如何通过使用卡片在回收者视图中单击不同的卡片来打开不同的活动

Question

我创建了RecyclerView并添加了卡片。我想通过点击不同的卡片来打开不同的活动。

我的代码是：

MainActivity

public class MainActivity extends AppCompatActivity {
    RecyclerView mRecyclerView;
    RecyclerView.LayoutManager mLayoutManager;
    RecyclerView.Adapter mAdapter;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mRecyclerView = (RecyclerView)findViewById(R.id.recycler_view);
        mRecyclerView.setHasFixedSize(true);

        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);

        mAdapter = new CardAdapter();
        mRecyclerView.setAdapter(mAdapter); }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

CardAdapter

public class CardAdapter extends RecyclerView.Adapter<CardAdapter.ViewHolder> {

    List<NatureItem> mItems;

    public CardAdapter() {
        super();
        mItems = new ArrayList<NatureItem>();
        NatureItem nature = new NatureItem();
        nature.setName("The Great Barrier Reef");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);

        nature = new NatureItem();
        nature.setName("Grand Canyon");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);

        nature = new NatureItem();
        nature.setName("Baltoro Glacier");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);

        nature = new NatureItem();
        nature.setName("Iguazu Falls");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);


        nature = new NatureItem();
        nature.setName("Aurora Borealis");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View v = LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.recycler_view_card_item, viewGroup, false);
        ViewHolder viewHolder = new ViewHolder(v);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, int i) {
        NatureItem nature = mItems.get(i);
        viewHolder.tvNature.setText(nature.getName());
        viewHolder.tvDesNature.setText(nature.getDes());
        viewHolder.imgThumbnail.setImageResource(nature.getThumbnail());
    }

    @Override
    public int getItemCount() {
        return mItems.size();
    }

    class ViewHolder extends RecyclerView.ViewHolder {

        public ImageView imgThumbnail;
        public TextView tvNature;
        public TextView tvDesNature;

        public ViewHolder(View itemView) {
            super(itemView);
            imgThumbnail = (ImageView) itemView.findViewById(R.id.img_thumbnail);
            tvNature = (TextView) itemView.findViewById(R.id.tv_nature);
            tvDesNature = (TextView) itemView.findViewById(R.id.tv_des_nature);
        }
    }
}

NatureItem

public class NatureItem {
    private String mName;
    private String mDes;
    private int mThumbnail;

    public String getName() {
        return mName;
    }

    public void setName(String name) {
        this.mName = name;
    }

    public String getDes() {
        return mDes;
    }

    public void setDes(String des) {
        this.mDes = des;
    }

    public int getThumbnail() {
        return mThumbnail;
    }

    public void setThumbnail(int thumbnail) {
        this.mThumbnail = thumbnail;
    }
}

XML文件是正常的。 RecyclerView中的activity_main.xml和卡片视图中的一个xml

Answer 1

为每个＆＃34; Card＆＃34;创建监听器如指定here。

至于从不同的卡片中打开不同的活动，我会建议每张卡片（在这种情况下为＃34; NatureItem＆＃34;）来保持应该开始的活动的类别。

你可以这样做：

Intent intent = new Intent(context, nature.getClass());
context.startActivity(intent);

Answer 2

在适配器的ViewHolder类中添加以下内容：

public ViewHolder(View itemView) {
    super(itemView);
    .....
    .....

    itemView.setOnClickListener(new View.OnClickListener(){
         // Start your activity
    });
}

Answer 3

NatureItem .java

class NatureItem {
    private String name;
    private String des;
    private int setThumbnail;
    private int activityType; //1...n
    //its methods
    public int getActivityType(){
        return activityType;
    }

    public void setSetThumbnail(int setThumbnail) {
        this.setThumbnail = setThumbnail;
    }

    public void setActivityType(int activityType){
        this.activityType = activityType;
    }

    public void setName(String name) {
        this.name = name;
    }

    public void setDes(String des) {
        this.des = des;
    }

    public String getName() {
        return name;
    }

    public String getDes() {
        return des;
    }

    public int getThumbnail() {
        return setThumbnail;
    }
}

<强> ViewHolder.java

class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{

    public ImageView imgThumbnail;
    public TextView tvNature;
    public TextView tvDesNature;
    Callbacks callbacks;
    View itemView;
    public interface Callbacks{
        public void onItemSelect(View v,int position);
    }
    public ViewHolder(View itemView,Callbacks callbacks) {
        super(itemView);
        this.itemView = itemView;
        this.callbacks = callbacks;
        imgThumbnail = (ImageView) itemView.findViewById(R.id.img_thumbnail);
        tvNature = (TextView) itemView.findViewById(R.id.tv_nature);
        tvDesNature = (TextView) itemView.findViewById(R.id.tv_des_nature);
        itemView.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if(callbacks!=null){
            callbacks.onItemSelect(itemView,getAdapterPosition());
        }
    }
}

CardAdapter .java

class CardAdapter extends RecyclerView.Adapter<ViewHolder> {

    List<NatureItem> mItems;
    ViewHolder.Callbacks callbacks;

    public CardAdapter(ViewHolder.Callbacks callbacks) {
        super();
        this.callbacks = callbacks;
        mItems = new ArrayList<NatureItem>();
        NatureItem nature = new NatureItem();
        nature.setName("The Great Barrier Reef");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);

        nature = new NatureItem();
        nature.setName("Grand Canyon");
        nature.setActivityType(1); //activity type
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);

        nature = new NatureItem();
        nature.setName("Baltoro Glacier");
        nature.setActivityType(2);
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);

        nature = new NatureItem();
        nature.setName("Iguazu Falls");
        nature.setActivityType(3);
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);


        nature = new NatureItem();
        nature.setName("Aurora Borealis");
        nature.setDes("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt" +
                "ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud.");
        nature.setThumbnail(R.drawable.tag_logo);
        mItems.add(nature);
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        View v = LayoutInflater.from(viewGroup.getContext())
                .inflate(R.layout.recycler_view_card_item, viewGroup, false);
        ViewHolder viewHolder = new ViewHolder(v, callbacks);
        return viewHolder;
    }

    @Override
    public void onBindViewHolder(ViewHolder viewHolder, int i) {
        NatureItem nature = mItems.get(i);
        viewHolder.tvNature.setText(nature.getName());
        viewHolder.tvDesNature.setText(nature.getDes());
        viewHolder.imgThumbnail.setImageResource(nature.getThumbnail());
    }

    @Override
    public int getItemCount() {
        return mItems.size();
    }
    public NatureItem getItem(int pos){
        return mItems.get(pos);
    }
}

<强> MainActivity.java

class MainActivity extends AppCompatActivity implements ViewHolder.Callbacks{
    RecyclerView mRecyclerView;
    RecyclerView.LayoutManager mLayoutManager;
    CardAdapter mAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mRecyclerView = (RecyclerView) findViewById(R.id.recycler_view);
        mRecyclerView.setHasFixedSize(true);

        mLayoutManager = new LinearLayoutManager(this);
        mRecyclerView.setLayoutManager(mLayoutManager);

        mAdapter = new CardAdapter(this);
        mRecyclerView.setAdapter(mAdapter);
    }

    @Override
    public void onItemSelect(View v, int position) {
        NatureItem natureItem = mAdapter.getItem(position);
        if (natureItem.getActivityType() == 1) {
            //start this activity
        } else if (natureItem.getActivityType() == 2) {
            //start this activity
        }
    }
}