普及一下java的反射机制和注解机制的知识:

下面引用大神的两篇文章:

JAVA反射机制  


java 注解 

完毕后仅仅须要: @ViewInject(id=R.id.btn1,click="btnClick") TextView btn1;  就可以完毕实例化,并加入�点击事件

基本思路: 

一,public abstract class D3Activity extends Activity    写一个类继承Activity。

二,重写  setContentView   在此方法实现注解。

三,Field[] fields = activity.getClass().getDeclaredFields();    获取activity中的字段属性

四, field.getAnnotation(ViewInject.class);         获取字段的注解属性

五, field.set(activity,sourceView.findViewById(viewId));       实例化控件

大功告成,到此已实现了注解实现对android中activity和xml文件的实例化问题。

另外也能够实现注解对控件的事件加入�,具体


分三个类实现:

实现注解类:

注解类可注入 id---相应xml的id,各种点击事件,可自定义

@Target(ElementType.FIELD)
@Retention(RetentionPolicy.RUNTIME) 
public @interface D3View {
 public int id() default 0;
 public String click() default "";
 public String longClick() default "";
 public String itemClick() default "";
 public String itemLongClick() default "";
}


重写activity类,使用反射和注解实现实例化并添�事件:

public abstract class D3Activity extends Activity {

 public void setContentView(int layoutResID) {   super.setContentView(layoutResID);   initInjectedView(this);  }

 public void setContentView(View view, LayoutParams params) {   super.setContentView(view, params);   initInjectedView(this);  }

 public void setContentView(View view) {   super.setContentView(view);   initInjectedView(this);  }  

 private void initInjectedView(Activity activity){   initInjectedView(activity, activity.getWindow().getDecorView());  }      private void initInjectedView(Object activity,View sourceView){   Field[] fields = activity.getClass().getDeclaredFields();   //获取字段   if(fields!=null && fields.length>0){    for(Field field : fields){     try {      field.setAccessible(true);   //设为可訪问            if(field.get(activity)!= null )       continue;           D3View d3View = field.getAnnotation(D3View.class);      if(d3View!=null){              int viewId = d3View.id();       if(viewId == 0)        viewId = getResources().getIdentifier(field.getName(), "id",getPackageName());       if(viewId == 0)        Log.e("D3Activity", "field "+ field.getName() + "not found");              //关键,注解初始化,相当于 backBtn = (TextView) findViewById(R.id.back_btn);          field.set(activity,sourceView.findViewById(viewId));           //事件          setListener(activity,field,d3View.click(),Method.Click);       setListener(activity,field,d3View.longClick(),Method.LongClick);       setListener(activity,field,d3View.itemClick(),Method.ItemClick);       setListener(activity,field,d3View.itemLongClick(),Method.itemLongClick);      }     } catch (Exception e) {      e.printStackTrace();     }    }   }  }    private void setListener(Object activity,Field field,String methodName,Method method)throws Exception{   if(methodName == null || methodName.trim().length() == 0)    return;      Object obj = field.get(activity);      switch (method) {    case Click:     if(obj instanceof View){      ((View)obj).setOnClickListener(new EventListener(activity).click(methodName));     }     break;    case ItemClick:     if(obj instanceof AbsListView){      ((AbsListView)obj).setOnItemClickListener(new EventListener(activity).itemClick(methodName));     }     break;    case LongClick:     if(obj instanceof View){      ((View)obj).setOnLongClickListener(new EventListener(activity).longClick(methodName));     }     break;    case itemLongClick:     if(obj instanceof AbsListView){      ((AbsListView)obj).setOnItemLongClickListener(new EventListener(activity).itemLongClick(methodName));     }     break;    default:     break;   }  }    public enum Method{   Click,LongClick,ItemClick,itemLongClick  }   }


事件类: 实现了 OnClickListener, OnLongClickListener, OnItemClickListener,OnItemLongClickListener ,能够自己扩展

public class EventListener implements OnClickListener, OnLongClickListener, OnItemClickListener,OnItemLongClickListener {

	private Object handler;
	
	private String clickMethod;
	private String longClickMethod;
	private String itemClickMethod;
	private String itemLongClickMehtod;
	
	public EventListener(Object handler) {
		this.handler = handler;
	}
	
	public EventListener click(String method){
		this.clickMethod = method;
		return this;
	}
	
	public EventListener longClick(String method){
		this.longClickMethod = method;
		return this;
	}
	
	public EventListener itemLongClick(String method){
		this.itemLongClickMehtod = method;
		return this;
	}
	
	public EventListener itemClick(String method){
		this.itemClickMethod = method;
		return this;
	}
	
	public boolean onLongClick(View v) {
		return invokeLongClickMethod(handler,longClickMethod,v);
	}
	
	public boolean onItemLongClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) {
		return invokeItemLongClickMethod(handler,itemLongClickMehtod,arg0,arg1,arg2,arg3);
	}
	
	public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {
		
		invokeItemClickMethod(handler,itemClickMethod,arg0,arg1,arg2,arg3);
	}
	
	public void onClick(View v) {
		
		invokeClickMethod(handler, clickMethod, v);
	}
	
	
	private static Object invokeClickMethod(Object handler, String methodName,  Object... params){
		if(handler == null) return null;
		Method method = null;
		try{   
			method = handler.getClass().getDeclaredMethod(methodName,View.class);
			if(method!=null)
				return method.invoke(handler, params);	
			else
				throw new RuntimeException("no such method:"+methodName);
		}catch(Exception e){
			e.printStackTrace();
		}
		
		return null;
		
	}
	
	
	private static boolean invokeLongClickMethod(Object handler, String methodName,  Object... params){
		if(handler == null) return false;
		Method method = null;
		try{   
			//public boolean onLongClick(View v)
			method = handler.getClass().getDeclaredMethod(methodName,View.class);
			if(method!=null){
				Object obj = method.invoke(handler, params);
				return obj==null?false:Boolean.valueOf(obj.toString());	
			}
			else
				throw new RuntimeException("no such method:"+methodName);
		}catch(Exception e){
			e.printStackTrace();
		}
		
		return false;
		
	}
	
	
	
	private static Object invokeItemClickMethod(Object handler, String methodName,  Object... params){
		if(handler == null) return null;
		Method method = null;
		try{   
			///onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3)
			method = handler.getClass().getDeclaredMethod(methodName,AdapterView.class,View.class,int.class,long.class);
			if(method!=null)
				return method.invoke(handler, params);	
			else
				throw new RuntimeException("no such method:"+methodName);
		}catch(Exception e){
			e.printStackTrace();
		}
		
		return null;
	}
	
	
	private static boolean invokeItemLongClickMethod(Object handler, String methodName,  Object... params){
		if(handler == null) throw new RuntimeException("invokeItemLongClickMethod: handler is null :");
		Method method = null;
		try{   
			///onItemLongClick(AdapterView<?> arg0, View arg1, int arg2,long arg3)
			method = handler.getClass().getDeclaredMethod(methodName,AdapterView.class,View.class,int.class,long.class);
			if(method!=null){
				Object obj = method.invoke(handler, params);
				return Boolean.valueOf(obj==null?false:Boolean.valueOf(obj.toString()));	
			}
			else
				throw new RuntimeException("no such method:"+methodName);
		}catch(Exception e){
			e.printStackTrace();
		}
		
		return false;
	}
}


到此已经完毕了,仅仅须要这样就可以实例化:

public class MainActivity extends D3Activity {
    
	//@ViewInject EditText input;   //id和属性名同样,自己主动匹配
	@ViewInject(id = R.id.input) EditText editText;     
	@ViewInject(click="btnClick") TextView btn1,btn2,btn3;
	
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
    }  

	public void btnClick(View v){
    	
    	switch (v.getId()) {
		case R.id.btn1:
			btn1.setText(editText.getText().toString());
			Toast.makeText(getApplicationContext(), "111", Toast.LENGTH_SHORT).show();
			break;
		
		case R.id.btn2:
			Toast.makeText(getApplicationContext(), "222", Toast.LENGTH_SHORT).show();

			break;
			
		case R.id.btn3:
			Toast.makeText(getApplicationContext(), "333", Toast.LENGTH_SHORT).show();
			break;

		default:
			break;
		}
    	
    }
    
}

相应xml布局文件:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    
    <EditText 
        android:id="@+id/input"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        
        />
    <TextView
        android:id="@+id/btn1"
        android:layout_marginTop="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="设置自己"
         />
	<TextView 
        android:id="@+id/btn2"
        android:layout_marginTop="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="btn2"
	    />
	
	
	<TextView 
        android:id="@+id/btn3"
        android:layout_marginTop="10dp"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="btn3"
	    />
</LinearLayout>


源代码已经放在了github,有兴趣的能够去看看 :https://github.com/mozhenhau/injectAndroid.git


posted @ 2014-09-02 19:19  hrhguanli  阅读(523)  评论(0编辑  收藏  举报