根据路径遍历该路径下的文件夹和文件并以列表形式显示出来、文件（夹）的复制

  /**根据给定的一个文件夹路径字符串遍历出这个文
     * 件夹中包含的文件名称并配置到ListView列表中*/
    private void initFileListInfo(String filePath){
        isAddBackUp = false;
        mCurrentFilePath = filePath;
        //显示当前的路径
        mPath.setText(filePath);
        mFileName = new ArrayList<String>();
        mFilePaths = new ArrayList<String>();
        File mFile = new File(filePath);
        //遍历出该文件夹路径下的所有文件/文件夹
        File[] mFiles = mFile.listFiles();
        //只要当前路径不是手机根目录或者是sd卡根目录则显示“返回根目录”和“返回上一级”
        if(menuPosition == 1&&!mCurrentFilePath.equals(mRootPath)){
            initAddBackUp(filePath,mRootPath);
        }else if(menuPosition == 2&&!mCurrentFilePath.equals(mSDCard)){
            initAddBackUp(filePath,mSDCard);
        }
        
        /*将所有文件信息添加到集合中*/
        for(File mCurrentFile:mFiles){
            mFileName.add(mCurrentFile.getName());
            mFilePaths.add(mCurrentFile.getPath());
        }
        
        /*适配数据*/ setListAdapter设置listView的适配器，要集成自ListActivity
        setListAdapter(new FileAdapter(MainActivity.this,mFileName,mFilePaths));
    }

 接着是列表的适配器（继承自BaseAdapter），要复写getCount()、getItem()、getItemId()以及getView()函数。

    //自定义Adapter内部类
    class FileAdapter extends BaseAdapter{
        //返回键，各种格式的文件的图标
        private Bitmap mBackRoot;
        private Bitmap mBackUp;
        private Bitmap mImage;
        private Bitmap mAudio;
        private Bitmap mRar;
        private Bitmap mVideo;
        private Bitmap mFolder;
        private Bitmap mApk;
        private Bitmap mOthers;
        private Bitmap mTxt;
        private Bitmap mWeb;
        
        private Context mContext;
        //文件名列表
        private List<String> mFileNameList;
        //文件对应的路径列表
        private List<String> mFilePathList;
        
        public FileAdapter(Context context,List<String> fileName,List<String> filePath){
            mContext = context;
            mFileNameList = fileName;
            mFilePathList = filePath;
            //初始化图片资源
            //返回到根目录
            mBackRoot = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.back_to_root);
            //返回到上一级目录
            mBackUp = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.back_to_up);
            //图片文件对应的icon
            mImage = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.image);
            //音频文件对应的icon
            mAudio = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.audio);
            //视频文件对应的icon
            mVideo = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.video);
            //可执行文件对应的icon
            mApk = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.apk);
            //文本文档对应的icon
            mTxt = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.txt);
            //其他类型文件对应的icon
            mOthers = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.others);
            //文件夹对应的icon
            mFolder = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.folder);
            //zip文件对应的icon
            mRar = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.zip_icon);
            //网页文件对应的icon
            mWeb = BitmapFactory.decodeResource(mContext.getResources(),R.drawable.web_browser);
        }
        //获得文件的总数
        public int getCount() {
            return mFilePathList.size();
        }
        //获得当前位置对应的文件名
        public Object getItem(int position) {
            return mFileNameList.get(position);
        }
        //获得当前的位置
        public long getItemId(int position) {
            return position;
        }
        //获得视图
        public View getView(int position, View convertView, ViewGroup viewgroup) {
            ViewHolder viewHolder = null;
            if (convertView == null) {
                viewHolder = new ViewHolder();
                LayoutInflater mLI = (LayoutInflater)mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
                //初始化列表元素界面
                convertView = mLI.inflate(R.layout.list_child, null);
                //获取列表布局界面元素
                viewHolder.mIV = (ImageView)convertView.findViewById(R.id.image_list_childs);
                viewHolder.mTV = (TextView)convertView.findViewById(R.id.text_list_childs);
                //将每一行的元素集合设置成标签
                convertView.setTag(viewHolder);
            } else {
                //获取视图标签
                viewHolder = (ViewHolder) convertView.getTag();
            }
            File mFile = new File(mFilePathList.get(position).toString());
            //如果
            if(mFileNameList.get(position).toString().equals("BacktoRoot")){
                //添加返回根目录的按钮
                viewHolder.mIV.setImageBitmap(mBackRoot);
                viewHolder.mTV.setText("返回根目录");
            }else if(mFileNameList.get(position).toString().equals("BacktoUp")){
                //添加返回上一级菜单的按钮
                viewHolder.mIV.setImageBitmap(mBackUp);
                viewHolder.mTV.setText("返回上一级");
            }else if(mFileNameList.get(position).toString().equals("BacktoSearchBefore")){
                //添加返回搜索之前目录的按钮
                viewHolder.mIV.setImageBitmap(mBackRoot);
                viewHolder.mTV.setText("返回搜索之前目录");
            }else{
                String fileName = mFile.getName();
                viewHolder.mTV.setText(fileName);
                if(mFile.isDirectory()){
                    viewHolder.mIV.setImageBitmap(mFolder);
                }else{
                    String fileEnds = fileName.substring(fileName.lastIndexOf(".")+1,fileName.length()).toLowerCase();//取出文件后缀名并转成小写
                    if(fileEnds.equals("m4a")||fileEnds.equals("mp3")||fileEnds.equals("mid")||fileEnds.equals("xmf")||fileEnds.equals("ogg")||fileEnds.equals("wav")){
                        viewHolder.mIV.setImageBitmap(mVideo);
                    }else if(fileEnds.equals("3gp")||fileEnds.equals("mp4")){
                        viewHolder.mIV.setImageBitmap(mAudio);
                    }else if(fileEnds.equals("jpg")||fileEnds.equals("gif")||fileEnds.equals("png")||fileEnds.equals("jpeg")||fileEnds.equals("bmp")){
                        viewHolder.mIV.setImageBitmap(mImage);
                    }else if(fileEnds.equals("apk")){
                        viewHolder.mIV.setImageBitmap(mApk);
                    }else if(fileEnds.equals("txt")){
                        viewHolder.mIV.setImageBitmap(mTxt);
                    }else if(fileEnds.equals("zip")||fileEnds.equals("rar")){
                        viewHolder.mIV.setImageBitmap(mRar);
                    }else if(fileEnds.equals("html")||fileEnds.equals("htm")||fileEnds.equals("mht")){
                        viewHolder.mIV.setImageBitmap(mWeb);
                    }else {
                        viewHolder.mIV.setImageBitmap(mOthers);
                    }
                }                
            }
            return convertView;
        }
        //用于存储列表每一行元素的图片和文本
        class ViewHolder {
            ImageView mIV;
            TextView mTV;
        }
    }

 文件（夹）的复制（用FileInputStream的read（）方法逐个字节读入，同时用FileOutputStream逐个字节写入文件）。

  private int i;
    FileInputStream fis;
    FileOutputStream fos;
    //复制文件
    private void copyFile(String oldFile,String newFile){
        try {
            fis =  new FileInputStream(oldFile);
            fos = new FileOutputStream(newFile);
            do{
                //逐个byte读取文件，并写入另一个文件中
                if((i = fis.read()) != -1){
                    fos.write(i);
                }
            }while(i != -1);
            //关闭输入文件流
            if(fis != null){
                fis.close();
            }
            //关闭输出文件流
            if(fos != null){
                fos.close();
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }