如何创建一个接口，从一个片段信息到Android的活动？ [英] How to create an interface to get info from a Fragment to an Android Activity?

问题描述

在过去的日子里，我一直拼命地试图建立一个简单的片段的Andr​​oid应用程序（我用两次）。我想要的片段的EditText盒的内容传递到一个新的活动。我只是无法弄清楚如何从片段获得这些内容。我到目前为止是这样的：

Over the past days I've desperately been trying to build an android app with a simple fragment (which I use twice). I want to pass the contents of the fragments' EditText-boxes to a new activity. I just can't figure out how to get those contents from the fragments. What I have so far is this:

我有我的 edit_text_fragment.xml ：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >
    <EditText 
        android:id="@+id/my_edit_text"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:hint="my hint" />
</LinearLayout>

和相应的 MyEditTextFragment.java ：

public class MyEditTextFragment extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.edit_text_fragment, container, false);
        return view;
    }
}

我然后用这个片段我两次的main.xml 是这样的：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">
    <fragment 
        android:id="@+id/detailfragment_placeholder"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        class="com.example.fragmenttester5.MyEditTextFragment" />
    <fragment 
        android:id="@+id/detailfragment_placeholder2"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        class="com.example.fragmenttester5.MyEditTextFragment" />
    <Button 
        android:id="@+id/submit_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Submit all of it" />
</LinearLayout>

在我MainActivity我迷上了按钮，一个新的活动：

and in my MainActivity I hooked up the button to a new activity:

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Button submitButton = (Button) findViewById(R.id.submit_button);
        submitButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v){
                Intent intent = new Intent(MainActivity.this, OtherActivity.class);
                intent.putExtra("result1", "the_result_from_the_first_editText");
                intent.putExtra("result2", "the_result_from_the_second_editText");
                startActivity(intent);
            }
        });
    }
}

我的认为的我现在需要定义某种在片段接口，但我怎么也找不到。我读了几个例子和教程（如这个），但他们却没有意义，我在所有。我不明白的code给出，我只是不知道如何调整我的用例。

I think I now need to define some kind of interface in the Fragment, but I can't find how. I read a couple examples and tutorials (like this one), but they make no sense to me at all. I don't understand the code given and I just don't understand how to adjust it for my use case.

所以我的问题;任何人可以帮助我从活动中得到片段的内容是什么？例子将是非常非常值得欢迎的，因为我只是在敲我的头撞在墙上这里..

So my question; can anybody help me to get the contents of the fragment from within the activity? Examples would be very very welcome since I'm just banging my head against the wall here..

推荐答案

所以，你会创建一个接口与活动谈如果该事件发生的在的的片段。对于这种情况，你可以简单地在片段的方法访问的活动可以调用。因此，

So you'd create an Interface to talk with the Activity if the event happened in the Fragment. For situations like this, you can simply make an accessible method in the Fragment that the Activity can call. So

public class MyEditTextFragment extends Fragment {
    private EditText mEditText;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.edit_text_fragment, container, false);
        return view;
    }

    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);

        mEditText = (EditText) getView().findViewById(R.id.my_edit_text);
    }

    public Editable getText() {
        return mEditText.getText();
    }
}

然后

public class MainActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final MyEditTextFragment fragment1 = (MyEditTextFragment)
            getFragmentManager().findFragmentById(R.id.detailfragment_placeholder);

        final MyEditTextFragment fragment2 = (MyEditTextFragment)
            getFragmentManager().findFragmentById(R.id.detailfragment_placeholder2);

        Button submitButton = (Button) findViewById(R.id.submit_button);
        submitButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v){

                String firstResult = fragment1.getText().toString();
                String secondResult = fragment2.getText().toString();

                Intent intent = new Intent(MainActivity.this, OtherActivity.class);
                intent.putExtra("result1", firstResult);
                intent.putExtra("result2", secondResult);
                startActivity(intent);
            }
        });
    }
}

这假设您在 FragmentTransaction 分配片段标记。一定要检查空片段（不再赘述）

This assumes that you assigned the Fragment tags in your FragmentTransaction. Be sure to check for null Fragments (omitted for brevity)

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