Question

我的RecyclerView包含非常复杂的项目，多个按钮/图像/文本。要访问每个按钮/图像，我在Adapter类中设置了单击Listeners。

但是现在我正在尝试添加功能来设置联系人铃声，我遇到了问题。

我正在调用onActivityResult方法：

Intent contactIntent = new Intent(Intent.ACTION_PICK);
                contactIntent.setType(ContactsContract.Contacts.CONTENT_TYPE);
                contactIntent.putExtra("RINGTONE_POSITION", position);
                ((Activity) context).startActivityForResult(contactIntent, CONTACT_CHOOSER_ACTIVITY_CODE );

并且工作正常。但问题出在这里：

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        switch (requestCode) {
....
...
...
}
}

我收到此错误：Cannot resolve method 'onActivityResult(int, int, android.content.Intent)' 有什么方法可以避免这种情况吗？或者是否可以在适配器类中使用此方法？如果不是我该怎么办？

Answer 1

你不能在任何Adapter类中使用它，这只是Activity内的一个方法，extends Activity每个类都能覆盖这个方法，但肯定不是适配器。

请参阅java中的Overrides

对于onActivityResult，请参阅Activity#onActivityResult(int, int, Intent)

对于类似RecyclerView.Adapter的内容，您需要在适配器中定义接口并在Activity中实现该接口。

例如，这里是一个应用程序的代码，该应用程序将单击的项目的字符串及其位置发送到显示它的新活动：

MainActivity：

public class MainActivity extends AppCompatActivity implements MyAdapter.CallbackInterface {


    private static final int MY_REQUEST = 1001;

    private static final String [] ITEMS = {"Item 1", "Item 2", "Item 3" ,"Item 4", "Item 5", "Item 6"};

    private MyAdapter myAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // ... Adapter setup, simple LinearLayoutManager and String [] used
        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.rec_view);
        myAdapter = new MyAdapter(this, ITEMS);
        recyclerView.setHasFixedSize(true);
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        recyclerView.setAdapter(myAdapter);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch(resultCode){

            case RESULT_OK:

                // ... Check for some data from the intent
                if(requestCode == MY_REQUEST){
                    // .. lets toast again
                    int position = -1;
                    if(data != null){
                        position = data.getIntExtra("Position", 0);
                    }

                    if(position != -1) {
                        Toast.makeText(this, "Handled the result successfully at position " + position, Toast.LENGTH_SHORT).show();
                    }else{
                        Toast.makeText(this, "Failed to get data from intent" , Toast.LENGTH_SHORT).show();
                    }
                }

                break;

            case RESULT_CANCELED:

                // ... Handle this situation
                break;
        }
    }

    /**
     * Interface Method which communicates to the Acitivty here from the {@link MyAdapter}
     * @param position - the position
     * @param text - the text to pass back
     */
    @Override
    public void onHandleSelection(int position, String text) {

        Toast.makeText(this, "Selected item in list "+ position + " with text "+ text, Toast.LENGTH_SHORT).show();

        // ... Start a new Activity here and pass the values
        Intent secondActivity = new Intent(MainActivity.this, DetailActivity.class);
        secondActivity.putExtra("Text",text);
        secondActivity.putExtra("Position", position);
        startActivityForResult(secondActivity, MY_REQUEST);
    }
}

MainActivity的xml：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.divshark.recyclerviewsimpledemo.MainActivity">

    <android.support.v7.widget.RecyclerView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/rec_view" />
</RelativeLayout>

MyAdapter：

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyHolder>{

    private CallbackInterface mCallback;
    private String [] mMyItems;
    private Context mContext;

    public interface CallbackInterface{

        /**
         * Callback invoked when clicked
         * @param position - the position
         * @param text - the text to pass back
         */
        void onHandleSelection(int position, String text);
    }

    public MyAdapter(Context context, String [] myItems){

        mContext = context;
        mMyItems = myItems;

        // .. Attach the interface
        try{
            mCallback = (CallbackInterface) context;
        }catch(ClassCastException ex){
            //.. should log the error or throw and exception
            Log.e("MyAdapter","Must implement the CallbackInterface in the Activity", ex);
        }
    }

    @Override
    public int getItemCount() {
        return mMyItems.length;
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public void onBindViewHolder(MyHolder holder, final int position) {

        // Set the text for the View
        holder.mTextView.setText(mMyItems[position]);

        // Use your listener to pass back the data
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                if(mCallback != null){
                    mCallback.onHandleSelection(position, mMyItems[position]);
                }
            }
        });
    }

    @Override
    public MyHolder onCreateViewHolder(ViewGroup parent, int viewType) {

        View view = LayoutInflater.from(mContext).inflate(R.layout.list_item, parent, false);
        return new MyHolder(view);
    }

    static class MyHolder extends RecyclerView.ViewHolder{

        TextView mTextView;

        public MyHolder(View itemView) {
            super(itemView);

            mTextView = (TextView) itemView.findViewById(R.id.tv_list_item);
        }
    }
}

适配器的布局：

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

    <TextView
        android:id="@+id/tv_list_item"
        android:textColor="@android:color/black"
        tools:text="Some Text Holder"
        android:layout_marginLeft="16dp"
        android:textSize="18sp"
        android:layout_centerVertical="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</RelativeLayout>

和DetailActivity：

public class DetailActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.detail_activity);

        TextView textView = (TextView) findViewById(R.id.tv_detail_text);

        if(getIntent() != null && getIntent().getExtras() != null) {
            Bundle extras = getIntent().getExtras();
            String text = extras.getString("Text");
            int position = extras.getInt("Position");

            textView.setText(String.format("%s at position %d", text, position));

            // .. For this purpose set result okay and use position as part of data when Activity finishes
            // Which will in turn invoke the onActivityResult method in the calling activity
            Intent resultIntent = new Intent();
            resultIntent.putExtra("Position", position);
            setResult(RESULT_OK, resultIntent);
        }
    }
}

详细活动的布局：

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


    <TextView
        android:id="@+id/tv_detail_text"
        android:layout_gravity="center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
</FrameLayout>

祝你好运，编码愉快！

Answer 2

另一种解决方案是在您启动RecyclerView / ListView的活动类中设置onActivityResult方法。这也有效，除了某些原因我在尝试使用意图传递数据时遇到NPE错误，因此work-arround就是创建静态String / Int并改变它在点击和访问上的价值。这很好用。但是上面的答案也很好，而且它的表现也很好，甚至可能更好。

适配器类中的super.onActivityResult？ Android的

2 个答案: