Android bitmap转文件（图片）保存到sd卡中

private void saveBitmap(Bitmap bitmap) throws IOException {
        File file = new File(Environment.getExternalStorageDirectory().getAbsolutePath() + "/" + mPicName + ".PNG");
        if (file.exists()) {
            file.delete();
        }
        FileOutputStream out;
        try {
            out = new FileOutputStream(file);
            if (bitmap.compress(Bitmap.CompressFormat.PNG, 100, out)) {
                out.flush();
                out.close();
            }
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }