DataAdapter

Question

我正在尝试在一个RecyclerView中使用2种布局

我有一个称为Bookmark的回收站视图列表，它是从xml中解析出来的，并且都可以正常工作，但是我想在此回收站视图中放置另一个包含一个按钮且可以单击的布局。就像照片中的图标一样，图标来自recyclerview，加号按钮必须与列表兼容，如果列表较大或较小，则按钮将与列表空间兼容。

这是我的适配器新代码，具体取决于答案@LluisFelisart 这是错误 ViewHolder views must not be attached when created. Ensure that you are not passing 'true' to the attachToRoot parameter of LayoutInflater.inflate(..., boolean attachToRoot)

    public class MyAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private Context context;
    ArrayList<Bookmark> arrayList = new ArrayList<>();

    public MyAdapter(Context context, ArrayList<Bookmark> arrayList) {
        this.context = context;
        this.arrayList = arrayList;
    }

    public class ViewHolder0 extends RecyclerView.ViewHolder {

        TextView tvName,tvId,tvSearchUrl,tvNativeUrl;
        ImageView tvIcon;

        public ViewHolder0(@NonNull  View itemView) {
            super(itemView);

            tvName=itemView.findViewById(R.id.textView);
            tvIcon = itemView.findViewById(R.id.image_view);
         /*   tvId=itemView.findViewById(R.id.tvId);
            tvSearchUrl=itemView.findViewById(R.id.tvSearchUrl);
            tvNativeUrl=itemView.findViewById(R.id.tvNativeUrl);*/
        }
    }

    public class ViewHolder2 extends RecyclerView.ViewHolder {
        ImageView tvAddBookmark;

        public ViewHolder2(@NonNull View itemView) {
            super(itemView);
            tvAddBookmark = itemView.findViewById(R.id.image_button_add);
        }
    }
    @Override
    public int getItemViewType(int position) {
        // Just as an example, return 0 or 2 depending on position
        // Note that unlike in ListView adapters, types don't have to be contiguous
        return position % 2 * 2;
    }




    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int i) {
        View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.grid_item, viewGroup, false);

        switch (i) {
            case 0: return new ViewHolder0(viewGroup);
            case 2: return new ViewHolder2(viewGroup);
        }

        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
        switch (holder.getItemViewType()) {
            case 0:
                ViewHolder0 viewHolder0 = (ViewHolder0) holder;
                ((ViewHolder0) holder).tvName.setText(arrayList.get(position).getName());
                ((ViewHolder0) holder).tvIcon.setImageResource(arrayList.get(position).getIcon());
                break;

            case 2:
                ViewHolder2 viewHolder2 = (ViewHolder2) holder;

        }
        ((ViewHolder0) holder).tvIcon.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent;
                intent = new Intent(context, BookmarkActivity.class);
                v.getContext().startActivity(intent);
            }
        });

        ((ViewHolder0) holder).tvIcon.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                Intent intent = new Intent(context, ActivityBookmarksFavorites.class);
                v.getContext().startActivity(intent);
                return false;
            }
        });
    }




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

    public class ViewHolder extends RecyclerView.ViewHolder  {

        TextView tvName,tvId,tvSearchUrl,tvNativeUrl;
        ImageView tvIcon;

        public ViewHolder(@NonNull  View itemView) {
            super(itemView);

            tvName=itemView.findViewById(R.id.textView);
            tvIcon = itemView.findViewById(R.id.image_view);
         /*   tvId=itemView.findViewById(R.id.tvId);
            tvSearchUrl=itemView.findViewById(R.id.tvSearchUrl);
            tvNativeUrl=itemView.findViewById(R.id.tvNativeUrl);*/
        }



    }



}

这是网格项目的布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    android:orientation="vertical"
    android:visibility="visible"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    xmlns:android="http://schemas.android.com/apk/res/android">

    <ImageView
        android:id="@+id/image_view"
        style="@style/BookmarkIconIv" />
    <TextView android:id="@+id/textView"
        android:layout_marginTop="1.0dip"
        style="@style/BookmarkTextTv" />
</LinearLayout>

这是我想在回收器视图中显示的按钮的布局

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <ImageButton
        android:id="@+id/image_button_add"
        android:layout_width="45dp"
        android:layout_height="45dp"
        android:src="@drawable/ic_add_black_24dp"
        android:background="@color/transparent" />

