Question

我正在尝试在我的recyclerView中使用Spinner（带有下拉菜单的3个点），但是当我加载此recyclerView函数时，会自动调用 onItemSelected 函数，以后再按该项目时，它将不再调用。这是我在适配器中的代码：

       @Override
       public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
            ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(context, R.array.my_listing_item_array, android.R.layout.simple_spinner_item);
            adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
            ((SaleAdapter.SalesViewHolder) holder).overflow.setAdapter(adapter);

            ((SaleAdapter.SalesViewHolder) holder).overflow.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
                @Override
                public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
                    Toast.makeText(context, String.valueOf(position) + " item is selected", Toast.LENGTH_SHORT).show();
                }

                @Override
                public void onNothingSelected(AdapterView<?> adapterView) {

                }
            });

}

  public static class SalesViewHolder extends RecyclerView.ViewHolder {
      public LinearLayout overflowLayout;
      public Spinner overflow;

      public SalesViewHolder(View itemView, Context context) {
          super(itemView);

          overflowLayout = (LinearLayout) itemView.findViewById(R.id.list_item_overflow_layout);
          overflow = (Spinner) itemView.findViewById(R.id.list_item_overflow);
      }
     }

这是View的代码：

<LinearLayout
    android:id="@+id/list_item_overflow_layout"
    android:layout_width="54dp"
    android:layout_height="54dp"
    android:layout_gravity="center_vertical"
    android:orientation="vertical"
    android:padding="15dp"
    android:background="@drawable/ic_more_vert_24dp_grey"
    >

    <Spinner
        android:id="@+id/list_item_overflow"
        android:layout_width="24dp"
        android:layout_height="24dp"
        />


</LinearLayout>

有人知道我的代码在这里出什么问题吗？我应该在其他地方导出 setOnItemSelectedListener 吗？

Answer 1

对于列表中的每个项目，最好使用PopUpMenu。使用ImageView代替Spinner，它将显示“ 3点”图标。当有人单击圆点时，PopUpMenu将...弹出！

步骤：

1）用Spinner替换xml布局中的ImageView，这将显示三个点图标。

2）在RecyclerView.Adapter<SalesViewHolder>内定义一个侦听器类，并在其中保存一个实例。

3）在SalesViewHolder内设置一个OnClickListener来响应点击。

4）从活动中弹出。

您的新适配器应如下所示

class SalesAdapter extends RecyclerView.Adapter<SalesViewHolder>{
    public interface OnMenuItemClickListener{
        void onMenuItemClicked(ImageView view);
    }

    private OnMenuItemClickListener listener;

    public void setOnMenuItemClickListener(OnMenuItemClickListener listener){
        this.listener = listener;
    }

    public static class SalesViewHolder extends RecyclerView.ViewHolder {
        public LinearLayout overflowLayout;
        public ImageView menu;

    public SalesViewHolder(View itemView, Context context) {
        super(itemView);

        overflowLayout = (LinearLayout) itemView.findViewById(R.id.list_item_overflow_layout);
        menu= (ImageView) itemView.findViewById(R.id.imageview_id);
        // Make sure to enable lambdas
        menu.setOnClickListener( (view) -> {
            if( listener != null ){
                listener.onMenuItemClicked(view);
            }
        }
    }
     }

}

您的活动必须实现OnMenuItemClickListener，并且可能看起来像这样

class YourActivity extends Activity implements SalesAdapter.OnMenuItemClickListener{

    // Don't forget to set the listener to the adapter,  let's suppose that happens in onCreate()
    @Override
    public void onCreate(Bundle arg){
        SalesAdapter adapter = new SalesAdapter();
        adapter.setOnMenuItemClickListener(this);
    }

    @Override
    public void onMenuItemClicked(ImageView menu){
        showPopUp(menu);
    }

    private void showPopup(View v) {
        PopupMenu popup = new PopupMenu(this, v);
        MenuInflater inflater = popup.getMenuInflater();
        inflater.inflate(R.menu.actions, popup.getMenu());
        popup.show();
    }

}

别忘了提供菜单操作等...，如here所述。

recyclerView中的android Spinner无法正常工作

1 个答案: