在授予根权限之前，应用程序布局不会绘制\\拒绝

Question

I'm a beginner android developer and trying to learn stuff while making a sample app.

my MainActivity's onCreate() execute an AsyncTask that fetches data for my RecyclerView to hold. the AsyncTask requires Root access and "asks" for it.

my problem is that the MainActivity's layout wont draw until the Root Prompt appears and i click grant\\deny.

how can i make the layout draw beforehand?

Thanks in Advance!!!

onCreate():

super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
...
DataFetcher dataFetcher = new DataFetcher();
dataFetcher.execute("");

dataFetcher:

@Override
    protected void onPreExecute() {
        super.onPreExecute();
        if(!canRunRootCommands()) {
            Log.e("DataFetcher", "No Root Access");
            cancel(true);
        }
    }
/***********************************************************************/
    //Root Check method
    //Credit: http://muzikant-android.blogspot.co.il/2011/02/how-to-get-root-access-and-execute.html

    /***********************************************************************/
    private boolean canRunRootCommands() {
        boolean retval = false;
        Process suProcess;

        try {
            suProcess = Runtime.getRuntime().exec("su");

            DataOutputStream os = new DataOutputStream(suProcess.getOutputStream());
            DataInputStream osRes = new DataInputStream(suProcess.getInputStream());

            if (null != os && null != osRes) {
                // Getting the id of the current user to check if this is root
                os.writeBytes("id\n");
                os.flush();

                String currUid = osRes.readLine();
                boolean exitSu = false;
                if (null == currUid) {
                    retval = false;
                    exitSu = false;
                    Log.d("ROOT", "Can't get root access or denied by user");
                } else if (true == currUid.contains("uid=0")) {
                    retval = true;
                    exitSu = true;
                    Log.d("ROOT", "Root access granted");
                } else {
                    retval = false;
                    exitSu = true;
                    Log.d("ROOT", "Root access rejected: " + currUid);
                }

                if (exitSu) {
                    os.writeBytes("exit\n");
                    os.flush();
                }
            }
        } catch (Exception e) {
            // Can't get root !
            // Probably broken pipe exception on trying to write to output stream (os) after su failed, meaning that the device is not rooted

            retval = false;
            Log.d("ROOT", "Root access rejected [" + e.getClass().getName() + "] : " + e.getMessage());
        }

        return retval;
    }

Answer 1

将“ canRunRootCommands（）”调用从onPreExecute移至doInBackground，以确保其未在UI线程上运行。