ganchuanpu 阅读(6) 评论(0)

前言

  开发一个app时,常用Activity和Fragment,由于操作方便Fragment越来越受欢迎,这样就避免不了Activity和Fragment、Fragment和Fragment之间的通信,我们知道Fragment和Fragment之间不能直接进行通信的,而是通过Activity进行通信。那么Activity和Fragment有几种通信方式呢,它们的优缺点又是什么?

一 常用的Activity和Fragment几种通信方式

1 通过Handle
在Activity创建一个Handle机制实例,然后在创建Fragment的通过构造方法把Handle实例传递过去,这样Fragment就可以往Activity传送数据了。但这样如下缺点:
(1)Activity和Fragment之间耦合性增大;
(2)Activity处理后的结果不能实时反馈给Fragment;
(3)提高了内存泄漏风险;
2 使用static变量
缺点很明确增大内存消耗;
3 使用广播
分别在Activity和Fragment中注册广播,这样就可以实现通信了。其缺点:
(1)性能差,有延迟,用户体验就会差;
(2)一般使用的是标准广播,一个发送,多个接收者,大材小用,性能差;
(3)代码冗余;
(4)传播的数据有限;
4 EventBus 、rxBus(俗称万能油)
其使用方法参考官方文档,其优点就是实用起来简单方便,其缺点也很明显:
(1)EventBus 、rxBus其内部使用的是反射机制,那么其性能就会降低;
(2)代码维护困难(不熟悉的项目代码的新人很难找到实现的方法在是如何调用的);
(3)数据返回困难,它们是单向传递;
5 普通接口
在Fragment写一个接口,让Activity去实现这个接口,通过这个接口把Activity与Fragment绑定在一起,这样Activity和Fragment实时进行通信了,其实谷歌推荐就是这么干的,由于每个Fragment都写一个接口,就会造成代码冗余;如果Fragment少的话还好,多的话,Activity实现多个接口,显得Activity头部很大,况且接口的命名也是一个问题;

二 万能接口

如果在5的基础能够解决代码冗余、接口命名就好了,我们知道一个函数包括函数名、函数体、参数、返回值,那么就可以通过搭建一个简单的框架实现上述问题。
1 建立基类
public abstract  class Function {
    /** 方法名 */
    public String mFunctionName ;

    public Function (String funName){
        this.mFunctionName = funName;
    }

}

2 建立无(有)参数无(有)四类

/**
 *  无参无返回值
 * <h3>Description</h3>
 * TODO
 * <h3>Author</h3> luzhenbang
 * <h3>Date</h3> 2018/1/4 16:13
 * <h3>Copyright</h3> Copyright (c)2018 Shenzhen TL  Co., Ltd. Inc. All rights reserved.
 */
public abstract class FunctionNoParamNoResult extends Function {

    public FunctionNoParamNoResult(String funName) {
        super(funName);
    }

    public abstract void function();

}

 

/**
 *  有参无返回值
 * <h3>Description</h3>
 * TODO
 * <h3>Author</h3> luzhenbang
 * <h3>Date</h3> 2018/1/4 16:13
 * <h3>Copyright</h3> Copyright (c)2018 Shenzhen TL  Co., Ltd. Inc. All rights reserved.
 */

public abstract class FunctionWithParamOnly<Param> extends Function {
    public FunctionWithParamOnly(String funName) {
        super(funName);
    }
    public abstract void function(Param param);
}    

 

/**
 *  有参有返回值
 * <h3>Description</h3>
 * TODO
 * <h3>Author</h3> luzhenbang
 * <h3>Date</h3> 2018/1/4 16:13
 * <h3>Copyright</h3> Copyright (c)2018 Shenzhen TL  Co., Ltd. Inc. All rights reserved.
 */

public abstract class FunctionWithParamWithResult<Result,Param> extends Function {
    public FunctionWithParamWithResult(String funName) {
        super(funName);
    }
    public abstract Result function(Param param);
}

 

/**
 *  无参有返回值
 * <h3>Description</h3>
 * TODO
 * <h3>Author</h3> luzhenbang
 * <h3>Date</h3> 2018/1/4 16:13
 * <h3>Copyright</h3> Copyright (c)2018 Shenzhen TL  Co., Ltd. Inc. All rights reserved.
 */

public abstract class FunctionWithResultOnly<Result> extends Function {
    public FunctionWithResultOnly(String funName) {
        super(funName);
    }
    public abstract Result function();
}

  

3 建立管理器类

public class FunctionManager {

private static FunctionManager instance = null;
    public static final String TAG = FunctionManager.class.getSimpleName() + "-------->";

