코드

    public int saveImageToGallery(Bitmap bmp) {
        //    
        String root = Environment.getExternalStorageDirectory().getAbsolutePath();
        String dirName = "erweima16";
        File appDir = new File(root , dirName);
        if (!appDir.exists()) {
            appDir.mkdirs();
        }

        //      
        long timeStamp = System.currentTimeMillis();
        SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String sd = sdf.format(new Date(timeStamp));
        String fileName = sd + ".jpg";
        
        //    
        File file = new File(appDir, fileName);
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
            bmp.compress(Bitmap.CompressFormat.JPEG, 100, fos);
            fos.flush();
            //        
            ImageActivity.this.sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE,
                    Uri.fromFile(new File(file.getPath()))));
            return 2;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (fos != null) {
                    fos.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return -1;
    }