</android.support.constraint.ConstraintLayout>

这是回收站视图中显示的片段

public class FragmentBookmark extends Fragment {
    ArrayList<Bookmark> arrayList = new ArrayList<>();
    XmlPullParser pullParser;
    MyAdapter myAdapter;
    View paramView;
    RecyclerView myRecyclerView;
    private Context mContext;
    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        mContext = context;
    }
    @Nullable
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
       paramView = inflater.inflate(R.layout.bookmark, container, false);

        myRecyclerView =  paramView.findViewById(R.id.myRecyclerView);
        myRecyclerView.setLayoutManager(new GridLayoutManager(mContext, 4));
        myRecyclerView.setHasFixedSize(true);
        myAdapter = new MyAdapter(mContext, arrayList);
        myRecyclerView.setAdapter(myAdapter);
        try {
            XmlPullParser xpp = getResources().getXml(R.xml.bookmarks);
            while (xpp.getEventType() != XmlPullParser.END_DOCUMENT) {
                if (xpp.getEventType() == XmlPullParser.START_TAG) {
                    if (xpp.getName().equals("Bookmark")) {
                        Bookmark bookmark = new Bookmark();
                        bookmark.setName(xpp.getAttributeValue(null, "name"));
                        int drawableResourceId = getResources().getIdentifier(xpp.getAttributeValue(null, "icon"),"drawable", mContext.getPackageName());
                        bookmark.setIcon(drawableResourceId);
                        arrayList.add(bookmark);
                    }
                }
                xpp.next();
            }
        } catch (XmlPullParserException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        myAdapter.notifyDataSetChanged();
        return paramView;
    }
    }

这是包含recyclerview的布局书签

<LinearLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:android="http://schemas.android.com/apk/res/android">
<android.support.v7.widget.RecyclerView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/myRecyclerView"
    android:layout_height="match_parent"
    android:orientation="horizontal"
    android:layout_width="match_parent"
    android:layout_marginBottom="8dp"
    android:layout_marginEnd="8dp"
    android:layout_marginStart="8dp"
    android:layout_marginTop="8dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    android:fillViewport="false">

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

</LinearLayout>

Answer 1

您可以在同一RecyclerView上使用不同的布局，只需重写适配器getItemViewType（）方法并为按钮布局返回不同的int值，在您的示例中，您应该为普通项目返回例如1，为2返回2按钮项。

视图类型作为参数传递给onCreateViewHolder()方法，并且根据viewType值，您可以为常规布局或按钮布局充气。

似乎您还需要使getItemCount()返回比数组大小多一个的值

希望这会有所帮助

这里是一个例子： How to create RecyclerView with multiple view type?

Answer 2

在“活动”中执行此操作。

        ArrayList<Bookmark>  data = new ArrayList<>();
        //data.addAll(your array list bookmark); uncomment this line add your all array list of bookmark
        Bookmark d = new Bookmark(0);
        data.add(d);
        mList.setAdapter(new BookMarkAdapter(activity, data));

尝试使用此适配器

public class BookMarkAdapter extends RecyclerView.Adapter {

private Context context;
private ArrayList<Bookmark> data;

public BookMarkAdapter(Context context, ArrayList<Bookmark> data) {
    this.context = context;
    this.data = data;
}

@NonNull
@Override
public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    if (viewType == 1)
        return new ViewBookmarkHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.cell_with_normal_image_and_textview, parent, false));
    else
        return new AddBookmarkHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.cell_with_image, parent, false));

}


@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {

    Bookmark d = data.get(position);

     if (d.getType()==1) {
        ViewBookmarkHolder viewBookmarkHolder =(ViewBookmarkHolder) holder;
        // do your show image and textview operation here
    } else {

        AddBookmarkHolder addBookmarkHolder =(AddBookmarkHolder) holder;
        // do your on click operation here. Like adding new bookmark and update your arraylist and notify data changed for adapter.
    }
}

@Override
public int getItemViewType(int position) {
    return data.get(position).getType();
}

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

在您的Bookmark Pojo中更新此方法和变量

public class Bookmark {

    private Integer type;

    public Bookmark(Integer type) {
        this.type = type;
    }

    public void setType(Integer type) {
        this.type = type;
    }

    public Integer getType() {
        if(type==null)
            return 1;
        return type;
    }
  }

Answer 3

这是答案

按照此步骤

首先为您的Multiple viewType创建两个布局

示例代码

layout.layout_one

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.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:orientation="vertical"
    app:cardCornerRadius="15dp"
    app:cardElevation="5dp"
    app:cardUseCompatPadding="true">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="Name  : " />

            <TextView
                android:id="@+id/tvName"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="" />

        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="Icon  : " />

            <ImageView
                android:id="@+id/tvIcon"
                android:layout_width="20dp"
                android:layout_height="20dp"
                android:padding="10dp"
                android:text="" />

