技術標籤：Android

大家好，我是OB！
這是Android的UI系列之ListView、RecyclerView

一：ListView

列表佈局

  protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list_view);
        initData();
        ListView listView = findViewById(R.id.my_listview)
 
;
        listView.setAdapter(new MyAdapter(dataArray,this));
}

設定Adapter

class MyAdapter extends BaseAdapter {
    ArrayList arrayList = null;
    Context context;
    MyAdapter(ArrayList arrayList, Context context) {
        this.arrayList = arrayList;
        this.context = context;
    }
    @Override
 

    public int getCount() {
        return arrayList.size();
    }

    @Override
    public Object getItem(int position) {
        return arrayList.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public int getItemViewType
 
(int position) {
        if (position % 2 == 0) {
            return 0;
        } else {
            return 1;
        }
    }

    @Override
    public int getViewTypeCount() {
        return 2;
    }
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {

        Log.d("TAG", "getCount: "+arrayList.size());
        MyHolderOne holderOne;
        MyHolderTwo holderTwo;
        if (convertView == null) {
            if (getItemViewType(position) == 1) {
                convertView = LayoutInflater.from(context).inflate(R.layout.cell, parent, false);
                holderOne = new MyHolderOne();
                holderOne.textView = (TextView)convertView.findViewById(R.id.title_name);
                convertView.setTag(R.id.title_name,holderOne);
                holderOne.textView.setText((String)arrayList.get(position));
            }  else {
                convertView = LayoutInflater.from(context).inflate(R.layout.cell_header, parent, false);

                holderTwo = new MyHolderTwo();
                holderTwo.textView = (TextView)convertView.findViewById(R.id.title_header);
                convertView.setTag(R.id.title_header,holderTwo);
                holderTwo.textView.setText((String)arrayList.get(position));
            }

        } else {
            if (getItemViewType(position) == 1) {
                holderOne = (MyHolderOne) convertView.getTag(R.id.title_name);
                holderOne.textView.setText((String)arrayList.get(position));
            }  else {
                holderTwo = (MyHolderTwo) convertView.getTag(R.id.title_header);
                holderTwo.textView.setText((String)arrayList.get(position));
            }
        }
        return convertView;

    }
class MyHolderOne {
    TextView textView;
}

class MyHolderTwo {
    TextView textView;
}
}
    

getItemViewType的返回值必須從 0 開始，不然會陣列越界，當返回多個型別的item時，getItemViewType()和getViewTypeCount()必須實現

二：RecyclerView

RecyclerView常用的佈局分三種

// 線性佈局 --類似於ListView
recyclerView.setLayoutManager(new LinearLayoutManager(this, RecyclerView.VERTICAL,false));
// 網格佈局 --瀑布流佈局
recyclerView.setLayoutManager(new GridLayoutManager(this, 3));
// 錯落網格佈局 --瀑布流佈局
recyclerView.setLayoutManager(new 
StaggeredGridLayoutManager(3,RecyclerView.VERTICAL));

這也是StaggeredGridLayoutManager

public class OBRecycleViewActivity extends AppCompatActivity {
    ArrayList dataArray;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_o_b_recycle_view);
        initData();
        RecyclerView recyclerView = findViewById(R.id.ob_recyclerveiw);

		// 線性佈局 --類似於ListView
        recyclerView.setLayoutManager(new LinearLayoutManager(this, RecyclerView.VERTICAL,false));
        // 網格佈局 --瀑布流佈局
        recyclerView.setLayoutManager(new GridLayoutManager(this, 3));
        // 錯落網格佈局 --瀑布流佈局
        recyclerView.setLayoutManager(new StaggeredGridLayoutManager(3,RecyclerView.VERTICAL));

        recyclerView.setAdapter(new OBRecyclerAdapter(dataArray, this));
        // 水平方向分割線
        recyclerView.addItemDecoration(new DividerItemDecoration(this,RecyclerView.HORIZONTAL));
        // 豎直方向分割線 
        recyclerView.addItemDecoration(new DividerItemDecoration(this,RecyclerView.VERTICAL));
    }

    private void initData () {
        dataArray = new ArrayList<String>();
        dataArray.add("ListView");
        dataArray.add("RecycleView");
        dataArray.add("ViewPager");
        // ....
    }


    private class OBRecyclerAdapter extends RecyclerView.Adapter {
        ArrayList datas;
        Context context;
        OBRecyclerAdapter(ArrayList datas, Context context) {
            this.datas = datas;
            this.context = context;
        }

        @NonNull
        @Override
        public RecyclerView.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
            if (viewType == 0) {
                View v =  LayoutInflater.from(context).inflate(R.layout.rv_cell_header, parent, false);
                RVHolderHeader rvHolder = new RVHolderHeader(v);
                rvHolder.textView = v.findViewById(R.id.header_tv);
                return rvHolder;
            } else  {
                View v =  LayoutInflater.from(context).inflate(R.layout.recycler_view_cell, parent, false);
                RVHolder rvHolder = new RVHolder(v);
                rvHolder.textView = v.findViewById(R.id.content_tv);
                return rvHolder;
            }

        }

        @Override
        public int getItemViewType(int position) {
            if (position % 2 == 0){
                return 0;
            } else  {
                return 1;
            }
        }

        @Override
        public void onBindViewHolder(@NonNull RecyclerView.ViewHolder holder, int position) {
            if (holder.getClass() == RVHolderHeader.class) {
                RVHolderHeader header = (RVHolderHeader) holder;
                header.textView.setText((String) datas.get(position));
            } else  {
                RVHolder rvHolder = (RVHolder) holder;
                rvHolder.textView.setText((String) datas.get(position));
            }
        }

        @Override
        public int getItemCount() {
            return datas==null?0:datas.size();
        }

    }
    private class RVHolderHeader extends RecyclerView.ViewHolder {

        TextView textView;
        public RVHolderHeader(@NonNull View itemView) {
            super(itemView);
        }
    }
    private class RVHolder extends RecyclerView.ViewHolder {

        TextView textView;
        public RVHolder(@NonNull View itemView) {
            super(itemView);
        }
    }
}

其中adapter.notifyDataSetChanged();可以用來更新資料