特定のビューホルダー私はコードの下に使用しますが、その誤りがあるホルダー

Question

見るにキャストカント： -

EventAdapter$MainViewHolder cannot be cast to EventAdapter$ProfileViewHolder

をしかし、各viewHolderは、MainViewHolderから問題は、このコードである を拡張しますか？

ありがとう、私はスタックオーバーフローの新人です！

public class NavDrawerAdapter extends RecyclerView.Adapter<NavDrawerAdapter.MainViewHolder> { 
List<MainOption> mainOptionlist; 
Context context; 
private static final int TYPE_PROFILE = 1; 
private static final int TYPE_OPTION_MENU = 2; 


public NavDrawerAdapter(Context context){ 
    this.mainOptionlist = MainOption.getDrawableDataList(); 
    this.context = context; 
} 

@Override 
public int getItemViewType(int position) { 
    return (position == 0? TYPE_PROFILE : TYPE_OPTION_MENU); 
} 

@Override 
public MainViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
    switch (viewType){} 
} 

@Override 
public void onBindViewHolder(MainViewHolder holder, int position) { 
    if(holder.getItemViewType() == TYPE_PROFILE){ 
     ProfileViewHolder mholder = (ProfileViewHolder) holder; 
    } 
    else { 
     MyViewHolder mHolder = (MyViewHolder) holder; 
     MainOption mo = mainOptionlist.get(position); 
     mHolder.tv_title.setText(mo.title); 
    } 
} 

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

public class MyViewHolder extends MainViewHolder{ 
    public MyViewHolder(View v){ 
     super(v); 
    } 
} 
public class ProfileViewHolder extends MainViewHolder{ 
    public ProfileViewHolder(View v){ 
     super(v); 
    } 
} 

public class MainViewHolder extends RecyclerView.ViewHolder { 
    public MainViewHolder(View v) { 
     super(v); 
    } 
} 

Answer 1

パブリッククラスChaptersAdapterはBaseAdapter {

private static final int TYPE_CHAPTER = 0; 
private static final int TYPE_PART = 1; 

private Context mContext; 
private ArrayList<Chapter> mChapters; 
private LayoutInflater mInflater; 
private ItemClickListener mItemClickListener; 
private TreeSet<Integer> mSectionNumber = new TreeSet<Integer>(); 
private boolean mIsPaid; 

public ChaptersAdapter(Context context, ArrayList<Chapter> chapters, ItemClickListener itemClickListener, boolean isPaid) { 
    mContext = context; 
    mChapters = chapters; 
    mItemClickListener = itemClickListener; 
    mInflater = LayoutInflater.from(context); 
    mIsPaid = isPaid; 
    saveSectionNum(); 
} 

@Override 
public int getCount() { 
    int n = 0; 
    for (int i = 0; i < mChapters.size(); i++) { 
     n += mChapters.get(i).mParts.size(); 
    } 
    n += mChapters.size(); 
    if (n < 0) 
     return 0; 
    return n; 
} 

private void saveSectionNum() { 
    int n = 0; 
    for (int i = 0; i < mChapters.size(); i++) { 
     mSectionNumber.add(n); 
     n += mChapters.get(i).mParts.size(); 
     n++; 
    } 
} 

private ChapterPart getChapterPart(int position) { 
    int n = 0; 
    int chapterNum = 0; 
    int partNum = -1; 

    while (n < position) { 
     n++; 
     n += mChapters.get(chapterNum).mParts.size(); 
     chapterNum++; 
    } 

    if (n > position) { 
     chapterNum--; 
     n = n - mChapters.get(chapterNum).mParts.size(); 
     partNum = position - n; 
    } else if (n == position) { 
     partNum = -1; 
    } 
    return new ChapterPart(chapterNum, partNum); 
} 

@Override 
public int getItemViewType(int position) { 
    return mSectionNumber.contains(position) ? TYPE_CHAPTER : TYPE_PART; 
} 

@Override 
public int getViewTypeCount() { 
    return 2; 
} 

@Override 
public Object getItem(int position) { 
    ChapterPart chapterPart = getChapterPart(position); 
    if (-1 == chapterPart.mPartNum) { 
     return mChapters.get(chapterPart.mChapterNum); 
    } 
    return mChapters.get(chapterPart.mChapterNum).mParts.get(chapterPart.mPartNum); 
} 

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

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 

    int rowType = getItemViewType(position); 

    if (convertView == null) { 

     switch (rowType) { 
      case TYPE_CHAPTER: 
       convertView = mInflater.inflate(R.layout.listitem_chapter, null); 
       ChapterTag tag1 = new ChapterTag(convertView); 
       convertView.setTag(tag1); 
       break; 
      case TYPE_PART: 
       convertView = mInflater.inflate(R.layout.listitem_part, null); 
       PartTag tag2 = new PartTag(convertView); 
       convertView.setTag(tag2); 
       break; 
     } 
    } 

    switch (rowType) { 
     case TYPE_CHAPTER: 
      ChapterTag tag1 = (ChapterTag)(convertView.getTag()); 
      Chapter chapter = (Chapter)getItem(position); 
      tag1.setData(position, chapter); 
      break; 
     case TYPE_PART: 
      PartTag tag2 = (PartTag)(convertView.getTag()); 
      Part part = (Part)getItem(position); 
      tag2.setData(position, part); 
      break; 
    } 
    return convertView; 

} 

class ChapterTag { 
    View view; 
    TextView txtChapter; 

    Chapter chapter; 

    public ChapterTag(final View view) { 
     this.view = view; 
     txtChapter = (TextView) view.findViewById(R.id.txt_chapter); 
    } 

    public void setData(int position, Chapter chapter) { 
     this.chapter = chapter; 
     txtChapter.setText(chapter.mName); 
    } 
} 

class PartTag { 
    View view; 
    TextView txtPart; 
    FancyButton btnVideo; 
    FancyButton btnAudio; 

    Part part; 

    public PartTag(final View view) { 
     this.view = view; 
     txtPart = (TextView) view.findViewById(R.id.txt_part); 

     btnVideo = (FancyButton) view.findViewById(R.id.btn_video); 

     UiUtil.applyButtonEffect(btnVideo, new Runnable() { 
      @Override 
      public void run() { 
       mItemClickListener.onVideoClick(part.mVideoURL); 
      } 
     }); 

     btnAudio = (FancyButton) view.findViewById(R.id.btn_audio); 

     UiUtil.applyButtonEffect(btnAudio, new Runnable() { 
      @Override 
      public void run() { 
       mItemClickListener.onAudioClick(part.mAudioURL); 
      } 
     }); 
    } 

    public void setData(int position, Part part) { 
     this.part = part; 
     txtPart.setText(part.mName); 
     if (part.mVideoURL.equals("")) { 
      btnVideo.setEnabled(false); 
     } 
     if (part.mAudioURL.equals("")) { 
      btnAudio.setEnabled(false); 
     } 
     ChapterPart chapterpart = getChapterPart(position); 
     if (position > 3 + chapterpart.mChapterNum && mIsPaid == false) { 
      btnVideo.setEnabled(false); 
      btnAudio.setEnabled(false); 
     } 
    } 
} 

class ChapterPart { 
    int mChapterNum; 
    int mPartNum; 

    ChapterPart(int chapterNum, int partNum) { 
     mChapterNum = chapterNum; 
     mPartNum = partNum; 
    } 
} 

}