如何在 Recycler View android 中显示带界面的卡片视图？

Question

我想在 recyclerview 中使用 Cardview 并且需要它在列表位置在 android java

的任何 class 中的点击事件

Answer 1

步骤 - 1 - 在主Activity布局中添加 Recyclerview

<?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"
    tools:context=".MainActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/idRVCourse"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</RelativeLayout>

步骤 - 2 - 对于我们的卡片，我们在这里创建新的资源文件 - layout -> new -> LayoutResourceFile -> New Layout Name / Here i give card_layout

<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_margin="5dp"
    app:cardBackgroundColor="@color/white"
    app:cardCornerRadius="8dp"
    app:cardElevation="8dp"
    app:cardMaxElevation="10dp"
    app:cardPreventCornerOverlap="true"
    app:cardUseCompatPadding="true">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content">

        <ImageView
            android:id="@+id/idIVCourseImage"
            android:layout_width="100dp"
            android:layout_height="100dp"
            android:layout_marginStart="10dp"
            android:layout_marginTop="10dp"
            android:layout_marginEnd="10dp"
            android:layout_marginBottom="10dp"
            android:contentDescription="@string/app_name"
            android:padding="5dp"
            android:src="@color/black" />

        <TextView
            android:id="@+id/idTVCourseName"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginStart="10dp"
            android:layout_marginTop="10dp"
            android:layout_toEndOf="@id/idIVCourseImage"
            android:text="course_name"
            android:textColor="@color/black"
            android:textSize="18sp"
            android:textStyle="bold" />

    </RelativeLayout>
</androidx.cardview.widget.CardView>

步骤 - 3 - 现在我们必须为 Model/Item 创建一个 class，我在这里创建名为 CourseModel

的新 class

public class CourseModel {

    private String course_name;
    private int course_image;

    // Constructor
    public CourseModel(String course_name, int course_image) {
        this.course_name = course_name;
        this.course_image = course_image;
    }

    public String getCourse_name() {
        return course_name;
    }

    public void setCourse_name(String course_name) {
        this.course_name = course_name;
    }

    public int getCourse_image() {
        return course_image;
    }

    public void setCourse_image(int course_image) {
        this.course_image = course_image;
    }
}

步骤 - 4 - 这里我们必须创建新的 Class 作为适配器，我在这里命名为 CourseAdapter

public class CourseAdapter extends RecyclerView.Adapter<CourseAdapter.Viewholder> {

    private Context context;
    private ArrayList<CourseModel> courseModelArrayList;
    // i3 create interface variable & add in constructor & solve main activity error by pass this in new CourseAdapter
    OnItemClickListener onItemClickListener;
    CourseModel item;

    public CourseAdapter(Context context, ArrayList<CourseModel> courseModelArrayList, OnItemClickListener onItemClickListener) {
        this.context = context;
        this.courseModelArrayList = courseModelArrayList;
        this.onItemClickListener = onItemClickListener;
    }

    @NonNull
    @Override
    public CourseAdapter.Viewholder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_layout, parent, false);
        return new Viewholder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull CourseAdapter.Viewholder holder, int position) {

        CourseModel model = courseModelArrayList.get(position);

        holder.courseNameTV.setText(model.getCourse_name());
        holder.courseIV.setImageResource(model.getCourse_image());
        // can also set click event from Adapter class
        /*holder.courseIV.setOnClickListener(v -> {
            Toast.makeText(context, " -> "+model.getCourse_name(), Toast.LENGTH_SHORT).show();
        });*/
    }

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

    public class Viewholder extends RecyclerView.ViewHolder {
        private ImageView courseIV;
        private TextView courseNameTV;

        public Viewholder(@NonNull View itemView) {
            super(itemView);
            courseIV = itemView.findViewById(R.id.idIVCourseImage);
            courseNameTV = itemView.findViewById(R.id.idTVCourseName);

            // i5
            itemView.setOnClickListener(view -> {
                onItemClickListener.onItemClick(item,getAdapterPosition());
                notifyDataSetChanged();
            });
        }
    }
}

步骤 - 5 - 现在让我们在这里创建界面，我按名称创建界面 OnItemClickListener

// I1
public interface OnItemClickListener {
    void onItemClick(CourseModel item, int position);
    void onLongItemClick(CourseModel item, int position);
}

步骤 - 6 - 在最后一步中，在 Main 中应用下面的代码 Activity 在 ItemList 中，您可以放置 Drawble 的图像

// i2 implement interface & solve error
public class MainActivity extends AppCompatActivity implements OnItemClickListener{

    private RecyclerView courseRV;

    private ArrayList<CourseModel> courseItemList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        courseRV = findViewById(R.id.idRVCourse);

        itemList();
        
        // i4
        CourseAdapter courseAdapter = new CourseAdapter(this, courseItemList,this);

        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false);

        courseRV.setLayoutManager(linearLayoutManager);
        courseRV.setAdapter(courseAdapter);
    }

    private void itemList() {
        courseItemList = new ArrayList<>();
        courseItemList.add(new CourseModel("C",  R.drawable.ic_launcher_background));
        courseItemList.add(new CourseModel("C++",  R.drawable.ic_launcher_background));
        courseItemList.add(new CourseModel("Java",  R.drawable.ic_launcher_background));
        courseItemList.add(new CourseModel("Android",  R.drawable.ic_launcher_background));
        courseItemList.add(new CourseModel("Flutter", R.drawable.ic_launcher_background));
        courseItemList.add(new CourseModel("HTML",  R.drawable.ic_launcher_background));
        courseItemList.add(new CourseModel("CSS",  R.drawable.ic_launcher_background));
    }

    // i6
    @Override
    public void onItemClick(CourseModel item, int position) {
        Toast.makeText(this, ""+position+"\n"+courseItemList.get(position).getCourse_name(), Toast.LENGTH_SHORT).show();
    }

    @Override
    public void onLongItemClick(CourseModel item, int position) {

    }
}

如何在 Recycler View android 中显示带界面的卡片视图？

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