        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="Id  : " />

            <TextView
                android:id="@+id/tvId"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="" />

        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="SearchUrl  : " />

            <TextView
                android:id="@+id/tvSearchUrl"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="" />

        </LinearLayout>

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal">

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="NativeUrl  : " />

            <TextView
                android:id="@+id/tvNativeUrl"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:padding="10dp"
                android:text="" />

        </LinearLayout>

    </LinearLayout>

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

layout.button_two

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

    <ImageView
        android:id="@+id/imgButton"
        android:layout_width="50dp"
        android:layout_height="50dp" />
</LinearLayout>

现在您需要为两个viewType创建两个`RecyclerView.ViewHolder`

现在您需要覆盖`getItemViewType()`

it返回该项目的viewType位置以用于视图回收。

现在，在您的 `onCreateViewHolder()` 方法中，您需要根据您的`ViewHolder`返回您的 `viewType` 实例使用`getItemViewType()`方法

比根据您的`onBindViewHolder()`设置视图属性的 `viewType` 方法

这是 RecyclerView.Adapter 的示例代码，具有多种视图类型

DataAdapter

import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.ArrayList;

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

    private Context context;
    ArrayList<Bookmark> arrayList = new ArrayList<>();
    public static final int ITEM_TYPE_ONE = 0;
    public static final int ITEM_TYPE_TWO = 1;

    public DataAdapter(Context context, ArrayList<Bookmark> arrayList) {
        this.context = context;
        this.arrayList = arrayList;
    }

    @NonNull
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        View view = null;
        // check here the viewType and return RecyclerView.ViewHolder based on view type
        if (viewType == ITEM_TYPE_ONE) {
            view = LayoutInflater.from(context).inflate(R.layout.layout_one, parent, false);
            return new ViewHolder(view);
        } else if (viewType == ITEM_TYPE_TWO) {
            view = LayoutInflater.from(context).inflate(R.layout.button_two, parent, false);
            return new ButtonViewHolder(view);
        }else {
            return  null;
        }

    }

    @Override
    public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {

        final int itemType = getItemViewType(position);
        // First check here the View Type
        // than set data based on View Type to your recyclerview item
        if (itemType == ITEM_TYPE_ONE) {
            ViewHolder viewHolder = (ViewHolder) holder;
            viewHolder.tvName.setText(arrayList.get(position).getName());
            viewHolder.tvIcon.setImageResource(arrayList.get(position).getIcon());
            viewHolder.tvSearchUrl.setText(arrayList.get(position).getSearchUrl());
            viewHolder.tvNativeUrl.setText(arrayList.get(position).getNativeUrl());
        } else if (itemType == ITEM_TYPE_TWO) {
            ButtonViewHolder buttonViewHolder = (ButtonViewHolder) holder;
            buttonViewHolder.imgButton.setImageResource(arrayList.get(position).getIcon());
        }

    }

    @Override
    public int getItemViewType(int position) {
        // based on you list you will return the ViewType 
        if (arrayList.get(position).getViewType() == 0) {
            return ITEM_TYPE_ONE;
        } else {
            return ITEM_TYPE_TWO;
        }
    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {

        TextView tvName, tvId, tvSearchUrl, tvNativeUrl;

        ImageView tvIcon;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);

            tvName = itemView.findViewById(R.id.tvName);
            tvIcon = itemView.findViewById(R.id.tvIcon);
            tvId = itemView.findViewById(R.id.tvId);
            tvSearchUrl = itemView.findViewById(R.id.tvSearchUrl);
            tvNativeUrl = itemView.findViewById(R.id.tvNativeUrl);
        }
    }

    public class ButtonViewHolder extends RecyclerView.ViewHolder {


        ImageView imgButton;

        public ButtonViewHolder(@NonNull View itemView) {
            super(itemView);

            imgButton = itemView.findViewById(R.id.imgButton);

        }
    }
}

在列表中添加数据时，您需要在列表中提供`viewtype`

在您的Bookmark POJO类中进行一些更改

Bookmark POJO类

public class Bookmark
{
    String name,id,nativeUrl,searchUrl;
    int icon;

    int viewType;

    public String getName() {
        return name;
    }

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

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public int getIcon() {
        return icon;
    }

    public void setIcon(int icon) {
        this.icon = icon;
    }

    public String getNativeUrl() {
        return nativeUrl;
    }

    public void setNativeUrl(String nativeUrl) {
        this.nativeUrl = nativeUrl;
    }

    public String getSearchUrl() {
        return searchUrl;
    }

    public void setSearchUrl(String searchUrl) {
        this.searchUrl = searchUrl;
    }

    public int getViewType() {
        return viewType;
    }

    public void setViewType(int viewType) {
        this.viewType = viewType;
    }

    @Override
    public String toString() {
        return "Bookmark{" +
                "name='" + name + '\'' +
                ", icon='" + icon + '\'' +
                ", id='" + id + '\'' +
                ", nativeUrl='" + nativeUrl + '\'' +
                ", searchUrl='" + searchUrl + '\'' +
                '}';
    }
}

