Android

Question

问题： 在 recyclerview

中长按某个项目时，无法显示显示 "delete" 选项的上下文菜单

预期结果：见下图

我快完成了，但是我缺少使上下文菜单显示在长按上的东西。

这是我放在 viewHolder 中的内容。我不知道应该添加什么以及在 onLongClick 事件中在哪里显示上下文菜单。

我跳过了一些代码行并保留了与我的问题相关的代码行。

非常感谢您的协助，

我的界面处理两种类型的点击

public interface OnItemClickListener{
    void onItemClick(int position);
}

public interface OnItemLongClickListener{
    void onItemLongClick(int position);
}

取景代码

public void bindLongClick(final int position, final OnItemLongClickListener onItemLongClickListener) {
        itemView.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View view) {
                onItemLongClickListener.onItemLongClick(position);
                return true;
            }
        });
    }

    @Override
    public void onCreateContextMenu(ContextMenu contextMenu, View view, ContextMenu.ContextMenuInfo contextMenuInfo){
            //menuInfo is null
        Log.v(LOG_TAG, "grrr");
        contextMenu.setHeaderTitle("Select The Action");
        contextMenu.add(0, view.getId(), 0, "Supprimer");//groupId, itemId, order, title
    }

适配器代码

@Override
    public void onBindViewHolder(CityListViewholder holder, int position) {
        holder.cityName.setText(cityArrayList.get(position).getCityName());
        holder.bindClick(position, onItemClickListener);
        holder.bindLongClick(position, onItemLongClickListener);
    }

然后，在 activity - 我跳过了与我的问题无关的内容

mCityListAdapter = new CityListAdapter(mContext, cityArrayList, new CityListAdapter.OnItemClickListener() {
            @Override
            public void onItemClick(int position) {
                mPager.setCurrentItem(position);
                mDrawerLayout.closeDrawers();
            }
        }, new CityListAdapter.OnItemLongClickListener() {
            @Override
            public void onItemLongClick(int position) {
                Log.v(LOG_TAG, "Position "+position);
            }
        });

        registerForContextMenu(mRecyclerView);

Answer 1

编辑 1：要专门显示对话框，请使用

 openContextMenu(v);

其中 v 指的是视图。和

@Override
public void onCreateContextMenu(ContextMenu menu, View v,
                                ContextMenu.ContextMenuInfo menuInfo) {
    super.onCreateContextMenu(menu, v, menuInfo);
    MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.context_menu,menu);
}
@Override
public boolean onContextItemSelected(MenuItem item) {
  int id = item.getItemId();
        default:
            return super.onContextItemSelected(item);
    }
}

菜单文件夹中 context_menu 文件中的代码应如下所示：

<menu 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"
    tools:context="com.example.MainActivity">

    <item
        android:id="@+id/item"
        android:orderInCategory="200"
        android:title="Item"
        android:icon="@drawable/faq"
        app:showAsAction="ifRoom"
        ></item>
</menu>

过去，我在使用 RecyclerView 的 onClickListener 和 onLongClickListener 时也遇到了一些问题。所以这是我正在使用的：

public class ItemClickSupport {
    private final RecyclerView mRecyclerView;
    private OnItemClickListener mOnItemClickListener;
    private OnItemLongClickListener mOnItemLongClickListener;
    private View.OnClickListener mOnClickListener = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            if (mOnItemClickListener != null) {
                RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
                mOnItemClickListener.onItemClicked(mRecyclerView, holder.getAdapterPosition(), v);
            }
        }
    };
    private View.OnLongClickListener mOnLongClickListener = new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            if (mOnItemLongClickListener != null) {
                RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
                return mOnItemLongClickListener.onItemLongClicked(mRecyclerView, holder.getAdapterPosition(), v);
            }
            return false;
        }
    };
    private RecyclerView.OnChildAttachStateChangeListener mAttachListener
            = new RecyclerView.OnChildAttachStateChangeListener() {
        @Override
        public void onChildViewAttachedToWindow(View view) {
            if (mOnItemClickListener != null) {
                view.setOnClickListener(mOnClickListener);
            }
            if (mOnItemLongClickListener != null) {
                view.setOnLongClickListener(mOnLongClickListener);
            }
        }

        @Override
        public void onChildViewDetachedFromWindow(View view) {

        }
    };

    private ItemClickSupport(RecyclerView recyclerView) {
        mRecyclerView = recyclerView;
        mRecyclerView.setTag(R.id.item_click_support, this);
        mRecyclerView.addOnChildAttachStateChangeListener(mAttachListener);
    }

    public static ItemClickSupport addTo(RecyclerView view) {
        ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
        if (support == null) {
            support = new ItemClickSupport(view);
        }
        return support;
    }

    public static ItemClickSupport removeFrom(RecyclerView view) {
        ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
        if (support != null) {
            support.detach(view);
        }
        return support;
    }

    public ItemClickSupport setOnItemClickListener(OnItemClickListener listener) {
        mOnItemClickListener = listener;
        return this;
    }

    public ItemClickSupport setOnItemLongClickListener(OnItemLongClickListener listener) {
        mOnItemLongClickListener = listener;
        return this;
    }

    private void detach(RecyclerView view) {
        view.removeOnChildAttachStateChangeListener(mAttachListener);
        view.setTag(R.id.item_click_support, null);
    }

    public interface OnItemClickListener {

        void onItemClicked(RecyclerView recyclerView, int position, View v);
    }

    public interface OnItemLongClickListener {

        boolean onItemLongClicked(RecyclerView recyclerView, int position, View v);
    }
}

然后在 activity 中使用以下内容：

ItemClickSupport.addTo(recyclerView).setOnItemLongClickListener(new ItemClickSupport.OnItemLongClickListener() {
            @Override
            public boolean onItemLongClicked(RecyclerView recyclerView, int position, View v) {

                return true;
            }
    });

使用position指定项目。希望对您有所帮助！

Answer 2

您需要的是显示带有列表的对话框。像这样：

    itemView.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View view) {
            final CharSequence[] items = {"Supprimer", "etc", "etc1"};

            AlertDialog.Builder builder = new AlertDialog.Builder(mContext);

            builder.setTitle("Select The Action");
            builder.setItems(items, new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int item) {
                }
            });
            builder.show();
            return true;
        }
    });

Answer 3

接受的答案在技术上不是 "the answer"，它是一个聪明的解决方法，因为它创建了一个 AlertDialog 而不是 OP 要求的 ContextMenu，它 "solve the requirement" 但它不会创建 ContextMenu.

这是我发现的最短的实现：

在 Activity 中，照常覆盖：

@Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
    menu.add("do this");
    menu.add("do that");
}

@Override
public boolean onContextItemSelected(MenuItem item) {
    if (item.getTitle().equals("do this") {
        // do whatever this...
    }
    else if (item.getTitle().equals("do that") {
        // do whatever that...
    }
    return super.onContextItemSelected(item);
}

在 RecyclerView 的项目 ViewHolder 中：

private class ItemViewHolder extends RecyclerView.ViewHolder {
    ...
    private ItemViewHolder(@NonNull View pItemView) {
        super(pItemView);
        pItemView.setLongClickable(true); // <-- make long clickable
        ...
    }
}

在 Activity onCreate:

registerForContextMenu(myRecyclerView);

Android - 长按 RecyclerView 项目和 ContextMenu

Android - Long Click on RecyclerView item and ContextMenu

contextmenu

android-recyclerview

这是我发现的最短的实现：

在 Activity 中，照常覆盖：

在 RecyclerView 的项目 ViewHolder 中：

在 Activity onCreate: