android - 从 Activity 中隐藏 recyclerview 中的按钮，菜单不起作用

Question

尝试通过我的 Activity 菜单选项将按钮设置为在 recyclerview 中不可见，但它没有做任何事情我在 recyclerview 适配器和 bindviewholder 上创建了一个方法，我设置了 if 语句来更改可见性。我按照您调用方法的方式设置 Activity 。我错过了什么？谢谢

public class PostRecyclerAdapter extendsRecyclerView.Adapter<PostRecyclerAdapter.ViewHolder> {
private boolean activate = false;

public PostRecyclerAdapter(Context context, List<Post> blogList) {
    this.context = context;
    this.postList = blogList;
}

public PostRecyclerAdapter() {

}

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

    final int itemPos = position;
    final Post post = postList.get(position);
    holder.title.setText(post.getTitle());
    holder.desc.setText(post.getDesc());
    holder.category.setText(post.getTag());

    holder.edit.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            editClassifiedAd(post.getPostId());
        }
    });

    holder.delete.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            deleteClassifiedAd(post.getPostId(), itemPos);
        }
    });

    if (activate) {
        holder.edit.setVisibility(View.VISIBLE);
        holder.delete.setVisibility(View.VISIBLE);
    } else {
        holder.edit.setVisibility(View.INVISIBLE);
        holder.delete.setVisibility(View.INVISIBLE);
    }
}

public void activateButtons(boolean activate) {
    this.activate = activate;
    notifyDataSetChanged(); 
}


PostListActivity.java
public class PostListActivity extends AppCompatActivity{

PostRecyclerAdapter mAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_post_list);
    postListFrgmt();
    mAdapter = new PostRecyclerAdapter();

}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    getMenuInflater().inflate(R.menu.main_menu, menu);
    return super.onCreateOptionsMenu(menu);
}


@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case R.id.edit:
            if(item.isChecked()){
                // If item already checked then unchecked it
                item.setChecked(false);
                mAdapter.activateButtons(true);
            }else{
                // If item is unchecked then checked it
                item.setChecked(true);

                mAdapter.activateButtons(false);
            }

            return true;
        default:
            return super.onOptionsItemSelected(item);
    }

    return super.onOptionsItemSelected(item);
}

Answer 1

在 PostListActivity 中，您实际上并未将适配器设置为 RecyclerView。您需要添加您的 recyclerview，给它一个 LayoutManager(线性或其他方式)，然后将适配器传递给它。例如

//assuming you've declared the RecyclerView as recyclerView1
recylcerView1.setLayoutManager(new LinearLayoutManager(PostListActivity.this));
recylcerView1.setAdapter(mAdapter)