我正在尝试将捕获的 .bmp 文件保存到 sdcard。这是负责此操作的代码片段:
    String root = Environment.getExternalStorageDirectory().toString();
    File mFolder = new File(root + "/mFolder");
    if (!mFolder.exists()) 
    {
        mFolder.mkdir();
    }
    String strF = mFolder.getAbsolutePath();
    File mSubFolder = new File(strF + "/MyApp-SubFolder");
    if (!mSubFolder.exists()) 
    {
        mSubFolder.mkdir();
    }
    String s = "myfile.png";
    File f = new File(mSubFolder.getAbsolutePath(),s);
    String strMyImagePath = f.getAbsolutePath();
    FileOutputStream fos = null;
    try 
    {
        fos = new FileOutputStream(f);
        bmp.compress(Bitmap.CompressFormat.PNG,70, fos);
        fos.flush();
        fos.close();
        Log.d("asd", "yeah!");
    //  MediaStore.Images.Media.insertImage(getContentResolver(), b, "Screen", "screen");
    }catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    }
}
但是有一个错误:
图片无效,大小为 0kb
我究竟做错了什么?