如何在RecyclerView Adapter中获取并显示视频文件夹大小

架构老林

2026-8-13

问题：视频文件夹大小无法显示

我正在开发一款视频播放App，已成功获取视频文件夹并在RecyclerView中展示，但无法显示视频文件夹的大小。相关代码如下：

VideoFoldersAdapter代码

package com.fun.rapidplayer;

import static java.security.AccessController.getContext;

import android.content.Context;
import android.content.res.AssetManager;
import android.graphics.Color;
import android.graphics.Typeface;
import android.graphics.drawable.GradientDrawable;
import android.os.FileUtils;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.cardview.widget.CardView;
import androidx.recyclerview.widget.RecyclerView;

import java.util.ArrayList;

public class VideoFoldersAdapter extends RecyclerView.Adapter<VideoFoldersAdapter.ViewHolder> {

    private ArrayList<MediaFiles> mediaFiles;
    private ArrayList<String> folderPath;
    private Context context;

    public VideoFoldersAdapter(ArrayList<MediaFiles> mediaFiles, ArrayList<String> folderPath, Context context) {
        this.mediaFiles = mediaFiles;
        this.folderPath = folderPath;
        this.context = context;
    }

    @NonNull
    @Override
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.floder_item,parent,false);
        return new ViewHolder(view);
    }

    @NonNull
    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {

        int indexPath = folderPath.get(position).lastIndexOf ("/");
        String nameOfFolder = folderPath.get(position).substring(indexPath+1);
        holder.folderName.setText(nameOfFolder);
        holder.nooffiles.setText(noOffiles(folderPath.get(position))+" Videos");
        String size = how to get please help

    }

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

    public class ViewHolder extends RecyclerView.ViewHolder {
        TextView folderName;
        TextView nooffiles;
        TextView foldersize;
        CardView cardview1,cardview2;
        public ViewHolder(@NonNull View itemView) {
            super(itemView);
            folderName = itemView.findViewById(R.id.folderName);
            nooffiles = itemView.findViewById(R.id.nooffiles);
            foldersize = itemView.findViewById(R.id.foldersize);
            cardview1 = itemView.findViewById(R.id.cardview1);
            cardview2 = itemView.findViewById(R.id.cardview2);
  

        }

    }

    int noOffiles(String folder_name) {
        int files_no = 0;
        for (MediaFiles mediaFiles : mediaFiles) {
            if (mediaFiles.getPath().substring(0, mediaFiles.getPath().lastIndexOf("/"))
                    .endsWith(folder_name)) {
                files_no++;
            }

        }
        return files_no;
    }

    public void _shapeRadius(final View _v, final String _color, final double _radius) {
        android.graphics.drawable.GradientDrawable shape = new android.graphics.drawable.GradientDrawable();
        shape.setShape(android.graphics.drawable.GradientDrawable.RECTANGLE);

        shape.setCornerRadius((int)_radius);

        shape.setColor(Color.parseColor(_color));
        _v.setBackgroundDrawable(shape);
    }

    private String bytesIntoHumanReadable(long bytes) {
        long kilobyte = 1024;
        long megabyte = kilobyte * 1024;
        long gigabyte = megabyte * 1024;
        long terabyte = gigabyte * 1024;

        if ((bytes >= 0) && (bytes < kilobyte)) {
            return bytes + " B";

        } else if ((bytes >= kilobyte) && (bytes < megabyte)) {
            return (bytes / kilobyte) + " KB";

        } else if ((bytes >= megabyte) && (bytes < gigabyte)) {
            return (bytes / megabyte) + " MB";

        } else if ((bytes >= gigabyte) && (bytes < terabyte)) {
            return (bytes / gigabyte) + " GB";

        } else if (bytes >= terabyte) {
            return (bytes / terabyte) + " TB";

        } else {
            return bytes + " Bytes";
        }
    }

}

MediaFiles模型类代码

package com.fun.rapidplayer;

public class MediaFiles {

    public String id;
    public String title;
    public String displayNam;
    public String size;
    public String duration;
    public String path;
    public String datAdded;

    public MediaFiles(String id, String title, String displayNam, String size, String duration, String path, String datAdded) {
        this.id = id;
        this.title = title;
        this.displayNam = displayNam;
        this.size = size;
        this.duration = duration;
        this.path = path;
        this.datAdded = datAdded;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public String getDisplayNam() {
        return displayNam;
    }

    public void setDisplayNam(String displayNam) {
        this.displayNam = displayNam;
    }

    public String getSize() {
        return size;
    }

    public void setSize(String size) {
        this.size = size;
    }

    public String getDuration() {
        return duration;
    }

    public void setDuration(String duration) {
        this.duration = duration;
    }

    public String getPath() {
        return path;
    }

    public void setPath(String path) {
        this.path = path;
    }

    public String getDatAdded() {
        return datAdded;
    }

    public void setDatAdded(String datAdded) {
        this.datAdded = datAdded;
    }
}

MainActivity代码

package com.fun.rapidplayer;

import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

import android.annotation.SuppressLint;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.provider.MediaStore;

import java.util.ArrayList;


public class MainActivity extends AppCompatActivity {

    private ArrayList<MediaFiles> mediaFiles = new ArrayList<>();
    private ArrayList<String> allfolderList = new ArrayList<>();
    RecyclerView recyclerview1;
    VideoFoldersAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        recyclerview1 = findViewById(R.id.recyclerview1);
        showfolder();
    }

    private void showfolder() {
        mediaFiles = fetchMedeia();
        adapter = new VideoFoldersAdapter(mediaFiles, allfolderList, this);
        recyclerview1.setAdapter(adapter);
        recyclerview1.setLayoutManager(new LinearLayoutManager(this,
                recyclerview1.VERTICAL, false));
        adapter.notifyDataSetChanged();
    }

    public ArrayList<MediaFiles> fetchMedeia() {
        ArrayList<MediaFiles> mediaFilesArrayList = new ArrayList<>();
        Uri uri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;

        Cursor cursor = getContentResolver().query(uri, null, null, null, null);

        if (cursor != null && cursor.moveToNext()) {
            do {
                String id = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media._ID));
                String title = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media.TITLE));
                String displayName = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media.DISPLAY_NAME));
                String size = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media.SIZE));
                String duration = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media.DURATION));
                String path = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media.DATA));
                String dateAdded = cursor.getString(cursor.getColumnIndex(MediaStore.Video.Media.DATE_ADDED));
                MediaFiles mediaFiles = new MediaFiles(id, title, displayName, size, duration, path, dateAdded);


                int index = path.lastIndexOf("/");
                String substring = path.substring(0, index);
                if (!allfolderList.contains(substring)) {
                    allfolderList.add(substring);
                }
                mediaFilesArrayList.add(mediaFiles);
            } while (cursor.moveToNext());
        }

        return mediaFilesArrayList;
    }
}

解决方案

要计算并显示视频文件夹的总大小，只需遍历目标文件夹下所有视频的大小并求和，再转换为可读格式即可，具体修改如下：

1. 添加文件夹总大小计算方法

在VideoFoldersAdapter类中新增方法，用于统计指定文件夹下所有视频的总字节数：

private long calculateFolderTotalSize(String folderPath) {
    long totalSize = 0;
    for (MediaFiles file : mediaFiles) {
        // 获取当前视频所在的文件夹路径
        String fileFolder = file.getPath().substring(0, file.getPath().lastIndexOf("/"));
        // 匹配目标文件夹，累加视频大小
        if (fileFolder.equals(folderPath)) {
            try {
                totalSize += Long.parseLong(file.getSize());
            } catch (NumberFormatException e) {
                e.printStackTrace();
            }
        }
    }
    return totalSize;
}

2. 在绑定ViewHolder时计算并设置大小

修改onBindViewHolder方法，调用上述方法计算大小并显示到对应的TextView：

@NonNull
@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
    int indexPath = folderPath.get(position).lastIndexOf("/");
    String nameOfFolder = folderPath.get(position).substring(indexPath + 1);
    holder.folderName.setText(nameOfFolder);
    holder.nooffiles.setText(noOffiles(folderPath.get(position)) + " Videos");
    
    // 计算文件夹总大小并转换为可读格式
    long totalBytes = calculateFolderTotalSize(folderPath.get(position));
    String readableSize = bytesIntoHumanReadable(totalBytes);
    holder.foldersize.setText(readableSize);
}

3. 可选优化建议

如果视频文件数量较多，建议在后台线程中计算总大小，避免阻塞UI线程（可使用Coroutine或AsyncTask实现）
可以缓存已计算的文件夹大小，避免每次绑定ViewHolder时重复遍历计算
完善异常处理逻辑，避免因视频大小格式异常导致崩溃

内容的提问来源于stack exchange，提问作者Ayan Mishra

如何在RecyclerView Adapter中获取并显示视频文件夹大小

VideoFoldersAdapter代码 #

MediaFiles模型类代码 #

MainActivity代码 #

1. 添加文件夹总大小计算方法 #

2. 在绑定ViewHolder时计算并设置大小 #