android - RecyclerView 和 CardView Click 监听器实现

Question

我刚进入 android RecyclerView 和 CardViewand ... 并意识到 recyclerview 没有 Onclick listner 的选项，但在实现此功能后，我只是看不到任何结果。

听到的是我的代码和布局:

主要 Activity :

public class MainActivity extends AppCompatActivity {

    //private usefulSites_RecyclerView_Adapter mAdapter;
    final Context context = this;
    private RecyclerView mRecyclerView;
    private StaggeredGridLayoutManager mGridLayoutManager;
    private RecyclerViewAdapter mAdapter;
    private String[] mList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar mToolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(mToolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);
        mToolbar.setNavigationOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                onBackPressed();
            }
        });
        //使用CollapsingToolbarLayout必须把title设置到CollapsingToolbarLayout上，设置到Toolbar上则不会显示
        CollapsingToolbarLayout mCollapsingToolbarLayout = (CollapsingToolbarLayout) findViewById(R.id.collapsing_toolbar_layout);
        mCollapsingToolbarLayout.setTitle("test");
        //通过CollapsingToolbarLayout修改字体颜色
        mCollapsingToolbarLayout.setExpandedTitleColor(Color.WHITE);//设置还没收缩时状态下字体颜色
        mCollapsingToolbarLayout.setCollapsedTitleTextColor(Color.GREEN);


        //mList = getResources().getStringArray(R.array.numbers);

        mRecyclerView = (RecyclerView) findViewById(R.id.recyclerView);
        mGridLayoutManager = new StaggeredGridLayoutManager(1, StaggeredGridLayoutManager.VERTICAL);
        mRecyclerView.setItemAnimator(new DefaultItemAnimator());
        mRecyclerView.setLayoutManager(mGridLayoutManager);
        mAdapter = new RecyclerViewAdapter(getApplicationContext());
        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);
    }
}

RecyclerViewAdapter

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

    private Context mContext;
    private String [] mSiteTitle,mSiteLink;
    private int [] mThumbnail;

    public RecyclerViewAdapter(Context contexts, String[] list) {
        this.mContext = contexts;
        this.mSiteTitle = list;
    }
    public RecyclerViewAdapter(Context contexts) {
        this.mContext = contexts;
        initList();
    }
    private void initList(){

        UsfulSite_init mInit=new UsfulSite_init();
        mSiteTitle= mInit.initSiteTitle();
        mSiteLink=mInit.initSiteLink();
        mThumbnail=mInit.initThumbnail();


    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        LayoutInflater inflater = LayoutInflater.from(parent.getContext());
        View itemView = inflater.inflate(R.layout.usful_sites_card_view, parent, false);
        return new ViewHolder(itemView);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.sTitle.setText(mSiteTitle[position]);
        holder.sLink.setText(mSiteTitle[position]);
        holder.sImage.setImageResource(mThumbnail[position]);


        holder.setClickListener(new ItemClickListener() {
            @Override
            public void onClick(View view, int position, boolean isLongClick) {
                if (isLongClick) {
                    Toast.makeText(mContext, "#" + position + " - " + mSiteTitle[position] + " (Long click)", Toast.LENGTH_SHORT).show();
                } else {
                    Toast.makeText(mContext, "#" + position + " - " + mSiteTitle[position], Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

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

    public static class ViewHolder extends RecyclerView.ViewHolder
            implements View.OnClickListener, View.OnLongClickListener{
        private TextView sTitle,sLink;
        private ImageView sImage;
        private ItemClickListener clickListener;

        public ViewHolder(View itemView) {
            super(itemView);
            sTitle = (TextView)itemView.findViewById(R.id.useful_sites_Title);
            sLink=(TextView)itemView.findViewById(R.id.useful_sites_Link);
            sImage=(ImageView)itemView.findViewById(R.id.useful_sites_thumbnail);
            itemView.setTag(itemView);
            itemView.setOnClickListener(this);
            itemView.setOnLongClickListener(this);


        }

        public void setClickListener(ItemClickListener itemClickListener) {
            this.clickListener = itemClickListener;
        }

        @Override
        public void onClick(View view) {
            clickListener.onClick(view, getPosition(), false);
        }

        @Override
        public boolean onLongClick(View view) {
            clickListener.onClick(view, getPosition(), true);
            return true;
        }
    }
}

Activity_main.xml:

<android.support.design.widget.CoordinatorLayout
android:id="@+id/coordinatorLayout"

xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<android.support.design.widget.AppBarLayout

    android:layout_width="match_parent"
    android:layout_height="256dp"
    android:fitsSystemWindows="true">
    <android.support.design.widget.CollapsingToolbarLayout
        android:id="@+id/collapsing_toolbar_layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"

        app:contentScrim="#30469b"
        app:expandedTitleMarginStart="48dp"
        app:layout_scrollFlags="scroll|exitUntilCollapsed">
        <ImageView

            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scaleType="centerCrop"
            android:src="@drawable/a"
            app:layout_collapseMode="parallax"
            app:layout_collapseParallaxMultiplier="0.7"  />
        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_collapseMode="pin" />
    </android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="none" />
</LinearLayout>

CardView Layout.xml:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="horizontal" android:layout_width="match_parent"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:layout_margin="5dp"
card_view:cardCornerRadius="5dp"
card_view:cardElevation="4dp"
android:layout_height="match_parent">

<RelativeLayout

    android:id="@+id/mainHolder"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ImageView
        android:id="@+id/useful_sites_thumbnail"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:scaleType="centerCrop"
        android:tint="@color/photo_tint"
        android:layout_centerInParent="true"
        />

    <TextView
        android:id="@+id/useful_sites_Title"
        android:gravity="center"
        android:background="?android:selectableItemBackground"
        android:focusable="true"
        android:clickable="true"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:textSize="24sp"
        android:layout_centerInParent="true"
        android:textColor="@android:color/white"
        />
    <TextView
        android:id="@+id/useful_sites_Link"
        android:gravity="center"
        android:background="?android:selectableItemBackground"
        android:focusable="true"
        android:clickable="true"
        android:layout_width="match_parent"
        android:layout_height="100dp"
        android:textSize="24sp"
        android:layout_centerInParent="true"
        android:textColor="@android:color/white"
        android:visibility="gone"
        />
</RelativeLayout>

我在 RV 中为 clickListner 测试了另一种方法，但我只是坚持这一点。有人可以看一下我的代码并指导我吗？关于这一点。

Answer 1

如果你想为每个 cardview 实现 onClick，你可以这样做:在您的 XML 中:

<android.support.v7.widget.CardView
    android:id="@+id/card_view">

    ...

</android.support.v7.widget.CardView>

然后，在您的适配器代码中:

public static class ViewHolder extends RecyclerView.ViewHolder {
        private CardView cardView;

        public ViewHolder(View itemView) {
            super(itemView);
            cardView = (CardView) itemView.findViewById(R.id.card_view);
        }
}

...

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    holder.cardView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                //implement onClick
                System.out.println("Clicked");
            }
        });
    }
}