ListView 中的分页存在于 ViewPager 中的三个不同片段中

Question

我遇到了 Pagination 的问题，该 ListView 存在于 **Each Fragment** 中，该 ViewPager 内。我最初必须在第一个 Fragment 中显示 10 条记录，即 “All”，由此整理出 “Failed” 并在第二个 Fragment 和 “Passed”中显示它 在第三个片段中。我该如何实现分页？我应该有一个 "Load More" 按钮，每当用户点击它时，我应该得到接下来的 10 条记录。我试图搜索，但找不到任何符合我目的的东西。请帮我。谢谢。

Answer 1

我不太了解“每个片段中都存在列表视图”。你的意思是显示的记录数是一样的吗？

那么如果第一个片段显示 10 条记录，其中 5 条失败，另外 5 条通过，那么第二个和第三个片段将只显示 5 条记录？

你不需要相同的 listView，我将指导你完成构建这个东西的过程。走吧！

我将假设获取记录不是问题，并且出于此答案的目的，我将假设记录是具有两个属性的对象：字符串内容和布尔值传递，可以由 isPassed() 和 getContent() 方法检索。

首先让我们处理调用片段的活动并添加几个重要的方法：

{...}
  private int listSize = 10;  

  public void addMoreToList(){
    listSize +=10;
  }

  public void getListSize(){
    return listSize;
  }

  //replace this method and all its implementations with your own way of getting the records
 public List<Record> getRecords(){
    return recordList;
   }

 
 {...}

好的，现在我们的主要活动可以存储和检索记录的数量，让我们来看看更大的枪，我们的适配器！

private class RecordAdapter extends BaseAdapter{
  
  public static final int MODE_ALL = 0;
  public static final int MODE_PASSED = 1;
  public static final int MODE_FAILED = 2;
  
  private int mode;
  private Context context;
  private List<Records> records;
  
  public RecordAdapter(Context context, int mode){
    this.context = context;
    this.mode = mode;
    }
  
  public void setData(List<Records> totalList, int size){
    //this will add from the records list the size we want
    //if that size is smaller than the total size of the list
    //or else we'd get an error :(
    for(int i = 0; i <  (totalList.size() < size ? size: totalList.size()); i++){
      switch(mode){
       case(MODE_ALL): 
        records.add(totalList.get(i))
        break;
       case(MODE_PASSED):
        if(totalLost.get(i).isPassed()){
          records.add(totalLost.get(i)
        }
        break;
       case(MODE_FAILED):
        if(!totalLost.get(i).isPassed()){
          records.add(totalLost.get(i));
        }
        break;
       }
     }
    notifyDatasetChanged(); //i almost forgot this one, heh, its very important.
   }
    
  @Override 
  public Object getItem(int position){
    return records.get(position)
  }
  
  @Override
  public int getCount(){
    return records.size();
  }
      
  @Override
  public int getItemId(int position){
    return position;
  }
  
  @Override
  public View getView(int position, View convertView, ViewGroup parent){
    View view;
    if(convertView == null){
      view =  LayoutInflater.from(context).inflate(R.layout.yourtextview, parent, false); //I'm assuming here you 
      //only want a textview to display the text
    }else{
      view = convertView;
    }
    
    TextView textView = (TextView) view.findViewById(R.id.yourtextview);
    Record record = records.get(position)
    textView.setText(record.getContent());
    
    return view;
 }
}

我们快到了！现在我们的片段。首先是xml：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
      <ListView
        android:id = "@+id/lv_records"
        android:layout_width = "match_parent"
        android:layout_height = "0 dp"           
        />
     
</LinearLayout>          

private RecordsAdapter adapter;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
  View view = inflater.inflate(R.layout.xmlabove, container, false);

  ListView listView = (ListView) view.findViewById(R.id.lv_records);
  

  //This is just an example. You can inflate a view from an xml if you want fancy format
  //and etc. You could also define an onClickListener directly in the button and add it
  //to the listView, but i think this design is more appropriate.
  Button button = new Button(getActivity());
  button.setText("Load more...");
  listView.addFooterView(button);
  listView.setOnItemClickListener(new AdapterView.OnItemClickListener(){
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id){
          if(position < ((RecordsAdapter) parent).getCount()){
            //code for regular record click here
          }else{
           //means the position is not in the adapter, it's our button
           ((YourActivityNameHere)getActivity()).addMoreToList();        
            adapter.setData(((YourActivityNameHere)getActivity()).getRecords(),    
                  ((YourActivityNameHere)getActivity()).getListSize());
          }
        }

  });
  adapter = new RecordsAdapter(context, RecordsAdapter.MODE_NORMAL); //replace each mode on each fragment
  
  adapter.setData(((YourActivityNameHere)getActivity()).getRecords(), ((YourActivityNameHere)getActivity()).getListSize());

  listView.setAdapter(adapter);
  
  return view; 

@Override
public void onResume(){
  super.onResume();
  //in case there was a change of listsize in another fragment, we want this adapter to update when we return
  //to this fragment.
  adapter.setData(((YourActivityNameHere)getActivity()).getRecords(), ((YourActivityNameHere)getActivity()).getListSize());
  }

毕竟你应该有一个你想要的功能实现！

另外，请记住，我只是在脑海中编写了所有这些代码，不知道，一些错误可能潜伏在代码中，因此请在使用之前阅读它。我现在真的无法重新阅读它。

希望我能有所帮助！