Question

这篇文章与此ViewHolder not working有关。在该帖子中，我正在关注如何在ViewHolder上使用ListView的教程。我现在想要的是让ListView上的最后一个项目具有与其余项目不同的布局。这是我的代码：

int lastpos = mList.size()-1;
          System.out.println("position: "+position+" mlist: "+lastpos);

          if(position==lastpos){
           view = vi.inflate(R.layout.list_item_record, null);
           holder.textView = (TextView)view.findViewById(R.id.record_view);
          }else{
           view = vi.inflate(R.layout.list_item_bn, null);
           holder.textView = (TextView)view.findViewById(R.id.tv_name);
          }
          view.setTag(holder);

我只是得到ListView大小减去1并且有条件检查当前位置是否等于最后一项。但是，此代码将最后一个项目的布局设置为与其余项目相同。 getView方法完整代码：

private class CustomListAdapter extends ArrayAdapter { 
    private ArrayList mList;
    private Context mContext;

    public CustomListAdapter(Context context, int textViewResourceId,
            ArrayList list) {
        super(context, textViewResourceId, list);
        this.mList = list;
        this.mContext = context;
    }   

    public View getView(final int position, View convertView, ViewGroup parent) {
        View view = convertView;

        final ToggleButton tb;

         if (view == null) {
          ViewHolder holder = new ViewHolder();
          LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

          int lastpos = mList.size()-1;
          System.out.println("position: "+position+" mlist: "+lastpos);

          if(position==lastpos){
           view = vi.inflate(R.layout.list_item_record, null);
           holder.textView = (TextView)view.findViewById(R.id.record_view);
          }else{
           view = vi.inflate(R.layout.list_item_bn, null);
           holder.textView = (TextView)view.findViewById(R.id.tv_name);
          }
          view.setTag(holder);
         }

         final ItemsDisplay listItem = (ItemsDisplay) mList.get(position);
            if (listItem != null) {
             ViewHolder holder1 = (ViewHolder)view.getTag();
             holder1.textView.setText(listItem.getTag());

             view.setOnClickListener(new OnClickListener() {
                    public void onClick(View arg0) { //--clickOnListItem
                     Toast.makeText(getBaseContext(),
                       "Button is "+position+" "+listItem.getTag(),
                       Toast.LENGTH_LONG).show();
                    }
                });

                tb  = (ToggleButton) view.findViewById(R.id.toggleButton);
                tb.setOnClickListener(new View.OnClickListener() {
              public void onClick(View v) {

               if(tb.isChecked()){
                Toast.makeText(getBaseContext(),
                           "Button is "+position+" checked:"+tb.isChecked()+" "+listItem.getTag(),
                           Toast.LENGTH_LONG).show();
               }else{
                Toast.makeText(getBaseContext(),
                  "Button is "+position+" checked:"+tb.isChecked()+" "+listItem.getTag(),
                           Toast.LENGTH_LONG).show();
               }
              }
                });
            }



        return view;  
    }

}

有人可以帮我吗？

Answer 1

为您的适配器实施getItemViewType()和getViewTypeCount()：

@Override
public int getViewTypeCount() {
   return 2; //return 2, you have two types that the getView() method will return, normal(0) and for the last row(1)
}

和：

@Override
public int getItemViewType(int position) {
    return (position == this.getCount() - 1) ? 1 : 0; //if we are at the last position then return 1, for any other position return 0
}

然后在getView()方法中找出要膨胀的视图类型：

public View getView(final int position, View convertView, ViewGroup parent) {
        View view = convertView;
        int theType = getItemViewType(position); 
        if (view == null) {
          ViewHolder holder = new ViewHolder();
          LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
          if (theType == 0) {
              // inflate the ordinary row
              view = vi.inflate(R.layout.list_item_bn, null);
              holder.textView = (TextView)view.findViewById(R.id.tv_name);      
          } else if (theType == 1){
             // inflate the row for the last position
              view = vi.inflate(R.layout.list_item_record, null);
              holder.textView = (TextView)view.findViewById(R.id.record_view);
          } 
          view.setTag(holder);
         }
 //other stuff here, keep in mind that you have a different layout for your last position so double check what are trying to initialize
}

评论中的示例：http://pastebin.com/gn65240B（或https://gist.github.com/2641914）

Answer 2

问题是，一旦你给视图充气，它可以在任何位置重复使用多次。我建议采用以下方法：您像往常一样（包括视图持有者）对所有项目进行充气（包括视图持有者），但对于最后一项，您将引用保存为CustomListAdapter的字段，并在每次最后一项时返回请求：

private class CustomListAdapter extends ArrayAdapter { 
    ...
    private View mLastItem; 

    public View getView(final int position, View convertView, ViewGroup parent) {
        View view = convertView;
        ...
        int lastpos = mList.size()-1;

        if (view == null) {
            ViewHolder holder = new ViewHolder();
            LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);

            if (position == lastpos) {
                view = vi.inflate(R.layout.list_item_record, null);
                holder.textView = (TextView)view.findViewById(R.id.record_view);
                mLastItem = view;
            }
            else {
                view = vi.inflate(R.layout.list_item_bn, null);
                holder.textView = (TextView)view.findViewById(R.id.tv_name);
            }
            view.setTag(holder);
        }

        if (position == lastpos) {
            ... // Update the last item here
            return mLastItem; 
        }
        ...
    }

}

ListView中的不同行布局

2 个答案: