Question

我的主要活动有imageview，我想在点击它时创建一张新卡，我想管理它们。点击图片查看时如何添加卡片布局。这是我的cardview布局xml card_view.xml

<android.support.v7.widget.CardView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/cv"
    >

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:padding="16dp"
        >
        <TextView
            android:layout_width="300dp"
            android:layout_height="150dp"
            android:text="I'm here"
            android:id="@+id/textView"
            />
    </RelativeLayout>

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

卡片类只持有一个字符串

public class Card {
String information;
public void setInformation(String info)
{
    information=info;
}
public String getInformation()
{
    return information;
}

这是我的适配器

public class MyAdapter extends RecyclerView.Adapter<MyAdapter.MyViewHolder> {

private LayoutInflater inflater;
private List<Card> cards;

public MyAdapter (Context context,List<Card> cards)
{
    inflater=LayoutInflater.from(context);
    this.cards=cards;
}

@Override
public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view= inflater.inflate(R.layout.card_view,parent,false);
    MyViewHolder holder=new MyViewHolder(view);
    return holder;
}

@Override
public void onBindViewHolder(MyViewHolder holder, int position) {
    holder.textview.setText(cards.get(position).information);
}

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

public class MyViewHolder extends RecyclerView.ViewHolder
{
    TextView textview;
    CardView cardView;
    public MyViewHolder(View itemView) {
        super(itemView);
        textview=(TextView)itemView.findViewById(R.id.textView);
        cardView=(CardView)itemView.findViewById(R.id.cv);
    }
}

和主要

private MyAdapter adapter;
private List<Card> cards=new ArrayList<>();
private RecyclerView rv;
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    rv = (RecyclerView)findViewById(R.id.rv);
    rv.setHasFixedSize(true);

    final LinearLayoutManager llm=new LinearLayoutManager(getApplicationContext());
    rv.setLayoutManager(llm);

    final Card current=new Card();
    adapter=new MyAdapter(this,cards);
    rv.setAdapter(adapter);


    iView=(ImageView)findViewById(R.id.imageView);

    iView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            current.information="Hello";
            cards.add(current);

            //mLayout.addView();
                }
            });

Answer 1

当您更改在ListView或RecyclerView中使用的适配器的underling数据集时，必须调用适配器的notifyDataSetChanged()才能使更改生效。

因此，在代码中，您可以使用onClick()方法将卡片添加到卡片组中，然后调用notifyDataSetChanged()。所以改变这个：

public void onClick(View v) {
            current.information="Hello";
            cards.add(current);

            //mLayout.addView();
                }
            }

到此：

public void onClick(View v) {
            current.information="Hello";
            cards.add(current);
            adapter.notifyDataSetChanged();

            //mLayout.addView();
                }
            }

使用recyclerview创建一张卡片

1 个答案: