基于SD卡得文件选择器

◦public class ActivityFilePicker extends Activity {   
◦  
◦        private ListView listViewFilePicker;   
◦        private File mCurrentDirectory = new File(Environment.getExternalStorageDirectory().getAbsolutePath()); //根目录位置   
◦        AdapterFilePicker mFileAdapter; //ListView适配器   
◦        String fileEndings[] = { "mp3" };       //显示的文件类型   
◦  
◦        @Override  
◦        public void onCreate(Bundle savedInstanceState) {   
◦                super.onCreate(savedInstanceState);   
◦                setContentView(R.layout.layout_activityfilepicker);   
◦                listViewFilePicker = (ListView) findViewById(R.id.listview);   
◦                listViewFilePicker.setCacheColorHint(0x00000000);   
◦                mFileAdapter = new AdapterFilePicker(this);   
◦                listViewFilePicker.setAdapter(mFileAdapter);   
◦                //Item点击事件   
◦                ListView.OnItemClickListener lv2click = new ListView.OnItemClickListener() {   
◦                        public void onItemClick(AdapterView parent, View view,   
◦                                        int position, long id) {   
◦                                int fid = mFileAdapter.getItemType((int) id);   
◦                                String mPath = "";   
◦                                if (fid == 1) { //文件类型1为文件夹，点击进入该文件夹目录   
◦                                        String s1 = mFileAdapter.getItem((int) id).name;   
◦                                        if (s1.equals("..")) {   
◦                                                mPath = mCurrentDirectory.getParent();   
◦                                        } else {   
◦                                                mPath = mCurrentDirectory.getPath() + "/" + s1 + "/";   
◦                                        }   
◦                                        mCurrentDirectory = new File(mPath);   
◦                                        ListFile(mCurrentDirectory);   
◦                                } else { //返回选中的文件的Path   
◦                                        Bundle bundle = new Bundle();   
◦                                        bundle.putString("path", mCurrentDirectory.getPath()   
◦                                                        + "/" + mFileAdapter.getItem((int) id).name);   
◦                                        Intent mIntent = new Intent();   
◦                                        mIntent.putExtras(bundle);   
◦                                        setResult(RESULT_OK, mIntent);   
◦                                        ActivityFilePicker.this.finish();   
◦                                }   
◦                        }   
◦                };   
◦                ListFile(mCurrentDirectory);   
◦                listViewFilePicker.setOnItemClickListener(lv2click);   
◦        }   
◦  
◦        /**  
◦         * 列出该目录的文件  
◦         * @param aDirectory  
◦         */  
◦        private void ListFile(File aDirectory) {   
◦                mFileAdapter.clearItems();   
◦                mFileAdapter.notifyDataSetChanged();   
◦                listViewFilePicker.postInvalidate();   
◦                if (!aDirectory.getPath().equals("/sdcard")) {   
◦                        FileData fd = new FileData();   
◦                        fd.name = "..";   
◦                        fd.type = 1;   
◦                        mFileAdapter.addItem(fd);   
◦                }   
◦                for (File f : aDirectory.listFiles()) {   
◦                        if (f.isDirectory()) {   
◦                                FileData fd = new FileData();   
◦                                fd.name = f.getName();   
◦                                fd.type = 1;   
◦                                mFileAdapter.addItem(fd);   
◦                        } else {   
◦                                if (checkEnds(f.getName().toLowerCase())) {   
◦                                        FileData fd = new FileData();   
◦                                        fd.name = f.getName();   
◦                                        fd.type = 0;   
◦                                        mFileAdapter.addItem(fd);   
◦                                }   
◦                        }   
◦                }   
◦                mFileAdapter.notifyDataSetChanged();   
◦                listViewFilePicker.postInvalidate();   
◦        }   
◦  
◦        private boolean checkEnds(String checkItsEnd) {   
◦                for (String aEnd : fileEndings) {   
◦                        if (checkItsEnd.endsWith(aEnd))   
◦                                return true;   
◦                }   
◦                return false;   
◦        }   
◦}  

由于模块结构很简单，所以把遍历文件的方法放在Activity上了

◦public class AdapterFilePicker extends BaseAdapter {   
◦        private Context mContext;   
◦        private Vector mItems = new Vector();   
◦        private LinearLayout layout, layout_more;   
◦        private LayoutInflater inflate;   
◦        private TextView textViewItem;   
◦  
◦        public AdapterFilePicker(Context context) {   
◦                mContext = context;   
◦                inflate = (LayoutInflater) mContext   
◦                                .getSystemService(android.content.Context.LAYOUT_INFLATER_SERVICE);   
◦        }   
◦  
◦        public void addItem(FileData item) {   
◦                mItems.add(item);   
◦        }   
◦  
◦        public FileData getItem(int it) {   
◦                return (FileData) mItems.elementAt(it);   
◦        }   
◦  
◦        public int getCount() {   
◦                return mItems.size();   
◦        }   
◦  
◦        public long getItemId(int arg0) {   
◦                return arg0;   
◦        }   
◦  
◦        public int getItemType(int arg0) {   
◦                return getItem(arg0).type;   
◦        }   
◦  
◦        public void clearItems() {   
◦                mItems.clear();   
◦        }   
◦  
◦        public View getView(int position, View view, ViewGroup arg2) {   
◦                if(null == view){   
◦                        view = (LinearLayout) inflate.inflate(R.layout.item_filepicker_listview, null);   
◦                }   
◦                textViewItem = (TextView) view.findViewById(R.id.textViewFileName);   
◦                textViewItem.setText(getItem(position).name);   
◦                return view;   
◦        }   
◦  
◦}  

◦/** 
◦ * 文件结构 
◦ * @author Administrator 
◦ * 
◦ */ 
◦public class FileData {  
◦                public String name; //文件名  
◦                public int type; //文件类型  
◦}