如何在Android中的GridView中显示文件夹？

时间：2016-04-06 06:36:12

标签： android file gridview

我有一个目录，我在其中有许多文件夹，我想在活动中GridView显示。

我已经提取了文件夹和标题的路径，但是如何在GridView中实现它的绘制空白。 我的代码是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); } 实现的。

AlbumAdapter

我的GridView在下面。 现在我只想在setResource中找到它们，这就是为什么我将ImageView 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; } 设置为可绘制的原因。

GridView

这是我的<?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> 布局。

<?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>

我正在为其设置图像和标题的布局。

{{1}}

请帮我解决这个问题。 我将非常感谢你的帮助。

2 个答案:

答案 0 :(得分：0)

您应该使用ViewHolder模式在适配器上获得更好的内存消耗和性能。

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;
}

你的问题是你打电话

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

虽然您没有使用ViewHolder模式将标记设置为convertView

答案 1 :(得分：0)

我实现了RecyclerView，以便在Activity中将文件夹显示为Grid。

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);
    }

}

使用物品输送器类将物品送入RecyclerView。

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);
    }


}

这就是我在RecyclerView中显示文件夹并使用CardView作为布局的方法。

很抱歉迟到的回复。 我很感谢@Hendra和@Sandeep的帮助。

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