AndroidのGridViewでファイルフォルダを表示する方法は？

Question

アクティビティでGridViewに表示したいフォルダがたくさんあるディレクトリがあります。

フォルダとタイトルのパスを抽出しましたが、実装方法についてはGridViewに空白を示しています。 私のコードはGridViewの実装用です。

String[] albumNameOnly=thisIntent.getStringArrayExtra("AlbumString"); 
     gridView = (GridView) findViewById(R.id.grid_view); 
     columnWidth = getScreenWidth(); 
     InitilizeGridLayout(columnWidth); 
//The initialize grid is shown below. 
     MyAlbumAdapter myAlbumAdapter; 
     Log.e("Starting the Adapter","+++"); 
     myAlbumAdapter = new MyAlbumAdapter(getApplicationContext(), columnWidth,albumNameOnly); 
     gridView.setAdapter(myAlbumAdapter); 
    } 




public int getScreenWidth() { 
    int columnWidth; 
    WindowManager wm = (WindowManager) this.getSystemService(Context.WINDOW_SERVICE); 
    Display display = wm.getDefaultDisplay(); 

    final Point point = new Point(); 
    try { 
     display.getSize(point); 
    } catch (NoSuchMethodError ignore) { // Older device 
     point.x = display.getWidth(); 
     point.y = display.getHeight(); 
    } 
    columnWidth = point.x; 
    return columnWidth; 
} 




private void InitilizeGridLayout(int screenWidth) { 
    Resources r = getResources(); 
    float padding = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 
      GRID_PADDING, r.getDisplayMetrics()); 

    columnWidth = (int) ((screenWidth - ((NUM_OF_COLUMNS + 1) * padding))/NUM_OF_COLUMNS); 

    gridView.setNumColumns(NUM_OF_COLUMNS); 
    gridView.setColumnWidth(columnWidth); 
    gridView.setStretchMode(GridView.NO_STRETCH); 
    gridView.setPadding((int) padding, (int) padding, (int) padding, 
      (int) padding); 
    gridView.setHorizontalSpacing((int) padding); 
    gridView.setVerticalSpacing((int) padding); 
} 

そして、AlbumAdapterは以下のとおりです。 今私はそれらをGridViewに入れておきます。それで、setResourceのドロウアブルにImageViewを設定しています。

public MyAlbumAdapter(Context context, int columnWidth, String[] albumNameOnly) { 
     this.context = context; 
     Log.e("My Adapter Called", "++++"); 
     this.columnWidth = columnWidth; 
     this.albumNameOnly = albumNameOnly; 
    } 


    @Override 
    public int getCount() { 
     Log.e("Size of Directory", "++ " + albumNameOnly.length); 
     return MainActivity.directoryPath.size(); 
    } 

    @Override 
    public Object getItem(int position) { 
     return null; 
    } 

    @Override 
    public long getItemId(int position) { 
     return 0; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     View myGrid; 
     final ImageView imageView; 
     final TextView textView; 
     LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
     if (convertView == null) { 
      myGrid = new View(context); 
      myGrid = inflater.inflate(R.layout.album_grid_activity_layout, null); 
      imageView = (ImageView) myGrid.findViewById(R.id.no_image_placeholder); 
      textView = (TextView) myGrid.findViewById(R.id.album_title_main); 

      //   myImageView.setLayoutParams(new GridView.LayoutParams(200, 200)); 
      //   myImageView.setScaleType(ImageView.ScaleType.CENTER_CROP); 
//   myImageView.setPadding(1, 1, 1, 1); 
      imageView.setScaleType(ImageView.ScaleType.CENTER_CROP); 
      imageView.setLayoutParams(new GridView.LayoutParams(columnWidth, columnWidth)); 
      imageView.setImageResource(R.drawable.no_image); 
      Log.e("++++", "AlbuM Name to be displayed" + albumNameOnly[position]); 
      textView.setText(albumNameOnly[position]); 

     } else { 
      myGrid = (View) convertView.getTag(); 
     } 
     return myGrid; 
    } 

ここは私のGridViewレイアウトです。

<?xml version="1.0" encoding="utf-8"?> 
<GridView xmlns:android="http://schemas.android.com/apk/res/android" 
      android:id="@+id/grid_view" 
      android:layout_width="fill_parent" 
      android:layout_height="fill_parent" 
      android:background="#fffff"> 
</GridView> 

また、イメージとタイトルを設定するレイアウトです。

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
       android:orientation="vertical" 
       android:layout_width="match_parent" 
       android:layout_height="match_parent"> 

    <ImageView 
     android:layout_width="wrap_content" 
     android:layout_height="wrap_content" 
     android:id="@+id/no_image_placeholder"/> 
    <TextView 
     android:layout_width="match_parent" 
     android:id="@+id/album_title_main" 
     android:layout_height="wrap_content" 
     android:padding="12dip" 
     android:background="@android:color/tertiary_text_light" 
     android:textColor="@android:color/background_dark" 
     android:gravity="center" 
     android:layout_alignRight="@+id/no_image_placeholder" 
     android:layout_alignBottom="@+id/no_image_placeholder" 
     /> 

</RelativeLayout> 

この問題で私を助けてください。 私は助けに非常に感謝します。

Answer 1

アダプターのメモリー消費量とパフォーマンスを向上させるには、ViewHolderパターンを使用する必要があります。

static class ViewHolder { 
    TextView textView; 
    ImageView imageView; 
} 

@Override 
public View getView(int position, View convertView, ViewGroup parent) { 
    ViewHolder viewHolder; 
    if(convertView==null){ 
     // inflate the layout 
     LayoutInflater inflater = ((Activity) mContext).getLayoutInflater(); 
     convertView = inflater.inflate(layoutResourceId, parent, false); 

     // well set up the ViewHolder 
     viewHolder = new ViewHolder(); 
     viewHolder.textView = (TextView) convertView.findViewById(R.id.textView); 
     viewHolder.textView = (ImageView) convertView.findViewById(R.id.imageView); 

     //just need to set the image once, because all images will be same 
     //you can also set the image directly from XML 
     viewHolder.imageView.setImageResource(R.drawable.no_image); 

     // store the holder with the view. 
     convertView.setTag(viewHolder); 
    }else{ 
     // we will avoid call findViewById() on resource everytime 
     // just use the viewHolder 
     viewHolder = (ViewHolder) convertView.getTag(); 
    } 

    // object item based on the position 
    ObjectItem objectItem = data[position]; 

    // assign values if the object is not null 
    if(objectItem != null) { 
     viewHolder.textView.setText(objectItem.itemName); 
    } 
    return convertView; 
} 

あなたの問題は、私はグリッドとしてファイルフォルダを示すためRecyclerViewを実装

Answer 2

ViewHolderパターンを使用してconvertViewにタグを設定していない間、あなたは

else { 
     myGrid = (View) convertView.getTag(); 
    } 

を呼んでアクティビティ。

public class NewAlbumAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> { 
    String[] allAlbumName; 
    File[] filePathToAllAlbums; 
    ArrayList<File> firstImageOfAllFile; 
    Context context; 
    private static final int TYPE_HEADER = 2; 
    private static final int TYPE_ITEM = 1; 
    int countOfAlbums; 
    RecyclerViewClickListener recyclerViewClickListener; 


    public interface RecyclerViewClickListener { 
     void onClick(View view, int position); 

     void onLongClick(View view, int position); 
    } 

    public NewAlbumAdapter(Context context, File[] filePathToAllAlbums, String[] allAlbumName, int countOfAlbums, ArrayList<File> firstImageOfAllFile) { 
     this.context = context; 
     this.filePathToAllAlbums = filePathToAllAlbums; 
     this.allAlbumName = allAlbumName; 
     this.countOfAlbums = countOfAlbums; 
     this.firstImageOfAllFile = firstImageOfAllFile; 
    } 

    @Override 
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
     View view; 

//  view= LayoutInflater.from(context).inflate(R.layout.no_photo_album,parent,false); 
//  MyViewHolder myViewHolder=new MyViewHolder(view); 
//  return myViewHolder; 
//  if (viewType == TYPE_ITEM) { 
     view = LayoutInflater.from(context).inflate(R.layout.no_photo_album, parent, false); 
     return RecyclerItemViewHolder.newInstance(view); 
//  } else if (viewType == TYPE_HEADER) { 
//   view = LayoutInflater.from(context).inflate(R.layout.recycler_header, parent, false); 
//   return new RecyclerHeaderViewHolder(view); 
//  } 
//  throw new RuntimeException("There is no type that matches the type " + viewType + " + make sure your using types correctly"); 
    } 

    public int getBasicItemCount() { 
     return countOfAlbums == 0 ? 0 : allAlbumName.length; 
    } 

