RecyclerView onListItemClick创建新意图

Question

所以，在最新更新之前，我使用onListItemClick监听器并且它工作正常，但现在我尝试使用RecyclerView，并且我不确定如何为每个项目实现onClick，这将打开一个新活动。

这就是我以前拥有的

public class SermonsFragment extends Fragment {

    @Override
    public void onListItemClick(ListView list, View v, int position, long id) {
        Intent mediaStreamIntent = new Intent(getActivity(), MediaStreamPlayer.class);
        mediaStreamIntent.putExtra("sermon_details", (android.os.Parcelable) list.getItemAtPosition(position));
        startActivity(mediaStreamIntent);
    }
}

但是现在，我没有使用listview而是创建了一个布道适配器，它看起来像这个

public class SermonListAdapter extends RecyclerView.Adapter<SermonListAdapter.ViewHolder>{
    private ArrayList<Sermon> mDataset;

    // Provide a reference to the views for each data item
    // Complex data items may need more than one view per item, and
    // you provide access to all the views for a data item in a view holder
    //Note: need to remove static class no idea why
    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
        // each data item is just a string in this case
        public View mView;
        public ViewHolder(View v) {
            super(v);
            v.setOnClickListener(this);
            mView = v;
        }

        @Override
        public void onClick(View v) {
            Log.d("SermonsListAdapter.java.debug", "itemClick " + mDataset.get(getPosition()).getName());

        }
    }

    // Provide a suitable constructor (depends on the kind of dataset)
    public SermonListAdapter(ArrayList<Sermon> myDataset) {
        mDataset = myDataset;
    }

    // Create new views (invoked by the layout manager)
    @Override
    public SermonListAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
                                                   int viewType) {
        // create a new view
        View v = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.sermon_cardview, parent, false);
        // set the view's size, margins, paddings and layout parameters

        ViewHolder vh = new ViewHolder(v);
        return vh;
    }

    // Replace the contents of a view (invoked by the layout manager)
    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        // - get element from your dataset at this position
        // - replace the contents of the view with that element
        TextView title = (TextView) holder.mView.findViewById(R.id.sermon_title);
        TextView series = (TextView) holder.mView.findViewById(R.id.sermon_series);
        TextView pastor = (TextView) holder.mView.findViewById(R.id.sermon_pastor);
        TextView sermonDate = (TextView) holder.mView.findViewById(R.id.sermon_date);

        title.setText(mDataset.get(position).getName());
        series.setText(mDataset.get(position).getSeries());
        pastor.setText(mDataset.get(position).getPastor());
        sermonDate.setText(mDataset.get(position).getSermonDate());

    }

并且片段或多或少相同，它只是我不能再使用onListItemClick

    public class SermonsFragment extends Fragment {
        private static final int MAX_SERMONS_LIST = 20;
        private ArrayAdapter<Sermon> listAdapter;
        private String imageUrl;
        private static String sermonListJSONUrl = “http://someurl”;

        private RecyclerView mRecyclerView;
        private RecyclerView.Adapter mAdapter;
        private RecyclerView.LayoutManager mLayoutManager;

        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setRetainInstance(true);

            //Check if there is internet, if yes call JSONParser
            ConnectionDetector myConnection = new ConnectionDetector(getActivity().getApplicationContext());
            Boolean isInternetOnline = false;
            isInternetOnline = myConnection.isConnectingToInternet();

            if(isInternetOnline) {
                //Call JSONParser Asynchronously to get sermonList in JSON Format
                new callJSONParserAsync().execute(sermonListJSONUrl);
            }
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_sermons, container, false);
            mRecyclerView = (RecyclerView) rootView.findViewById(R.id.my_recycler_view);
            return rootView;
        }

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

            mLayoutManager = new LinearLayoutManager(getActivity());
            mRecyclerView.setLayoutManager(mLayoutManager);
            mRecyclerView.setItemAnimator(new DefaultItemAnimator());

            //Just an Empty Class
            ArrayList<Sermon> mySermon = new ArrayList<Sermon>();

            //specify an adapter
            mAdapter = new SermonListAdapter(mySermon);
            mRecyclerView.setAdapter(mAdapter);
        }

我的cardview xml看起来像这样

<!-- A CardView that contains a TextView -->
<android.support.v7.widget.CardView
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    android:id="@+id/card_view"
    android:layout_margin="5dp"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    card_view:cardCornerRadius="1dp">

    <LinearLayout android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceLarge"
            android:id="@+id/sermon_title" />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceSmall"
            android:id="@+id/sermon_series" />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceSmall"
            android:id="@+id/sermon_pastor" />
        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textAppearance="?android:attr/textAppearanceSmall"
            android:id="@+id/sermon_date" />
    </LinearLayout>
</android.support.v7.widget.CardView>

我在尝试创建新意图

时遇到此错误

12-18 22:31:48.469  31887-31887/org.ifgfseattle.ifgfseattle E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: org.ifgfseattle.ifgfseattle, PID: 31887
    android.util.AndroidRuntimeException: Calling startActivity() from outside of an Activity  context requires the FLAG_ACTIVITY_NEW_TASK flag. Is this really what you want?
            at android.app.ContextImpl.startActivity(ContextImpl.java:1232)
            at android.app.ContextImpl.startActivity(ContextImpl.java:1219)
            at android.content.ContextWrapper.startActivity(ContextWrapper.java:322)
            at org.ifgfseattle.ifgfseattle.adapter.SermonListAdapter$1.onClick(SermonListAdapter.java:81)
            at android.view.View.performClick(View.java:4756)
            at android.view.View$PerformClick.run(View.java:19749)
            at android.os.Handler.handleCallback(Handler.java:739)
            at android.os.Handler.dispatchMessage(Handler.java:95)
            at android.os.Looper.loop(Looper.java:135)
            at android.app.ActivityThread.main(ActivityThread.java:5221)
            at java.lang.reflect.Method.invoke(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:372)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:899)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:694)

Answer 1

您可以在adpater内的onClick方法中对视图实施onBindViewHolder。

1. 将ID分配给包含项目单元格的视图
2. 以文字视图的方式获取视图

3. 将onClick设置为方法内的root，如下所示：

   @Override
   public void onBindViewHolder(ViewHolder holder, int position) {
       viewHolder.relLayout.setOnClickListener(new OnClickListener(){
           public void onClick(View v) {
                // perform your operations here 
           }
       });
   }
   

修改

这是你在xml中分配id的方法

<LinearLayout android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:id="@+id/lnrLayout"  ---------->> This is new
    android:orientation="vertical">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceLarge"
        android:id="@+id/sermon_title" />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:id="@+id/sermon_series" />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:id="@+id/sermon_pastor" />
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textAppearance="?android:attr/textAppearanceSmall"
        android:id="@+id/sermon_date" />
</LinearLayout>

这是您定义视图（或可能实例化它们）的方式

public ViewHolder(View mView) {
        super(view);
        title = (TextView) holder.mView.findViewById(R.id.sermon_title);
        series = (TextView) holder.mView.findViewById(R.id.sermon_series);
        pastor = (TextView) holder.mView.findViewById(R.id.sermon_pastor);
        sermonDate = (TextView) holder.mView.findViewById(R.id.sermon_date)
        lnrLayout = (LinearLayout)holder.mView.findViewById(R.id.lnrLayout);
    }

这是你的自定义视图，所以声明TextViews就像我们声明变量一样..你的onBindView方法现在看起来像这样：

 @Override
public void onBindViewHolder(ViewHolder holder, int position) {
    holder.title.setText(mDataset.get(position).getName());
    holder.series.setText(mDataset.get(position).getSeries());
    holder.pastor.setText(mDataset.get(position).getPastor());
    holder.sermonDate.setText(mDataset.get(position).getSermonDate());
    holder.lnrLayout.setOnClickListener(new OnClickListener(){
          public void onClick(View v) {
             // on click action here
             //-- use context to start the new Activity
            Intent mediaStreamIntent = new Intent(mContext, MediaStreamPlayer.class);
            mediaStreamIntent.putExtra("sermon_details", (android.os.Parcelable) mDataset.get(position));
            mContext.startActivity(mediaStreamIntent);
          }
    });
}

我真的不知道为什么两者之间存在差异，可能是因为你正在初始化onbind而不是viewholder构造函数。

您也可以参考this

编辑2 :(第二种方法）

将适配器更改为以下内容：

// Provide a suitable constructor (depends on the kind of dataset)
public SermonListAdapter(ArrayList<Sermon> myDataset, Fragment fragment) {
    mDataset = myDataset;
    mFragment = fragment;
}

在onClick上执行此操作：

if(mFragment != null && mFragment instanceof SermonFragment) {
      ((SermonFragment)mFragment).sendToNextActivity(position); -> you can pass any data you wsh to
 }

在fragment类中创建一个名为sendToNextAcitivity且具有相同param定义的公共方法，然后调用下一个intent。

第三种方法

在适配器中创建接口，为接口创建set方法，在片段中实现接口，然后初始化它，然后将其传递给适配器的set方法。

然后使用它：

if(mListener!= null) {
         mListener.sendToNextActivity(position); -> you can pass any data you wsh to
     }