    /**容器,用来存储方法名字 key 对应的方法名 value 对应的是 参数返回对象*/
    private HashMap<String,FunctionWithParamWithResult> mFunctionWithParamWithResultHashMap = null;
    private HashMap<String,FunctionWithParamOnly> mFunctionWithParamsOnlyHashMap = null;
    private HashMap<String,FunctionWithResultOnly> mFunctionWithResultOnlyHashMap = null;
    private HashMap<String,FunctionNoParamNoResult> mFunctionNoParamNoResultHashMap = null;


    private FunctionManager() {
mFunctionNoParamNoResultHashMap = new HashMap<>();
        mFunctionWithParamWithResultHashMap = new HashMap<>();
        mFunctionWithParamsOnlyHashMap = new HashMap<>();
        mFunctionWithResultOnlyHashMap = new HashMap<>();
    }


public static FunctionManager getInstance() {
if (null == instance){
instance = new FunctionManager();
        }
return instance;
    }


/**
     * 添加无参无返回值的方法
     * @return
     */
    public FunctionManager addFunction(FunctionNoParamNoResult function){
mFunctionNoParamNoResultHashMap.put(function.mFunctionName,function);
        return this;
    }


/**
     * 添加有返回值的方法
     * @return
     */
    public FunctionManager addFunction(FunctionWithResultOnly function){
mFunctionWithResultOnlyHashMap.put(function.mFunctionName,function);
        return this;
    }


/**
     * 添加有参数的方法
     * @return
     */
    public FunctionManager addFunction(FunctionWithParamOnly function){
mFunctionWithParamsOnlyHashMap.put(function.mFunctionName,function);
        return this;
    }



/**
     * 添加有参有返回值的方法
     * @return
     */
    public FunctionManager addFunction(FunctionWithParamWithResult function){
mFunctionWithParamWithResultHashMap.put(function.mFunctionName,function);
        return this;
    }


/**
     * 调用无返回值无参数的方法
     * @param funName
     */
    public void invokeNoAll (String funName) throws NullPointerException {
if (TextUtils.isEmpty(funName)){
            Log.e(TAG,"funName is null !");
        }else {
if ( null != mFunctionNoParamNoResultHashMap){
                FunctionNoParamNoResult function =  mFunctionNoParamNoResultHashMap.get(funName);
                if (null != function){
                    function.function();
                }else {
                    Log.e(TAG,"function is null !");
                }
            }else {
throw new NullPointerException("mFunctionNoParamNoResultHashMap can not be null ,please first init FunctionManager !");
            }
        }
    }


/**
     * 调用有参数的方法
     * @param funName
     */
   public <Param> void invokeWithParamOnly (String funName,Param param) throws NullPointerException {
if (TextUtils.isEmpty(funName)){
            Log.e(TAG,"funName is null !");
        }else {
if ( null != mFunctionWithParamsOnlyHashMap){
                FunctionWithParamOnly<Param> function =  mFunctionWithParamsOnlyHashMap.get(funName);
                if (null != function){
                    function.function(param);
                }else {
                    Log.e(TAG,"function is null !");
                }
            }else {
throw new NullPointerException("mFunctionWithParamsOnlyHashMap can not be null ,please first init FunctionManager !");
            }
        }
    }


/**
     * 调用有返回值的方法
     * @param funName
     */
   public <Result> Result invokeWithResultOnly (String funName, Class<Result> c) throws NullPointerException {
if (TextUtils.isEmpty(funName)){
            Log.e(TAG,"funName is null !");
        }else {
if ( null != mFunctionWithResultOnlyHashMap){
                FunctionWithResultOnly function =  mFunctionWithResultOnlyHashMap.get(funName);
                if (null != function){
if ( null != c){
return c.cast(function.function());
                    }else {
return (Result) function.function();
                    }
                }else {
                    Log.e(TAG,"function is null !");
                }
            }else {
throw new NullPointerException("mFunctionWithParamsOnlyHashMap can not be null ,please first init FunctionManager !");
            }
        }
return null;

   }

/**
     * 调用有参数有返回值的方法
     * @param funName
     */
    public <Result,Param> Result invokeWithAll (String funName, Class<Result> c,Param param) throws NullPointerException {
if (TextUtils.isEmpty(funName)){
            Log.e(TAG,"funName is null !");
        }else {
if ( null != mFunctionWithParamWithResultHashMap){
                FunctionWithParamWithResult<Result,Param> function =  mFunctionWithParamWithResultHashMap.get(funName);
                if (null != function){
if ( null != c){
return c.cast(function.function(param));
                    }else {
return function.function(param);
                    }
                }else {
                    Log.e(TAG,"function is null !");
                }
            }else {
throw new NullPointerException("mFunctionWithParamsOnlyHashMap can not be null ,please first init FunctionManager !");
            }
        }
return null;

