private void SavedToText(Context context, String stringToWrite) {

        if (Environment.MEDIA_MOUNTED.equals(Environment

                .getExternalStorageState())) {

            String foldername = Environment.getExternalStorageDirectory()

                    .getPath() + "/log";

            File folder = new File(foldername);

            if (folder == null || !folder.exists()) {

                folder.mkdir();

            }

            String fileName = "/locLog" + ".txt";

            File targetFile = new File(foldername + fileName);

            OutputStreamWriter osw;

            try {

                if (!targetFile.exists()) {

                    targetFile.createNewFile();

                    osw = new OutputStreamWriter(new FileOutputStream(

                            targetFile), "utf-8");

                    osw.write(stringToWrite);

                    osw.close();

                } else {

                    osw = new OutputStreamWriter(new FileOutputStream(

                            targetFile, true), "utf-8");

                    osw.write("\n" + stringToWrite);

                    osw.flush();

                    osw.close();

                }

            } catch (Exception e) {

                // Toast.makeText(context,e.toString(),Toast.LENGTH_LONG).show();

            }

        } else {

            // Toast.makeText(context,"未发现SD卡！",Toast.LENGTH_LONG).show();

        }

}

private String readFromFile(Context context){

        if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {

            String foldername = Environment.getExternalStorageDirectory().getPath()+ "/eryaApp";

            File folder = new File(foldername);

            if (folder == null || !folder.exists()) {

                folder.mkdir();

            }

            File targetFile=new File("/sdcard/eryaApp/eryaShoppingList.txt");

            String readedStr="";

             try{

                if(!targetFile.exists()){

                    targetFile.createNewFile();

                    return "No File error ";

                }else{

                     InputStream in = new BufferedInputStream(new FileInputStream(targetFile));

                     BufferedReader br= new BufferedReader(new InputStreamReader(in, "UTF-8"));

                     String tmp;

                     while((tmp=br.readLine())!=null){

                         readedStr+=tmp;

                     }

                     br.close();

                     in.close();

                     return readedStr;

                }

             } catch (Exception e) {

                    Toast.makeText(context,e.toString(),Toast.LENGTH_LONG).show();

                    return e.toString();

             }

        }else{

            Toast.makeText(context,"未发现SD卡！",Toast.LENGTH_LONG).show();

            return "SD Card error";

        }

    }