如果你不想使用mediastore，你可以像这样使用内部存储

void saveBitmap(Bitmap bitmap) {
    File dir = getFilesDir(); // or getCacheDir()
    if (!new File(dir + "/folderName").isDirectory()) {
        if (new File(dir + "/folderName").mkdir()) { // directory made successfully
            dir = new File(dir + "/folderName/" + "fileName.ext");
        } else { // error making the directory
            return;
        }
    } else {
        dir = new File(dir + "/folderName/" + "fileName.ext");
    }

    try {
        FileOutputStream fileOutputStream = new FileOutputStream(dir);
        bitmap.compress(Bitmap.CompressFormat.PNG, 100, fileOutputStream);
        fileOutputStream.close();
    } catch (Exception e) {
        e.printStackTrace();
    }
}

检索位图

Bitmap loadBitmap(File dir) {
    Bitmap bitmap = null;
    try {
        FileInputStream fileInputStream = new FileInputStream(dir);
        bitmap = BitmapFactory.decodeStream(fileInputStream);
        fileInputStream.close();
    } catch(Exception e) {
        e.printStackTrace();
    }

    return bitmap;
}