Java 更新View.OnClick中的RecyclerView的最佳实践是什么？

不确定解决这个问题的最佳方法。我有一个

RecyclerView

，它表示数据库中的记录列表（我使用的是SugarOrm；但是，这与问题无关）

我希望表示数据更改，并允许用户通过

onClick

和

onLongClick

事件执行CRUD功能。例如，如果用户长按了

RecyclerView

中的视图，我希望他们可以选择删除记录。问题在于，仅使用

视图持有者

，更新很容易反映在视图中；但是，删除记录并不是那么容易。

ViewHolder

作为一个静态内部类，无权访问

RecyclerView

本身来修改适配器数据或通知数据已更改

一个选项是，我可以使内部的

ViewHolder

类不是静态的；但是，我应该担心潜在的内存泄漏吗？感觉这将是最简单的解决方案；但是，我是否应该使用完全不同的模式（例如让另一个类成为

onClickListener

）

我希望尽可能保持代码可读性和标准实践；但是，如果它将违反最佳实践或变得效率低下，就不会这样做

请参见下面的说明

要在ViewHolder中显示的SugarOrm模型类：

public class SomeModel extends SugarRecord{

    @Column(name="Name")
    public String name;
    @Column(name="AddedDate")
    public Date addedDate = new Date();
}

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

    private List<SomeModel> data;

    public SomeModelRecyclerViewAdapter(List<SomeModel> data) {
        this.data = data;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.model_item, parent, false);
        ViewHolder holder = new ViewHolder(view);
        view.setOnClickListener(holder);
        view.setOnLongClickListener(holder);
        return holder;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.someModel = data.get(position);
        holder.bindData();
    }

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

    public static class ViewHolder extends RecyclerView.ViewHolder
    implements View.OnClickListener, View.OnLongClickListener {

        private static final SimpleDateFormat dateFormat =
                new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");

        SomeModel someModel;
        TextView modelNameLabel;
        TextView modelDateLabel;

        public SomeModel getSomeModel() {
            return someModel;
        }

        public void setSomeModel(SomeModel someModel) {
            this.someModel = someModel;
        }


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

        public void bindData() {
            modelNameLabel = (TextView) itemView.findViewById(R.id.modelNameLabel);
            modelDateLabel = (TextView) itemView.findViewById(R.id.modelDateLabel);
            modelNameLabel.setText(someModel.name);
            modelDateLabel.setText(dateFormat.format(someModel.addedDate));
        }

        @Override
        public void onClick(View v) {
            someModel.addedDate = new Date();
            someModel.save();
            bindData();
        }

        @Override
        public boolean onLongClick(View v) {
            someModel.delete();
            return true;
        }
    }
}

<?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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.aaronmbond.recyclerviewdilemaexample.MainActivity">

    <EditText
        android:id="@+id/modelName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        />

    <Button
        android:id="@+id/addModelButton"
        android:layout_alignParentStart="true"
        android:layout_below="@id/modelName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/addModelButtonText"
        />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/modelList"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/addModelButton"
        android:layout_alignParentStart="true"
        />

</RelativeLayout>

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

    <TextView
        android:id="@+id/modelNameLabel"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />
    <TextView
        android:id="@+id/modelDateLabel"
        android:layout_alignParentStart="true"
        android:layout_below="@id/modelNameLabel"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />

</RelativeLayout>

RecycleServiceAdapter和ViewHolder：

public class SomeModel extends SugarRecord{

    @Column(name="Name")
    public String name;
    @Column(name="AddedDate")
    public Date addedDate = new Date();
}

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

    private List<SomeModel> data;

    public SomeModelRecyclerViewAdapter(List<SomeModel> data) {
        this.data = data;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.model_item, parent, false);
        ViewHolder holder = new ViewHolder(view);
        view.setOnClickListener(holder);
        view.setOnLongClickListener(holder);
        return holder;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.someModel = data.get(position);
        holder.bindData();
    }

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

    public static class ViewHolder extends RecyclerView.ViewHolder
    implements View.OnClickListener, View.OnLongClickListener {

        private static final SimpleDateFormat dateFormat =
                new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");

        SomeModel someModel;
        TextView modelNameLabel;
        TextView modelDateLabel;

        public SomeModel getSomeModel() {
            return someModel;
        }

        public void setSomeModel(SomeModel someModel) {
            this.someModel = someModel;
        }


