android - 将字符串从 fragment 主要 Activity 传递到 viewpager 中的 fragment Activity

Question

我想将一个字符串传递给 fragment Activity (主要)中的所有 fragment (子)，也许这张图片可以解释我到底想做什么

https://dl.dropboxusercontent.com/u/57465028/SC20140205-163325.png

所以，从上图看...我想通过按下按钮将字符串从 edittext 传递到 viewpager 中的所有 Activity ...我该怎么做？

我尝试遵循此代码 https://stackoverflow.com/a/12739968/2003393但它不能解决我的问题..

请帮助我...我被卡住了

提前致谢。

这是我的 fragment Activity (MainActivity) 的代码

公共(public)类 Swipe_Menu 扩展了 FragmentActivity {

//String KeyWord;


//private static final String KEYWORD = "keyword";

private ViewPager _mViewPager;
private ViewPagerAdapter _adapter;
/** Called when the activity is first created. */

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    setContentView(R.layout.swipe_menu_image);


    Button Back = (Button)findViewById(R.id.account);
    ImageButton Search = (ImageButton)findViewById(R.id.search);
    EditText Keyword = (EditText)findViewById(R.id.keyword);

    final String KeyWord = Keyword.getText().toString(); 


    /**
     * Back button click event
     * */
    Back.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View arg0) {

            finish();
        }
    });



    setUpView();
    setTab();
}

protected void sendValueToFragments(String value) {
    // it has to be the same name as in the fragment
    Intent intent = new Intent("my_package.action.UI_UPDATE");
    intent.putExtra("UI_KEY", KeyWord  );
    LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}

这是我的 fragment ( child Activity )

public class Store_Swipe extends Fragment {

public static final String ACTION_INTENT = "my_package.action.UI_UPDATE";

String KeyWord;
private TextView kata_keyword;

protected BroadcastReceiver receiver = new BroadcastReceiver() {

    @Override
    public void onReceive(Context context, Intent intent) {
        if(ACTION_INTENT.equals(intent.getAction())) {
            String value = intent.getStringExtra("UI_KEY");
            updateUIOnReceiverValue(value);
        }
    }
};

private void updateUIOnReceiverValue(String value) {
    // you probably want this:
    KeyWord = value;
}

public static Fragment newInstance(Context context) {
    Store_Swipe f = new Store_Swipe();
    return f;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    IntentFilter filter = new IntentFilter(ACTION_INTENT);
    LocalBroadcastManager.getInstance(getActivity()).registerReceiver(receiver, filter);
}

@Override
public void onDestroy() {
    LocalBroadcastManager.getInstance(getActivity()).unregisterReceiver(receiver);
    super.onDestroy();
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    /*Bundle bundle = this.getArguments();
    KeyWord = bundle.getString("keyword");*/
    View view = inflater.inflate(R.layout.store_swipe, container, false);
    init(view);

    return view;

}

void init(View view) {
    kata_keyword = (TextView) view.findViewById(R.id.keyword);
    //ImageView image = (ImageView) view.findViewById(R.id.image_error);
    kata_keyword.setText(KeyWord);
}

Answer 1

您无法直接访问驻留在 ViewPager 中的 fragment ，因此您无法直接引用它们。

在这些情况下，我所做的是从 Activity 向 Fragments 发送广播消息。为此，在 fragment 中注册一个 BroadcatReceiver(在 onCreate 或 onCreateView 中 - 您的决定)m，为该接收器设置自定义操作(例如 "my_package.actions.internal.BROADCAST_ACTION")，不要忘记从补充方法中注销接收器。

当你想从 Activity 中发送消息时，使用上述操作创建一个 Intent ，在 Intent 额外添加字符串并发送广播。

在你的接收者的 onReceive 方法中(在 fragment 中)，从 intent 参数中获取字符串，然后你就有了字符串。

有道理吗？

编辑:为了提供一些代码，下面是我要对 fragment 所做的更改:

public class Store_Swipe extends Fragment {

    public static final String ACTION_INTENT = "my_package.action.UI_UPDATE";

    protected BroadcastReceiver receiver = new BroadcastReceiver() {

        @Override
        public void onReceive(Context context, Intent intent) {
            if(ACTION_INTENT.equals(intent.getAction())) {
                String value = intent.getStringExtra("UI_KEY");
                updateUIOnReceiverValue(value);
            }
        }
    };

    private void updateUIOnReceiverValue(String value) {
        // you probably want this:
        kata_keyword.setText(value);
    }

    String KeyWord;
    private TextView kata_keyword;

    public static Fragment newInstance(Context context) {
        Store_Swipe f = new Store_Swipe();
        return f;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        IntentFilter filter = new IntentFilter(ACTION_INTENT);
        LocalBroadcastManager.getInstance(getActivity()).registerReceiver(receiver, filter);
    }

    @Override
    public void onDestroy() {
        LocalBroadcastManager.getInstance(getActivity()).unregisterReceiver(receiver);
        super.onDestroy();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        Bundle bundle = this.getArguments();
        KeyWord = bundle.getString("keyword");
        View view = inflater.inflate(R.layout.store_swipe, container, false);
        init(view);

        return view;

    }

    void init(View view) {
        kata_keyword = (TextView) view.findViewById(R.id.keyword);
        ImageView image = (ImageView) view.findViewById(R.id.image_error);
        kata_keyword.setText(KeyWord);
    }
}

我将从 Activity 中获得的代码，参数是来自 EditText 的值:

protected void sendValueToFragments(String value) {
    // it has to be the same name as in the fragment
    Intent intent = new Intent("my_package.action.UI_UPDATE");
    intent.putExtra("UI_KEY", value);
    LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
}

您可以从在 onCreate 中设置的点击监听器中调用它:

findViewById(R.id.button_id).setOnClickListener(new OnClickListener() {            
    @Override
    public void onClick(View v) {
        String valueThatYouWantToSend = null; /// just the value
        sendValueToFragments(valueThatYouWantToSend);       
    }
});