    @Override 
    public int getItemCount() { 
     return getBasicItemCount(); 
//  return getBasicItemCount()+1; //Use this for header 

    } 



    public boolean isPositionHeader(int position) { 
     return position == 0; 
    } 


    @Override 
    public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) { 
     View view; 
     RecyclerItemViewHolder itemHolder = (RecyclerItemViewHolder) holder; 
     if (firstImageOfAllFile.get(position) != null) { 
      Bitmap bitmap = BitmapFactory.decodeFile(firstImageOfAllFile.get(position).toString()); 
      itemHolder.setImageView(bitmap); 
     } else { 
      itemHolder.setImageView(R.drawable.no_photo_icon); 
     } 
     itemHolder.setAlbumTitle(allAlbumName[position]); 
     itemHolder.setNumberOfPic(String.valueOf(filePathToAllAlbums[position].list().length)); 

    } 
} 

Right now I am not showing any images which are currently there in the folders, so I am showing it with the drawable icon. 

And the items are being feeded into it using a item feeder. 

public class RecyclerItemViewHolder extends RecyclerView.ViewHolder { 
    private TextView albumTitle, numberOfPic; 
    private ImageView imageView; 

    public RecyclerItemViewHolder(View itemView, TextView albumTitle, TextView numberOfPic, ImageView imageView) { 
     super(itemView); 
     this.albumTitle = albumTitle; 
     this.numberOfPic = numberOfPic; 
     this.imageView = imageView; 
    } 

    public static RecyclerItemViewHolder newInstance(View parent){ 
     TextView albumTitle=(TextView)parent.findViewById(R.id.album_main_title_textview); 
     TextView numberOfPic=(TextView)parent.findViewById(R.id.number_of_pic_textview); 
     ImageView imageView=(ImageView)parent.findViewById(R.id.no_image_placeholder); 
     return new RecyclerItemViewHolder(parent,albumTitle,numberOfPic,imageView); 
    } 
    public void setAlbumTitle(String albumStringArray){ albumTitle.setText(albumStringArray); } 

    public void setNumberOfPic(String numberOfPicSetter){ 
     numberOfPic.setText(numberOfPicSetter); 
    } 

    public void setImageView(int imageId){ 
     imageView.setImageResource(imageId); 
    } 

    public void setImageView(Bitmap bitmap){ 

     imageView.setImageBitmap(bitmap); 
    } 

}

とアイテムは、アイテムフィーダクラスを使用RecyclerViewにfeededれます。

public class RecyclerItemViewHolder extends RecyclerView.ViewHolder { 
    private TextView albumTitle, numberOfPic; 
    private ImageView imageView; 

    public RecyclerItemViewHolder(View itemView, TextView albumTitle, TextView numberOfPic, ImageView imageView) { 
     super(itemView); 
     this.albumTitle = albumTitle; 
     this.numberOfPic = numberOfPic; 
     this.imageView = imageView; 
    } 

    public static RecyclerItemViewHolder newInstance(View parent){ 
     TextView albumTitle=(TextView)parent.findViewById(R.id.album_main_title_textview); 
     TextView numberOfPic=(TextView)parent.findViewById(R.id.number_of_pic_textview); 
     ImageView imageView=(ImageView)parent.findViewById(R.id.no_image_placeholder); 
     return new RecyclerItemViewHolder(parent,albumTitle,numberOfPic,imageView); 
    } 
    public void setAlbumTitle(String albumStringArray){ albumTitle.setText(albumStringArray); } 

    public void setNumberOfPic(String numberOfPicSetter){ 
     numberOfPic.setText(numberOfPicSetter); 
    } 

    public void setImageView(int imageId){ 
     imageView.setImageResource(imageId); 
    } 

    public void setImageView(Bitmap bitmap){ 

     imageView.setImageBitmap(bitmap); 
    } 


} 

これは、RecyclerViewでファイルフォルダを表示し、CardViewをレイアウトとして使用した方法です。

ご返信ありがとうございます。 そして、私は@Hendraと@Sandeepに感謝しています。