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

        public void bindData() {
            modelNameLabel = (TextView) itemView.findViewById(R.id.modelNameLabel);
            modelDateLabel = (TextView) itemView.findViewById(R.id.modelDateLabel);
            modelNameLabel.setText(someModel.name);
            modelDateLabel.setText(dateFormat.format(someModel.addedDate));
        }

        @Override
        public void onClick(View v) {
            someModel.addedDate = new Date();
            someModel.save();
            bindData();
        }

        @Override
        public boolean onLongClick(View v) {
            someModel.delete();
            return true;
        }
    }
}

<?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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.aaronmbond.recyclerviewdilemaexample.MainActivity">

    <EditText
        android:id="@+id/modelName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        />

    <Button
        android:id="@+id/addModelButton"
        android:layout_alignParentStart="true"
        android:layout_below="@id/modelName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/addModelButtonText"
        />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/modelList"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/addModelButton"
        android:layout_alignParentStart="true"
        />

</RelativeLayout>

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

    <TextView
        android:id="@+id/modelNameLabel"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />
    <TextView
        android:id="@+id/modelDateLabel"
        android:layout_alignParentStart="true"
        android:layout_below="@id/modelNameLabel"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />

</RelativeLayout>

回收视图项目布局（

model\u Item.xml

）：

public class SomeModel extends SugarRecord{

    @Column(name="Name")
    public String name;
    @Column(name="AddedDate")
    public Date addedDate = new Date();
}

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

    private List<SomeModel> data;

    public SomeModelRecyclerViewAdapter(List<SomeModel> data) {
        this.data = data;
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.model_item, parent, false);
        ViewHolder holder = new ViewHolder(view);
        view.setOnClickListener(holder);
        view.setOnLongClickListener(holder);
        return holder;
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.someModel = data.get(position);
        holder.bindData();
    }

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

    public static class ViewHolder extends RecyclerView.ViewHolder
    implements View.OnClickListener, View.OnLongClickListener {

        private static final SimpleDateFormat dateFormat =
                new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");

        SomeModel someModel;
        TextView modelNameLabel;
        TextView modelDateLabel;

        public SomeModel getSomeModel() {
            return someModel;
        }

        public void setSomeModel(SomeModel someModel) {
            this.someModel = someModel;
        }


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

        public void bindData() {
            modelNameLabel = (TextView) itemView.findViewById(R.id.modelNameLabel);
            modelDateLabel = (TextView) itemView.findViewById(R.id.modelDateLabel);
            modelNameLabel.setText(someModel.name);
            modelDateLabel.setText(dateFormat.format(someModel.addedDate));
        }

        @Override
        public void onClick(View v) {
            someModel.addedDate = new Date();
            someModel.save();
            bindData();
        }

        @Override
        public boolean onLongClick(View v) {
            someModel.delete();
            return true;
        }
    }
}

<?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:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.aaronmbond.recyclerviewdilemaexample.MainActivity">

    <EditText
        android:id="@+id/modelName"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        />

    <Button
        android:id="@+id/addModelButton"
        android:layout_alignParentStart="true"
        android:layout_below="@id/modelName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/addModelButtonText"
        />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/modelList"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/addModelButton"
        android:layout_alignParentStart="true"
        />

</RelativeLayout>

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

    <TextView
        android:id="@+id/modelNameLabel"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />
    <TextView
        android:id="@+id/modelDateLabel"
        android:layout_alignParentStart="true"
        android:layout_below="@id/modelNameLabel"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        />

</RelativeLayout>

---

几天前，我遇到了类似的要求。您对部件的看法是正确的-

ViewHolder作为一个静态内部类，无权访问RecyclerView本身来修改适配器数据或通知数据已更改。

因此，处理这个问题的方法是定义一个接口，该接口封装了viewholder中的所有操作，它需要在RecyclerView上触发某些操作。我的代码中的示例接口定义-

/**
 * Parent fragment or activity to implement this interface to listen to item deletes.
 * Item deletes effect the state of the parent
 */
public interface OnItemModifiedListener {
    void itemDeleted(Cart.CartItem item);
    void itemQuantityChanged(Cart.CartItem item, int newQuantity);
    void itemRemovedAll();
}

父片段或活动实现此接口，并将其作为其构造函数的一部分传递给适配器。再次使用我的代码中的示例构造函数-

public SimpleItemRecyclerViewAdapter(Context context, List<Cart.CartItem> items, OnItemModifiedListener l) {

    //this variable is declared as a adapter state variable
    mItemModifiedListener = l;

}

下面的链接也是一个很好的阅读-

---

希望这有助于……

谢谢！此解决方案在保持轻量级的同时工作得很好！