Android recyclerView - 如何知道我在哪個部分？

Question

我正在設計一個關於不同旅行方式的應用程序。所以我有一個Android的數據源，有許多不同類別的業務列表。類別是汽車，自行車和飛機。所以想象一張擁有多輛汽車的列表，其次是許多自行車，其次是許多飛機。我想用recyclerView將這些分開。但我不知道如何創建部分/類別？

我有一個模型（數據源），我可以打電話來獲得像這樣的每個類別： model.getAirplanesList（）; model.getCarsList（）; model.getBikesList（）;

有3種不同的型號會更好嗎？所以我需要最終產品先顯示：

1. list of airplanes 
    2. then a list of cars 
    3. last a list of bikes 

我需要它有每個部分的標題。我怎麼知道我在哪一節？

的3個類別將使用相同的佈局文件，使viewType可以保持不變我以爲：

@Override 
    public MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
     View itemView = LayoutInflater.from(parent.getContext()) 
       .inflate(R.layout.transports_list_row, parent, false); 

     return new MyViewHolder(itemView); 
    } 

//我應該以某種方式利用viewType？

，並在onBindViewHolder我很困惑，我怎麼能知道我在哪一部分到目前爲止，我只工作了飛機。

@Override 
    public void onBindViewHolder(MyViewHolder holder, int position) { 
     Transport transport = model.get(position).getAirplanesList(); 
     holder.title.setText(transport.getTitle()); 
     holder.genre.setText(transport.getGenre()); 
     holder.year.setText(transport.getYear()); 

//what about Cars and bikes. how to know what section i am in ? 
    } 

我希望我的數據通過像類/條訂購這樣的：

Answer 1

您可以使用庫SectionedRecyclerViewAdapter將數據分組爲段。

首先創建一個科類：

class MySection extends StatelessSection { 

    String title; 
    List<Transport> list; 

    public MySection(String title, List<Transport> list) { 
     // call constructor with layout resources for this Section header, footer and items 
     super(R.layout.section_header, R.layout.transports_list_row); 

     this.title = title; 
     this.list = list; 
    } 

    @Override 
    public int getContentItemsTotal() { 
     return list.size(); // number of items of this section 
    } 

    @Override 
    public RecyclerView.ViewHolder getItemViewHolder(View view) { 
     // return a custom instance of ViewHolder for the items of this section 
     return new MyItemViewHolder(view); 
    } 

    @Override 
    public void onBindItemViewHolder(RecyclerView.ViewHolder holder, int position) { 
     MyItemViewHolder itemHolder = (MyItemViewHolder) holder; 

     // bind your view here 
     Transport transport = list.get(position); 
     itemHolder.title.setText(transport.getTitle()); 
     itemHolder.genre.setText(transport.getGenre()); 
     itemHolder.year.setText(transport.getYear()); 
    } 

    @Override 
    public RecyclerView.ViewHolder getHeaderViewHolder(View view) { 
     return new SimpleHeaderViewHolder(view); 
    } 

    @Override 
    public void onBindHeaderViewHolder(RecyclerView.ViewHolder holder) { 
     MyHeaderViewHolder headerHolder = (MyHeaderViewHolder) holder; 

     // bind your header view here 
     headerHolder.tvItem.setText(title); 
    } 
} 

然後您設置RecyclerView與節：

// Create an instance of SectionedRecyclerViewAdapter 
SectionedRecyclerViewAdapter sectionAdapter = new SectionedRecyclerViewAdapter(); 

// Add your Sections to the adapter 
sectionAdapter.addSection(new MySection("Airplanes", model.getAirplanesList())); 
sectionAdapter.addSection(new MySection("Cars", model.getCarsList())); 
sectionAdapter.addSection(new MySection("Bikes", model.getBikesList())); 

// Set up your RecyclerView with the SectionedRecyclerViewAdapter 
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview); 
recyclerView.setLayoutManager(new LinearLayoutManager(getContext())); 
recyclerView.setAdapter(sectionAdapter); 

Answer 2

你在正確的軌道，你可以利用getItemViewType()找到ViewHolder類型應創建並在接下來的方法進行填充，基於對象類型或利弊traint。這意味着你可以有單獨的模型或只有一個模型並應用約束（小心，這不應該是繁重的操作），以返回正確的視圖類型。

簡單的檢查，通過約束類型：

@Override 
public int getItemViewType(int position){ 
    TransporationModel transportation = mList.get(position); 
    if(transporation.isBike()){ return VIEW_TYPE_BIKE; 
    else if(transporation.isBus()){ return VIEW_TYPE_BUSE; 
    //..etc 

}