    }
}

4 在Activity写一个方法

public void setFunctionForFragment(String tag){
if (TextUtils.isEmpty(tag)){
        Log.e(MainActivity.class.getSimpleName(),"tag is null !");
        return;
    }
    BaseFragment fragment = (BaseFragment) fm.findFragmentByTag(tag);
    FunctionManager functionManager = FunctionManager.getInstance();

    functionManager.addFunction(new FunctionNoParamNoResult(FunctionNoParamNoResult) {
@Override
        public void function() {
            Toast.makeText(MainActivity.this, "无参无返回值", Toast.LENGTH_SHORT).show();
        }
    });

    functionManager.addFunction(new FunctionWithResultOnly<String>(FunctionWithResultOnly) {
@Override
        public String function() {
return "无参有返回值";
        }
    });

    functionManager.addFunction(new FunctionWithParamOnly<String>(FunctionWithParamOnly) {
@Override
        public void function(String o) {
            Toast.makeText(MainActivity.this, o, Toast.LENGTH_SHORT).show();
        }
    });

    functionManager.addFunction(new FunctionWithParamWithResult<String,String>(FunctionWithParamWithResult) {
@Override
        public String function(String o) {
return o;
        }
    });

    fragment.setFunctionManager(functionManager);
}

5 编辑一个Fragment基类(实用Fragment的时候直接集成该类就可以了),并绑定上面建立的接口

public class BaseFragment extends Fragment{

public FunctionManager mFunctionManager;
    private MainActivity mainActivity;

    public void setFunctionManager(FunctionManager mFunctionManager) {
this.mFunctionManager = mFunctionManager;
    }

@Override
    public void onAttach(Context context) {
super.onAttach(context);
        if (context instanceof MainActivity) {
mainActivity  = (MainActivity) context;
            mainActivity.setFunctionForFragment(getTag());
        } else {
throw new RuntimeException(context.toString()
                    + " must implement OnFragmentInteractionListener");
        }
    }

@Override
    public void onDetach() {
super.onDetach();
        mainActivity = null;
    }

}

6 继承BaseFragment

public class NoParamNoResultFragment extends BaseFragment {

private Handler  mHandler;

    public NoParamNoResultFragment(Handler  handler) {
// Required empty public constructor
        this.mHandler  = handler;
    }


@Override
    public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        if (getArguments() != null) {
        }
    }

@Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
// Inflate the layout for this fragment
        View  view  = inflater.inflate(R.layout.fragment_no_param_no_result, container, false);

        view.findViewById(R.id.txt_handle).setOnClickListener(new View.OnClickListener() {
@Override
            public void onClick(View v) {
                Message  message = mHandler.obtainMessage();
                message.what = 0x123;
                message.obj = "handle 通信";
                mHandler.sendMessage(message);
            }
        });


        view.findViewById(R.id.txt_noALl).setOnClickListener(new View.OnClickListener() {
@Override
            public void onClick(View v) {
mFunctionManager.invokeNoAll(MainActivity.FunctionNoParamNoResult);

            }
        });
        view.findViewById(R.id.txt_result).setOnClickListener(new View.OnClickListener() {
@Override
            public void onClick(View v) {
//                mFunctionManager.invokeNoAll(MainActivity.FunctionNoParamNoResult);
                String result =  mFunctionManager.invokeWithResultOnly(MainActivity.FunctionWithResultOnly,String.class);
                Toast.makeText(getActivity(), result, Toast.LENGTH_SHORT).show();
            }
        });
        view.findViewById(R.id.txt_param).setOnClickListener(new View.OnClickListener() {
@Override
            public void onClick(View v) {
mFunctionManager.invokeWithParamOnly(MainActivity.FunctionWithParamOnly,"有参无返回值");
            }
        });
        view.findViewById(R.id.txt_withAll).setOnClickListener(new View.OnClickListener() {
@Override
            public void onClick(View v) {
                String result =  mFunctionManager.invokeWithAll(MainActivity.FunctionWithParamWithResult,String.class,"有参有返回值");
                Toast.makeText(getActivity(), result, Toast.LENGTH_SHORT).show();
            }
        });
        return view;
    }
}

说明,上述在点击控件的时候,会触发在Activity添加的方法,这样就可以实现Activity与Fragment实时通信,近而实现Fragment之间的通信  

https://gitee.com/lzbgit/AppInterface