示例活动代码

import android.content.Context;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;

import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

import java.io.IOException;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    private Context mContext;
    ArrayList<Bookmark> arrayList = new ArrayList<>();

    RecyclerView myRecyclerView;
    DataAdapter dataAdapter;

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


        mContext = this;

        myRecyclerView = findViewById(R.id.myRecyclerView);
        myRecyclerView.setLayoutManager(new LinearLayoutManager(mContext));
        myRecyclerView.setHasFixedSize(true);

        dataAdapter = new DataAdapter(mContext, arrayList);
        myRecyclerView.setAdapter(dataAdapter);

        try {

            XmlPullParser xpp = getResources().getXml(R.xml.bookmarks);

            while (xpp.getEventType() != XmlPullParser.END_DOCUMENT) {
                if (xpp.getEventType() == XmlPullParser.START_TAG) {
                    if (xpp.getName().equals("Bookmark")) {

                        Log.e("MY_VALUE", " * " + xpp.getAttributeValue(0) + " * ");
                        Log.e("MY_VALUE", " * " + xpp.getAttributeValue(1) + " * ");
                        Log.e("MY_VALUE", " * " + xpp.getAttributeValue(5) + " * ");
                        Log.e("MY_VALUE", " * " + xpp.getAttributeValue(2) + " * ");
                        Log.e("MY_VALUE", " * " + xpp.getAttributeValue(3) + " * ");
                        Log.e("MY_VALUE", " * " + xpp.getAttributeValue(4) + " * ");


                        Bookmark bookmark = new Bookmark();
                        bookmark.setName(xpp.getAttributeValue(0));

                        int drawableResourceId = this.getResources().getIdentifier(xpp.getAttributeValue(1), "drawable", mContext.getPackageName());
                        bookmark.setIcon(drawableResourceId);

                        bookmark.setId(xpp.getAttributeValue(2));

                        bookmark.setSearchUrl(xpp.getAttributeValue(3));
                        bookmark.setNativeUrl(xpp.getAttributeValue(4));

                        // here you need to set view type
                        bookmark.setViewType(0);
                        arrayList.add(bookmark);
                    }
                }

                xpp.next();
            }
        } catch (XmlPullParserException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }

        // here i have added second viewType
        // you need to set as per your requirement
        Bookmark bookmark = new Bookmark();
        bookmark.setViewType(1);
        bookmark.setIcon(R.drawable.dishu);
        arrayList.add(bookmark);
        dataAdapter.notifyDataSetChanged();

    }


}

注意

在下面的代码中，我在viewType的最后一个索引处设置了第二个Arraylist 您需要根据需要设置viewType

有关更多信息，您可以查看以下文章

从布局创建具有多个视图的RecyclerView

3 个答案:

首先为您的Multiple viewType创建两个布局

现在您需要为两个viewType创建两个`RecyclerView.ViewHolder`

现在您需要覆盖`getItemViewType()`

现在，在您的 `onCreateViewHolder()` 方法中，您需要根据您的`ViewHolder`返回您的 `viewType` 实例使用`getItemViewType()`方法

比根据您的`onBindViewHolder()`设置视图属性的 `viewType` 方法

DataAdapter

在列表中添加数据时，您需要在列表中提供`viewtype`

注意

从布局创建具有多个视图的RecyclerView

3 个答案:

首先为您的Multiple viewType创建两个布局

现在您需要为两个viewType创建两个RecyclerView.ViewHolder

现在您需要覆盖getItemViewType()

现在，在您的 onCreateViewHolder() 方法中，您需要根据您的ViewHolder返回您的 viewType 实例使用getItemViewType()方法

比根据您的onBindViewHolder()设置视图属性的 viewType 方法

DataAdapter

在列表中添加数据时，您需要在列表中提供viewtype

注意

现在您需要为两个viewType创建两个`RecyclerView.ViewHolder`

现在您需要覆盖`getItemViewType()`

现在，在您的 `onCreateViewHolder()` 方法中，您需要根据您的`ViewHolder`返回您的 `viewType` 实例使用`getItemViewType()`方法

比根据您的`onBindViewHolder()`设置视图属性的 `viewType` 方法

在列表中添加数据时，您需要在列表中提供`viewtype`